# Webster Engine fails to start



## serhat (Mar 30, 2010)

Hello,

I have finished my webster engine and planning to run on glow plug for a while.
O.S. .12cc glow plug engine carburetor,A3 glow plug and %10nitro/%18 oil aircraft fuel are used as suggested by Joe.
I am sure about the compression and timing,however it does not work.
Do you have any idea about the type of glow plug to be used on this engine?
Thanks for any other suggestions/comments.

Brgds


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## Ed T (Mar 30, 2010)

Glow ignition engines are glow assisted diesel engines. That is, they rely, to a significant extent, on the heat generated by compression to fire off the mixture. They also have the glow plug to provide a bit of heat especially for starting. ASSUMING that the valve timing and all are correct the most likely cause of failing to run is that the compression is too low. I don't know what the nominal design compression of the Webster is, but I'd bet it's a bit on the "relaxed " side to make a pleasant running ignition engine. This low compression may be inadequate for the glow ignition. The relatively low RPM and 4 cycle operation may mean that you will have to keep the glow plug powered all the time, rather than just at starting, since there will not be a lot of "fire" to keep it hot, There are also plugs made specifically for four cycle glow engines which help with these issues. That said, there may be along and illustrious history of these engines running perfectly on glow plugs. I don't know. I'd still be inclined to look to the compression first. Could be bad valve sealing, just not enough in any case, poor piston seal, dimensional error on any of several parts (it wouldn't take much), bad glow-plug battery, old fuel ( this can really keep you guessing).
 If there's compression, fuel, air, and fire (from something) it should at least fire once. Getting it to do it several time in a row is an added challenge. Good luck!!


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## bearcar1 (Mar 30, 2010)

All of the above things could be causing you problems but two things spring to my feeble mind that may possibly be exacerbating the starting/running issues. The first that I wondered about is the size of carburetor being used, if the venturi throat is too large there may not be sufficient fuel 'draw' to initiate a good charge to the cylinder. The second thing is coupled with that statement and regards the distance the charge has to travel ei: how far away from the cylinder the carb is. Again if the distance is too great, the valves may not be open long enough to effectively pull the charge into the combustion chamber. It is difficult to tell but all of these factors can and do come into play. Begin by eliminating the obvious potential problems first such as being certain the plug is in fact being lit by the battery and that the battery is in fact capable of performing that function. It may be that you will have to supply constant voltage to the plug in order to maintain good running. Let us know what you have/have not done as far as eliminating some of these basic factors, I'm sure that the combined knowledge on the forum can get this thing to start and remain running, hopefully without a great deal of rework. A very handsome engine BTW, I do like the polished copper fuel vessel.

BC1
Jim


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## crankshafter (Mar 30, 2010)

Serhat.
Nice engine.
When I look at your Webster the first that comes to mind is that the intake valve- spring seems to be a little bit stiff. Try with a real week spring, you only need a spring that is just closing the valve. Do you have blow-back in the fuel-line? If so make a small fuel controll- valve and place it in the fuel-line just below the fuel inlet of the carb. How do I know oh: :noidea:
Just my 2cent.

brgds
Crankshafter


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## serhat (Mar 30, 2010)

Thank you Ed and Jim,

Let me tell you what I have done so far to fix the problem.
First of all,to be sure about the compression,I have replaced the bronze piston rings with o rings (qty 2) so the compression is perfect now.I am also sure about the valves as I have tried them several times and they close and open perfectly.
Jim,
you mentioned about the distance between the carb venturi and the cylinder,its really an interesting point.I have never taken this point into consideration.It is around one and a half inch.
My battery is 1800ma and 1.2 volt.Do you think that it is not sufficient for a good glow?
By the way,the fuel I am using isfresh,purchased last week.

Waiting your comments
Thanks


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## serhat (Mar 30, 2010)

Hi Crankshafter,

Thank you.
I have changed that spring several times.It is just closing the valve and opens easily with the compression but of course not more than 1-2 mm.
What do you mean by fuel regulator? The carb has an inlet adjustment needle.Is it something different?


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## crankshafter (Mar 30, 2010)

Serhat.
Here is my starting procedure: Open the throttle to 1/4( aprox.) Ignition on. One finger to open the intakevalve, thumb to close the intake on the carb, flip the engine couple of times to draw fuel in to the cyl., fingers away from valve and intake and flip- flip, of it goes.This works for me, BTW: I use points/coil, and 95 octane ;D. 
Here you can see the small contoll-valve right at my thumb, it has a small bearing- ball inside to prevent the fuel from being blown back in to the fuelline/tank.




