Continued engine problems with my 129

[three4rd]

Not sure if I mentioned this before, being that there have been so (more like too) many threads and posts lately about my Cub. But...when it runs it seems the governor is always chasing. The engine speed is erratic and unsteady. I'm guessing that this would have more to do with carburetion than timing? It all ties in with the loss of power I suppose. AND...I noticed last night that most of the head bolts weren't tight at all - so I tightened all of them up. At least I think these are the head bolts - about 6 of them right on top of the engine (?) Either way, I'm betting they shouldn't be anywhere near as loose as they were.

Just looked at the service manual after posting the above...There appear to be 9 head bolts. Some must be under engine shrouding. I should probably pull off what tin I need to and check the other 3 bolts (?) The 6 I tightened up were places where there were bolt holes in the shroud.

[Alvy]

Yes that's a big problem. Time to take the head off and flatten it, new head gasket after cleaning/decarbon the valves, top of the piston etc.

[three4rd]

Originally Posted by Alvy

Yes that's a big problem. Time to take the head off and flatten it, new head gasket after cleaning/decarbon the valves, too of the piston etc.

What is a big problem...that the bolts were loose? Or that my pictures indicate issues that need to be addressed? Not sure what you're referring to. I did not do any carbon scraping - was worried about screwing up the gasket. I was really tempted to at least scrape the carbon off the top of the piston but was just hesitant due to maybe getting dirt down inside the cylinder. Unless I'd actually take the valves out and do everything that should be done, I figure just doing some scraping really wouldn't make that much difference, would it?

[Alvy]

Originally Posted by three4rd

What is a big problem...that the bolts were loose? Or that my pictures indicate issues that need to be addressed? Not sure what you're referring to. I did not do any carbon scraping - was worried about screwing up the gasket. I was really tempted to at least scrape the carbon off the top of the piston but was just hesitant due to maybe getting dirt down inside the cylinder. Unless I'd actually take the valves out and do everything that should be done, I figure just doing some scraping really wouldn't make that much difference, would it?

Well I phrased it wrong. I meant that it definately needs to be addressed because loose head bolts will cause all of your symptoms as Jon said. You posted pictures after I posted. Just bring the piston to the top and clean away. Get the whole area super clean as well as clean and flatten the head. New gasket, get a torque wrench and follow the torque sequence.

Time to watch the body man extraordinaire video as well

http://www.onlycubcadets.net/forum/s...ad.php?t=45286

[three4rd]

I wonder if I tightened the bolts too much - guess I'll have to loosen one and try the torque wrench to 25-30 ft. lbs as called for just to see how tight it is. Then I can re-do them all. Already put it all back together as I said! No real big deal though to take off the shroud and get back in there. I wasn't planning on getting a new gasket. I believe it was replaced only 4 years ago. What I also didn't do is follow any tightening sequence...should have assumed there is one. So I guess I really should check it. Maybe the bolts weren't loose after all, since I've read that 25-30 ft. lbs is not all that tight. Have to check it again.

[DeltaCub]

Originally Posted by three4rd

I wonder if I tightened the bolts too much - guess I'll have to loosen one and try the torque wrench to 25-30 ft. lbs as called for. Already put it all back together as I said. I wasn't planning on getting a new gasket. I believe it was replaced only 4 years ago. What I also didn't do is follow any tightening sequence...should have assumed there is one. So I guess I really should check it. Maybe the bolts weren't loose after all, since I've read that 25-30 ft. lbs is not all that tight.

The torque specs and sequence are in the K Series manual. It is your friend!

[J-Mech]

Head gasket is leaking.
Engine is running lean.
It's burning oil.

You already screwed up putting it back together, because you didn't clean it, get a new gasket, or torque it. Please just take it to your bro. For crying out loud he offered to fix it, and he's not even far away. Calm down. Wait, and get it right the first time.

[J-Mech]

Originally Posted by three4rd

Not sure if I mentioned this before, being that there have been so (more like too) many threads and posts lately about my Cub. But...when it runs it seems the governor is always chasing. The engine speed is erratic and unsteady. I'm guessing that this would have more to do with carburetion than timing? It all ties in with the loss of power I suppose. AND...I noticed last night that most of the head bolts weren't tight at all - so I tightened all of them up. At least I think these are the head bolts - about 6 of them right on top of the engine (?) Either way, I'm betting they shouldn't be anywhere near as loose as they were.

Just looked at the service manual after posting the above...There appear to be 9 head bolts. Some must be under engine shrouding. I should probably pull off what tin I need to and check the other 3 bolts (?) The 6 I tightened up were places where there were bolt holes in the shroud.

Did you torque them with a torque wrench?

Loose head bolts may be part of your problem. That would make it have low compression, and burn oil.

[three4rd]

Did not torque...I could easily go back and do that. Actually, I got so intrigued once I had the shroud off and could access all the bolts that I decided to take off the head to see how things looked. It was fun and exciting - having never had it off before! Once I had it off, it made me want to keep going! I'd love to rip into the whole thing now after getting a small taste of it.

Anyway, I have no idea if this will be helpful or not to ascertain the condition, but here are some pics I took. Certainly the gasket looks ok to me, but let me know what you think. Piston and cylinder seem alright too.