I have a 3W-150 TOC engine. When first attempts to start failed to get the engine running properly I could see that no fuel could be drawn into the carb. I rebuilt the carb and replaced the reed block gaskets. I figured I had a vacum leak somewhere in that area and I was right.Now it draws fuel ok and will start on 3/4 throttle and run at 6000rpm on a 32/10 carbon fiber prop wide open but when I try and start it in idle or just above idle it just starts and stops. Right now I have the low end set at 2and 1/4 open and will try and start again tomorrow. It is a Tilliston carb. Does the high end have anything to do with the midrange? What settings are the correct ones for this carb. I also hear that if the engine dies after chocking it might be to lean and it could be the ignition. How can you check the ign to see if it is working properly? Anyone have the correct settings for this engine and carb setup? What settings should I begin with?
I have been trying to work this problem now for a few weeks and I just can't seem to get anywhere. Any advice with my problem would be greatly appreciated. By the way the engine was used when I bought it.It is an older engine that has a 4.8 volt ignition. Great compression. Just will not run in mid range,even at half throttle or below.

Need Your Help,
S Mullis

i think you low speed needle has stoped up and may require a new carb now.

Same characteristics the butterly being 180* out will do..

Rick

When I rebuilt the carb the only thing I did not do was take out and replace the little silver plug in the carb. I really did not know what it was for and I could not figure out how to get the old one out and pop in the new one. Could this be one of my problems? I have the little lever for the needle flush with the housing now. It was above the housing so I tweaked it to level. I will try and run the engine tomorrow.
Thanks,
S Mullis

I checked the butterfly and it seems to be installed correctly, being the notch should be lined up with the holes on the low end needle screw. Correct? All holes seem to be free of debre and fuel runs freely. Any idea how the needles should be set on this carb?
Thanks,
S Mullis

had the carb sat for a while? 2 turns open will give you a good start on tuning the needles if you have a walbro carb....

It is a Tillitson carb,and yes it set for about a year and 1/2 before I finished my plane. I have rebuilt the carb and like i say, it will start great at 2/3 and full throttle but when I reduce power it just will not run at 1/2 or below. It sounds like it is just loading up. I did some work on it today and will try running it again tomorrow. I did download the manual from A/I and have been folowing the inst to the tee but to no avail.I will see what tomorrow brings. Thanks for your input.
S Mullis

Hi,

try an initial setting of 1 3/4 turns on the low speed needle and 1 turn on the high speed needle


Elson

if al those setting do not work do look at buying a new carb from a chain saw dealer on line, this will save u about 100.00 bucks over buying them from the 3w dealers. I had this happen one time and the low speed passages were varinshed up shut. Just basic cleaning the carb would not clean those tiny passages.....

If you decide to ge ta new carb, Call Ralph, He will give you the best deal around. I needed a carb for a 3W 150 a about 3 years ago and both 3W dealers wanted around $135.00.

I think list price on it is about $90.00 so I went a different rout.

Milton

carbs r about 225.00 now from the us 3w folks that is a walbro price.....

WoW

Then I would give Ralph a call for sure

Right after I got the price from the 3W dealers for mine I was at the Toledo show and got one from a another none 3W dealer for $45.00, Now I know I got a real good deal.

That is ridiculous getting over two times the list price for a product, It is worse than what a lot of the well known engine dealers get for there replacement ignitions.

yeah they got me once as i did not know about the chainsaw and lawn mover shops the big carbs like the 150cc are no joke in price. the 50cc carbs are nice and low around 30-50 bucks

That sounds great fellows. anyone know what site online I can order a carb? If I decide to go with Walbro carb anyone have any numbers on which carb I should buy that will work on the 150? I live in a real small town and we are limited on part stores here. In fact all we have is NAPA. Any phone numbers?I went to the lawn mower shop in a bigger town and checked on a Walbro WGA-7 carb and they said no one has one and I would haft to order one and it would take a month at $100.00 dollars. What other carbs will work. I mean can we crossreference and find a sutible replacement?
Thanks,
S Mullis

The carb that is on mine say's WGA7 and under that is 917

Call Ralph @ 928 635 2455

Web site www.rcignitions.com

If they are in stock he can have it shipped to you plus he might have a another model number that will work

Thanks for all the input, flyers. I did not get a chance to run the engine today but tomorrow for sure. I have the high set at 2and1/4 open and gonna start from 3/4 on the low and work my way from there on the low end to more open and see what kind of results I have and will let you all know more tomorrow nite. What can it hurt. If I can't get a reliable idle I can only assume I need a new carb as I have rebuilt the carb and installed new gaskets all around the reed blocks and intake. I did not over tighten the reed block mounts. I read on RCU you can warp them. I am getting fuel to the carb though and that is a good sign as I assume there is no leaks.
S Mullis

yeah that is what is on my 3w-150's also

Hi,

You are working the needles backward. The low needle feeds gas at all throttle plate positions and the high needle kicks in at mid-range and full throttle. Start with the initial needle settings of 1 3/4 to 2 turns on the low speed and 3/4 to one turn on the high speed.

Elson

put them both at 2 turns open the facotry setting at 2.25h and 1.5L on the low u will find 2 will be real close on the high depending of course

Well fellow flyers I have tried all your suggestions and even some other ones but to no avail will this engine run in mid or low or idle worth a hoot. I put in new reeds and I know it is pumping fuel. It runs great at high end but that is about all. I have come to the conclusion I haft to get a new carb. I put new gaskets all around and I know there is no leaks. I used permatex on all gaskets. I might have a crack in the carb somewhere because I see fuel dripping out around the carb from somewhere.The fuel inlet line is tight and I am using the right size tubing. I even pulled the plug out and checked all the holes again and installed a new plug. I guess it is just worn out and need a new one.
Any other suggestions from you fellows I might try before I invest in a carb and should I go with a Walbro or Tilliston. Tilliston is what is on there now.
Thanks,
Steve Mullis

Hello Steve I needed a new carb, tillitson, so I called Petersen, and was informed the tillitson was not in stock and would take a month to get one, so I ordered a Walbro wga-9, which is the replacement for the wga-7, per Peterson, think it was around $70. It will work on the 150. Petersen"s phone no. is-800-537-6212. Hope this helps.
Jack

sounds like a new carb is the ticket as your low to mid end has gotton varnished up i think

smullisTry Placing the metering needle arm back where it was to begin with and see how it runs.