One more thing do you have a went.-hole in the fillercap :
PS: if you like I will dismantle the controll-valve and take a pic. of it.
CS.


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## serhat (Mar 30, 2010)

Hi CS,

I do the same to fill the cylinder with some fuel prior to first attempt but it didnot work.Ignition system has a powerful spark and totally different from the glow plug.
I would like to see the detals of your control valve.

Thanks again.


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## crankshafter (Mar 30, 2010)

Hi again.
I will dismantel the controllvalve and take some pics. hopefully tomorrow 
CS


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## Ed T (Mar 30, 2010)

The compression seal and the valve seals may all be perfect and you can still have too little compression to initiate ignition. The 1800 mah battery should be fine for this purpose if it's charged up. I presume you've looked at the glow plug when hooked up to the battery just to check out that sub-system. It should glow bright orange/yellow. While you have the plug out, you might inject a few drops of fuel into the cylinder and see if you can get it to fire off of a prime. If so, it would point you in the direction of the fuel supply as discussed above. Failure to fire on the prime would point in the direction of the compression or the glow plug. If you have transparent/lucent fuel lines you should be able to see the fuel move toward the carb if you choke the carb with your finger and turn the engine over. Just like choking any other engine, this should draw fuel into the intake system. Is the glow-plug an idle bar plug? If not, that might help keep the filament hot.


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## serhat (Mar 30, 2010)

Hi Ed,

No it is not an idle-bar plug.
I will purchase an F type glow plug for 4 cycle engines and if available with an idle bar,tomorrow.
If it does not work with the new plug and maybe with a new 1,5V baterry,I will directlt switch to ignition system.


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## crankshafter (Mar 31, 2010)

Hi serhat
I have a couple of pic. of the controll-valve. Here we go:










In/ outlet 2.4mm drill, 5mm thread in the valve-cage, on the other half a small o-ring for sealing. in the outlet bore ,a thin wire to prevent the ball to be sucked up and restrict the outlet. Hope you understand. ;D
Ah so you comes from Turkey. I been there several times. Side,Marmaris,Alanya, and so on. Nice contry/peoples 
CS


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## serhat (Apr 1, 2010)

Hi CS,

It is a very nice check valve.I'll try to do it.
The F type glow plug will come tomorrow.Lets see if it will add some value or not.

I live in Istanbul but travel to south of Turkey every summer.I would like to welcome you in Istanbul on your next visit to Turkey.

You can see my other engines and model boats I have built on below blog

serhatece.blogspot.com

Brgds


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## serhat (Apr 4, 2010)

Hello,

The new glow plug F type also did not work.I have injected some fuel before replacing the new glow plug(as suggested by Ed).
Engine started for a 3 or 4 turns and stopped again.
So the reason of failure is unsufficient fuel/air supply.
What I have done?

1- replaced the o rings on the piston and once again became sure about the compression.
2- Replaced the intake spring with a more softer one.It works fine on the tests.

Result:

Nothing changed.

As it has been advised by bearcar1 ,the intake system on this engine has a long way to cylinder and even a good compression is not sufficient for a proper operation.
Another important point is still the glow plug which is not providing enough heat as a spark generated by a standart ignition system.


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## Ed T (Apr 4, 2010)

That' some progress. It has now run infinitely more than it had before. I have to ask because I don't know your level of experience with these things so don't be insulted. Did you open the needle valve on the carb? When the NV is open some and you choke the engine and turn it over you should suck a ton of fuel into the carb/intake. This should be pretty obvious. Fuel dripping out of the carb etc. If this doesn't happen, something is amiss. So, try that and we'll go from there.  Good luck!!


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## serhat (Apr 5, 2010)

Hello Ed,

Yes.I have tried several needle openings,1 turn,2 turns and even 3 turns.Normally it should work with one and a half turn.
The carburetor I am using does not have a venturi or a very light one.Do you think that can effect the flow of fuel to the cylinder?
 I have added some pictures of it.


