Continued engine problems with my 129
 

There were too many threads that started as a specific topic and migrated on to more general discussion, so I started this one for any possible continuation. A recent suggestion was to post a short youtube video showing how my engine is running. I'll gladly do this if it would be truly worthwhile.

To summarize my other recent threads - I have recently cleaned the carb, replaced points, condenser, coil, and plug in an attempt to get the engine running better. Of late there has been a loss of power especially during mowing. Following the installation of the new parts, things are no better. Both leaner and richer carb adjustments did not help either. The tractor did not even have enough power to get from partway down the yard back up to my garage.

In short, I highly suspect a rebuild is in order. I can't imagine what else to try at this point. The engine is 40+ years old - has been overhauled once (probably at least 20 years ago) but I'm not certain what all was done at that time.

Any further suggestions welcomed, but right now I'm leaning towards contacting this Kustom Lawn and Garden business to obtain a short block.

Thanks to all who followed and posted to my previous threads.

I suggest loading up the tractor and bringing it to me. Not to offend but with your limited skill set you could easily be over looking something simple and there could be a bunch of different reason for your condition that would take use forever to talk you through. I've bought plenty of Cub's over the years that the seller thought needed rebuilt but the reality was that all it needed was an experienced mechanic. Unless it smokes like a freight train I doubt it needs a rebuild.

Tim....LOL about 'smoking like a freight train'. Actually, it smokes VERY little. I see a puff now and then when making turns or using more throttle, but it's not like I see any sort of constant blue smoke. Not at all. It does, however, go through a good amount of oil. And when it's running well - like after an hour or so after I start mowing - I don't notice any problems at all. But, since putting on the new electrical components, things are surely much worse.

I appreciate your offer greatly, but since my brother is also a mechanic, has a shop, and has just expressed a willingness to trailer it there (only about 30 minutes from me) to check it out, I believe I'll go that route.

One thing I forgot to ask in all the recent posts and threads, however, is: Can you effectively check the compression on these with a gauge, being that the ACR system is operating? I asked my IH service guy and he said that you can come up with a number but that, due to the exhaust valve being partially held open, you can't get an accurate reading. Wouldn't you have to either run the engine backwards and/or disconnect the ACR springs?

Also...two more items...1) the condition of the battery is questionable. It's 6 years old. Once the engine is running, could inadequate voltage associated with the battery be contributing to poor engine performance? 2) When I try to start it and pull the choke, sometimes it barely wants to crank at all. It cranks better with the choke pushed in. Makes no sense (?)

Is your brother a car mechanic or a small engine mechanic? I would let Tim take a crack at it since he offered. It may be something simple that he has seen before.

My brother does both auto and small engines. Plus one of his mechanics does lawn mowers and small engines on his own time. Tim is 3.5 hours away from me for one thing. And, I don't even have a trailer to be able to take it anywhere.

I think if you take a video and post it and do some real close ups to everything you changed, go slowly with the camera, we might be able to figure it out. However, it sounds like your brother and other guy are close so let us know

I will do that. We've had alot of rain today so I'm going to have to mow again soon (the whole summer has gone that way), so I'm chomping at the bit here to get this thing going again. I'm going to re-time using a light. Something just doesn't seem right in that the piston is well on the way back down before the S appears in the flywheel window, and it's even farther down by the time the T appears. Should that be the case? If I'm correct, the points appear to be open during the entire intake and compression stroke. I just wonder if things are out-of-whack between the cam and crankshafts. I did have the front pulley off awhile back (had a thread going about taking that off) and seem to recall there is only one way to put it back on - the one set screw going against the key. IF, however, I put the flywheel on at the wrong place (is that even possible to do?), then of course the S and T marks would not correspond to when the points open.

Did I hear you right?
 

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You say the piston is on the way down before the timing mark is visable? I don't think thats right at all. That would make you way late in timing. If I understand correctly the S mark should be before the piston reaches the top of stroke, and the T mark should be visable when the piston is at top Dead Center.

Gary - yeah, you heard me right. I've rolled the flywheel over and over to make sure. That's what I mean when I say that something seems way off. My piston is at the top long before the S appears in the window. And yet it appears that the points start closing right as the power stroke begins - so the points must be staying open a long time as I mentioned. The thing is, I didn't do anything that would change the relationship between when the points open with respect to the rest of the engine. So if the timing is way off, it must have been that way for a long time. No way to be sure until I use a test light I suppose. Right now I have a .020 gap set where the points are open at their widest. I paid more attention to that then where the points were with respect to the flywheel marks. This all feels like a puzzle for which I don't seem to have all the pieces, though in my case I suppose I have them all but aren't sure where they all go...and now please no jokes about my not having all my marbles LOL :biggrin2:

And to make sure, you are rolling the engine counter clockwise as looking at it from the front of the tractor?