Maybe one of the very small idle circuts in carb are clogged? Does the engine have a fuel pump, if it does maybe it doesn't pump well enough at a low idle. I don't have much experience with Tec engines so I can only take a guess.
Yes it does have a fuel pump, I never thought of this until now but there was a different kind of fuel pump installed on the one carb, I just swapped it over to the original one that came with the tractor but I will try and use the other one to see what happens...Thanks
If it is back firing through he carb I would think it is either a timing issue or a bad or loose valve seat. Have you pulled the head yet?
I have not pulled the head and would like to leave that as a last resort because it is a really in depth job...Thanks
I have had the same problem with my carb ... there is a clog in the low speed circuit and Normally you can't get it cleaned and for the Non reusable emulsion tube if you chuck it up in a drill you can turn it (like in a lathe) use a file to cut a V or a U into the spot where there is a small hole My suggestion if find another carb .. unless you can get it clean (VERY difficult on a lmh) for the reason they use Very small circuits...
(picture of modified tube)
Sounds like a possibility, I would love to get another one instead though....Thanks
So, if you have a 1983 Bolens H16x1, then you should have a OH160-170089A engine. The OH140 was used on the H14XL. If you've been buying carb kits for the OH140, that might be part of your problem. And yes, the parts list shows a fuel pump.
Edit: P.S. I vote timing. Two carbs with the same failure is to coincidental for me. Fire out the carb says ignition prior to TDC. Although, a sticking intake valve would have similar results, but it would be hard to get a compression reading of 173. Flywheel key is where I'd start.
You are correct it is infact an oh160, that is a misprint on my part, As far as the flywheel key goes, it would have to be a last resort to check that as the engine would need to be removed....Thanks
At first, it sounds like your carburetor is too lean. A similar thing happened on a Gravely L I was working on, but a Zenith carburetor. It carry on like a pile driver unless it was blowing away at 2500+ RPM. I had two problems, there: adjustments too lean, and a bad idle needle that had gotten bent.
Is the throttle shaft good? Gasket to block/manifold or air filter? Air filter itself? Air leaks will ruin your adjustments at low (er) speeds.
You've got good compression, and we'll assume that the carburetor is spotless. What about the spark? Bad spark will cause the motor to run poorly. Have you chucked in a new spark plug just to test? The OH140 had that huge solid state ignition, right? so no condenser and points.
By the way, not to market, but if you need the jet that 8tyman was showing, I've got a few NOS #30355 Walbro jets that need a home as well as other Walbro parts. I also have a NOS solid state marked "used" that you could have to try if you want to dig that far in.
Both carbs I have tried had new gaskets installed in the carb as well as by the intake but only on the outside of it, throttle shafts are fine, i was spraying around the carb with starting fluid as well as near the gaskets where the carb mounts by the intake and no increase in speed, or change in the roughness of the engine running, I have tried different spark plugs as well, as for the NOS parts you have, I would like to buy 2 new emulson tubes and 2 new carb kits for these carbs again, can you send me a PM on the prices of those items please, THANKS
First thing I am going to do is make a video of how this runs before I tear into anything else, I am going to make a series on this that way if we can figure it out maybe it will help others as well. Thanks for all the help so far and I will be giving updates along the way
Edited by Nascar3244888, March 19, 2013 - 08:56 AM.