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## metalmad (Apr 5, 2010)

Hi serhat
very nice looking Webster,mine would not run until I made gaskits for the valve block
Im not much of a machinest im afraid lol
and I agree with crankshafter about the intake spring, it does look to my old eyes a little heavy.
Cheers Pete


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## Ed T (Apr 5, 2010)

AHA!! a clue.If the carb you are using does not have a venturi ,to speak of, it is not going to draw fuel very well if at all. This is especially the case since the engine you have is moving far less air than the two cycle engine the carb was intended for. Many two cycle engines , especially in car applications, are intended to run at full throttle most of the time and utilize a pressurized fuel system to maximize performance. This greatly reduces the need for the vacuum created by the venturi for fuel delivery (eliminates it in some cases) and increases performance. I have played with an off road r/c car and it won't run without the tank pressurized. So, the lack of a venturi certainly is not working in your favor. 
A QUICK look at your nice model did not reveal a vent on the fuel tank. Maybe I just didn't see it. This too will prevent the engine from running well if at all and the weak fuel draw will only make the effect worse. Of course, if you decide to pressurize the system, you won't want a vent, but pressurizing with the engine you have would not be pretty. The fuel feed issues are independent of the ignition system, so you're going to have to figure it out to get it to work.


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## cobra428 (Apr 5, 2010)

serhat,
Most model engines use muffler pressure into the fuel tank then out to the carb (sealed system). So you may have to open the needle valve more. If you choke it (finger over venturi) do you get a pop out of it? Make sure your glow plug ligthts a very bright red.

Tony


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## serhat (Apr 6, 2010)

Hello,

Metalmad,

I have already changed the intake spring.The one you see on the picture is the old one.The new one is softer.I added a picture of it.I used gaskets between the layers of the intake system.

Ed,

Yes you are right.There is no went hole on the tank but I completely opened it during my tests.

Cobra428,

Yes I get a small pop when I choke it.
As for the glow plug light,it is bright red at the begining but not after several attempts.

Thanks


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## cobra428 (Apr 6, 2010)

Hi serhat,
I just thought of something. When I fly my planes in the winter months I use liquid lighter fluid to prime the engine. Works like a charm on cold engines. Maybe you want to give it a shot

Tony


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## crankshafter (Apr 6, 2010)

Hi again serhat.
I see you are using gaskets between the valveblocks, that is good. But then it hits me scratch.gif oh:: do you have good sealing between the valveblock and the cyl.head? It come to my mind that I had some problem,and I made a small counterbore in the intake port at the cyl.head and used a small O-ring for sealing.
Just another 2cent ;D
CS.


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## Longboy (Apr 6, 2010)

..............Remove the lower O-ring from piston. Double check the exhaust valve timing. Closed by TDC. Every attached item to the axle must be tight. Your carb is the right size and distance from valve block. I'm not familiar with glow operation but with spark ignition 1-1/2 turns on the mixture and a cracked open throttle work. If you get some pops or signs of life, the valve block gaskets and valve sealing are fine. Mechanical issues with these small engines..........if it doesn't turn over smoothly with the plug removed, can mimic a carb problem in setting its needle valves when trying to start. If it runs for a few seconds and just dies and you didn't touch it, it could be mechanical. The can-o-worms here is it can feel nice when just fingering the flywheel over. But at start-up and it goes to 1000RPM, things the motor doesn't like compound instantly and it stalls just as fast. I believe true carb problems relate to fuel delivery venting and manifold sealing that affect the vacuum signal.............Back to mechanical problems, your piston and O-ring should move easily in and out of the bore by hand holding the connecting rod with glow plug removed. If it feels like it dragging thru the bore to you , engine ain't gonna like it! :-\    Dave.


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## Ed T (Apr 6, 2010)

If the glow plug is not glowing brightly, it isn't likely to work. Most glow plugs are designed for 1.5 volt operation and do ok with the 1.2 nominal of NiCad cells. The lower internal resistance of the NiCad helps to reduce the voltage drop at high drains and the behavior is similar to a 1.5 volt dry cell. It's difficult to find large 1.5 volt dry cells any more. They were quite common 50 years ago. You can find them, but they tend to be expensive. What I have done in the past is wire up 4 Alkaline "D" cells in PARALLEL to make a nice, fat 1.5 volt dry cell battery.If you wire them in series, your glow plug will have brilliant, but brief career. This will probably make your glow plug happier and it sounds like it needs to be happier.


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## cobra428 (Apr 6, 2010)

Their still out there

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXL368&P=ML

Tony


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## Ed T (Apr 6, 2010)

Yes, they're still out there, but I'm guessing the shipping to Istanbul would be slow and expensive. Maybe they have them at the LHS, not sure.


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## cobra428 (Apr 6, 2010)

Your right Ed T
I sometimes forget that the people here are from everywhere.

Tony


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## serhat (Apr 17, 2010)

Hello,

I could not find that battery from the local market and did not order it also from tower hobbies as they usually do not accept international shipment for batteries,paints etc.....
Anyway,I have installed an o-ring between the cylinder head and the manifold as suggested and of course,it increased the intake capacity.
NOW THE GOOD NEWS.
It works.
But only for few seconds and then it stops (even I leave the battery on the glow plug) and does not work again. When I leave it for half an hour and charge the battery at the same time,it works again for few seconds and stops.

Why!!!!!!

I will try to take a video and share it with you tomorrow.


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## serhat (Apr 20, 2010)

Hello,
Here is the video
engine runs for a few seconds than it stops.
it does not start on the consequent trials.

waiting your comments. 

View attachment Benzinli Motor.m4v


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## Brian Rupnow (Apr 20, 2010)

Serhat---I just finished my webster build, and it runs very good, with conventional ignition ponts and a 12 volt coil with a sparkplug. You might find it a really big help if you made up an adapter for your electric drill like I did (I show a picture in my thread). This will really be a big help in getting the engine started.---Brian
http://www.homemodelenginemachinist.com/index.php?topic=8388.0


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## bearcar1 (Apr 20, 2010)

After watching your video Serhat and listening to your symptoms of the engine dying and not starting again until the battery has been charged, leads me to wonder whether or not the plug is remaining lit for but just a few brief seconds and the extinguishes itself when the battery voltage drops off. Do you have a means of supplying a voltage to the plug other than by using a battery? An appropriately sized power supply for instance. I'm just wondering if the battery isn't being drained of power in short order and the plug cannot stay lit. When you charge the battery back up it will last for only but a few brief moments and then the process begins again. Also, if I am not mistaken, there is what appears to be a mist of fuel being ejected on first start-up. I have watched the video several times and that is the impression I get each time. Keep after it, you are very close and I would love to see it run unassisted (as I am certain you do as well )

BC1
Jim


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## serhat (Apr 21, 2010)

Hi,

Brian,
I'll do that adaptor.

Jim,

You are right.
Batterry voltage is dropping quickly.So I will purchase a new glow plug battery (maybe 1,5V instead of 1,2V if I can find) and try again.
What I do not understand is that after a few seconds run,it should continue running even I take out the charger.What do you think?
I also do not understand why the fuel is ejected on first start-up.I carefully checked the intake and exhaust timing several times and also sure about the perfect closing of the valves.

Serhat


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## bearcar1 (Apr 21, 2010)

Good morning Serhat, I apologize for the misleading statement I made previously regarding the voltage dropping off, what I was thinking (and not being very clear verbally) was that the current capacity (milliamp hour) of your battery cell was not sufficient to keep the plug lit for more than a brief period of time. Like a flashlight when the batteries are dying. A voltage source that has a very high MAH capacity at a 1.2-1.5volts is in order. If you are electronically inclined or know of someone that is, perhaps a voltage converter/regulator could be assembled and then use a 6volt wet cell for the input power source. I'm just throwing out some ideas here. As far as the fuel being ejected, that is a bit of a mystery but it too could be compounding the engine running problem by literally 'putting out the fire'. Like tossing bucket of water on a burning piece of wood, so is the excess fuel acting upon the glowplug. Most likely though, I think that if you can obtain a power source that will sustain the plug for several minutes you will be in business. Once the engine is to the point of continuous running, then getting it to stay running after removing the battery voltage can be addressed. It may be that a constant power source will be required for continuous running.

BC1
Jim


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## serhat (Apr 22, 2010)

Hi,

I've got two 2,2 amp (1,2V) batteries installed on the glow-plug charger.
so it is 4.4 amp brand new battery.
Lets see what happens.


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## RickA (May 1, 2010)

Hi, I am brand new to this, and this is my first post, so please forgive me if this isn't right, but I just wanted to say thank you to all who were involved with helping someone who had build a Webster engine and couldn't get it to work. I just completed my Webster yesterday and today, I was excited to put the fuel in, in anticipation of seeing it run, but it just wouldn't. I had checked the piston for compression and it seemed adequate, and it freely moved back and forth in the cylinder. I had good spark, and I rechecked and made small tweaks to the carburetor and to the timing of the ignition and exhaust valve and nothing worked. On the forum, someone made mention of the spring that held the intake valve closed, and that made me think about my own which was slightly compressed in the rest position. I was able to cut off about .1 of the height, which still left a tiny amount of compression at rest. That was it! My engine took off on the first try and I am now a happy camper. I am surprised at how sensitive the engine is to such a small adjustment. Thanks guys!


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## Maryak (May 2, 2010)

RickA,

Glad our team helped.

Welcome to our forum. wEc1

Please post a bit about yourself in our welcome section.

Best Regards
Bob


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## Blogwitch (May 2, 2010)

Has anyone else tried this engine with a glow plug? It just might be that the internal layout of the cylinder head won't allow it to run for any length of time.

It might be that the direction of the fuel entry is straight onto the glow tip, in which case, once the engine started to fire and run, the fuel hitting it just might put it out, no matter how much battery power you feed to it.

My dealings have always been that the temp and compression in the cylinder has to be enough to keep the platinum wire glowing thru a catalytic process after the battery is disconnected.

Some of my glow engines required them to run for a while before that critical moment is reached, otherwise the charge of cold fuel going in extinguished the glow.

Have you tried a higher nitro mix, or a plug with a heat bar across the tip to try to retain some heat, or a shorter plug, so that it doesn't protrude into the cylinder so much, to try to protect the glo tip from any cooling fuel? 

Try a 5% mix of petrol in the fuel, that was used as an old trick when nitro wasn't available over here. Don't mix up a whole batch, just say 1/4 of a tank, just in case it doesn't work for you.

If glo plug running hasn't been done before, then you have no means of knowing what will eventually be required to get it to run, if ever.


Bogs


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## zeeprogrammer (May 2, 2010)

Welcome to the forum RickA.
Congratulations on your engine!
I echo the request for pics (and video).


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## serhat (May 3, 2010)

Hi RickA,

Welcome.

Bogstandart,

I have decided to choose the glow plug version after reading the notes of Joe Webster.
He says that the first few runs were too short but does not mention about any problem with glow plug version.
However,I agree with you on the cooling factor of the fuel on the glow plug.
I will add some gasoline ,as you advised, and see if it make any difference.

Brgds


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## NickG (May 4, 2010)

Serhat,

Am afraid I can't give any advice, not experienced at this but am sure this post will be of help when I get to that stage of building my first i.c. engine.

Hope you get it sorted quick, you can't be far away.

Nick


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## serhat (May 4, 2010)

Hello,

Finally it works much better now.It runs almost 30 seconds. :big:
I think with a fine tuning and some modifications on the fuel tank,it will run continiously.
What did I change for a better result?
Here are some important hints for those who want to build a webster with glow plug version.
1- A powerful glow plug batterry is a must.I have used 4.4 Amp batterry.
2- Some pressure is needed on the fuel tank.There is no pressure tube on webster engine that comes from the exhaust tube.So I am planning to raise the level of the tank and even use a bigger one.
3- This is the most important point,
  The tappet on the rocker arm should be a tight fit as it may be effected by vibration and causes a change on the timing.Unfortunately I have noticed this after so many days.

I will add the video,hopefully this weekend,and let you see the final result

Brgds


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## SAM in LA (May 4, 2010)

RickA,

I looks like persiverance is paying off.

I'm looking forward to seeing your engine run.

SAM


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## Cedge (May 4, 2010)

Serhat
I'm certainly no expert on IC engines, but when I began trying to run my Victorian for the first time, I enlisted one who gave me some advice I thought was too simple to make a difference. His advice was to keep plenty of oil in the cylinder to help seal the O-rings to the wall. That one small piece of advice proved to be invaluable to getting mine to run. I added a drop of oil into the cylinder before trying to start it and the compression level jumped by a significant amount. The additional compression would actutally take the flywheel out of my hand when I spun it. The engine started right up and ran for over an hour. Just another thought for you to consider....

Steve


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## bearcar1 (May 4, 2010)

Serhat, I am very glad to hear of your success at getting your Webster to run. I would not have imagined the tank having to be pressurized in your application but suppose that the engine was marginal in vacuum to reliably draw enough fuel to run. The larger battery was fairly evident but nonetheless, I am delighted you have solved the mystery. I am looking forward to seeing the video of continuos running ;D


BC1
Jim


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## serhat (May 6, 2010)

Hello,

Here is a short video.I could only captured the last few seconds.
A better one will follow on Sunday.

Let me know if you see something abnormal on its running.

Brgds 

View attachment DSCN2517.AVI


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## Brian Rupnow (May 6, 2010)

Serhat---Congratulations!!!! Your engine seems to run just fine. I am sure that you are closing in on whatever the problems were. Looks very clean and professional too.----Brian


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