Stihl 029 - Aftermarket rebuild troubles

[TheManOfStihl]

My dad's 029 was getting low on compression due to a scuffed piston on the exhaust side. So it got hot I told him, no big deal. We will put a new cylinder and piston in and be back in business. We decided to go with a no name kit from Huztl, being on a budget, which arrived the other day. He bought this saw new around 1993 and we've never had major issues, so it's still the OEM piston and cylinder in it.

I pulled the saw apart, cleaned everything and installed the cylinder and piston. It rolled around by hand well, all seemed to be good. Assemble the entire saw, install spark plug, and give it a few test pulls. Yeah, it's got way better compression now, but it clangs when it spins over. Pulling it slow, you can feel a definite resistance at the top of the stroke.

This is a clamshell engine, there is no gasket for the pan, just sealant. What would cause this? I reused the crankshaft, no play in the bearings, new seals, and sealant on the pan. There should be no variation for squish in this setup, right? It sounds like the piston is hitting the top of the cylinder, but I can't see in there well enough to see what's going on.

Removing the spark plug does not solve the issue, and the spark plug is not damaged. It still clangs when rolling over with the plug removed. Has anyone had a similar experience? I'm not sure what to do, but don't really want to tear the whole thing back down. I know that I have to, though...

Thanks for any input you may have.

(PS - I know, I went aftermarket, I get what I paid for. But I've used a handful of P&C's from Huztl with no issues other than this one. This is my first P&C issue.)

 

[Onan18]

I ran into a similar issue with a Meteor kit for a MS260, turns out they were not bored deep enough. If you are handy with a lathe you could always cut the squish band for more clearance.

Joe

 

[TheManOfStihl]

Thanks Joe. That's about what I expected. It's either got to be the piston being a little too tall or the cylinder too shallow. I guess I didn't set the pistons side be side to verify height, nor did I depth check the cylinder against the OEM cylinder that I removed. Honestly never gave it a thought, but you know I will now!

I put a Huztl P&C in an MS200T that cut like no other with zero issues last year. I also put together an MS440 with their kit, again with no problems, everything was great. I know everyone whines about Chinese parts, but when you are on a tight budget, you can't afford the OEM replacements. So I get what I get, and I got burned this time. I'll have to pull it back apart and measure things and see what I can do. Hope the old man didn't have any immediate plans for this saw...

 

[nstueve]

I would actually measure the squish before you get too ansy about anything. Clunking can come from a broken clutch pack or from not setting the gap on the coil.


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[drf255]

I would actually measure the squish before you get too ansy about anything. Clunking can come from a broken clutch pack or from not setting the gap on the coil.


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+1

Stick a piece of solder in there and see what you get. You just don't know till you tried.

Are you sure everything went back together right?

I've found that the AM kits usually have excessive squish so that they don't have failures and don't need to measure as well. Usually not too tight.

 

[anlrolfe]

Email them ASAP. Explain the problem and they will most likely send a replacement(on a slow boat). I had an issue w/ one of their MS-180 replacement engines having low compression that they took care of painlessly. Rings didn't want to seat.

 

[TheManOfStihl]

Thanks for the advice gentlemen. I will contact them and see what they can do, but also I will try and measure the squish, if I can find my solder. I will also check the coil air gap again, maybe remove it, as well as the clutch, to rule those out. What is a good squish for an 029?

I am fairly confident that I reassembled it properly, but I do make mistakes here and there. I'll try and check my work today.

I got a crankshaft in the mail the other day from Huztl that was poked through the side of the box and the flywheel side threads were dinked. I snapped a pic and sent to them, and they said right away they would send a replacement. At the very least, they do seem to have good customer service so far.

 

[nstueve]

I don't care what AM you use... You still need to put cabers rings in. Meteor is the only exception b/c cabers come in the kit. All the other aftermarket kits have junk rings as far as I'm concerned.


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[Stihlofadeal64]

take it back apart, you are going to anyway to look it over.
Something is not right inside. That way you can check everything back over.

 

[TheManOfStihl]

Ok, I got a chance to check things over. Yeah, I feel stupid. Thank you, nstueve, you hit it right on the nose. Flywheel magnet was hitting the coil leg. I swear I gapped it properly, but either the bolts were not tight enough or I messed up the gap. Sigh. It rolls over now like it should, no noise.

I was convinced it was the cylinder and piston, that was the only thing I had thought of last night as what the issue could be. I didn't think outside the box, and that's what it took. Thank you to all who replied, that's why I love this site, the wealth of knowledge here is amazing... especially for boneheads like me!

I will test run the saw shortly and see how it runs. Thanks again everyone for your input! False alarm.

 

[AndrewF]

Pretty happy ending though right?? You learn something new every time you make a mistake Thats why I'm so smart

 

[TheManOfStihl]

That's right. I've been making mistakes for years now, I've learned a lot, but I never stop learning, or making mistakes... whatever you call it!

Test ran for a few minutes, everything is great. Dialed in the carb, idles great. WOT sounds good too. I'm happy. I'll get it back to Dad and let him try it out. I was sweating all night about it, if I had to get another cylinder kit it would be two weeks out. He wouldn't have liked that at all. We're all good now!

 

[drf255]

Happy endings good.

 

[nstueve]

Nailed it! LOL!

I'm probably well into 200+ 029/290 farmboss builds. I can do a full rebuild in about 35-40mins now including muffler mod and limiter cap removal.

Now that it was a simple fix go pop a 3/8"-1/2" hole in the muffler and grind the front deflector cap open, remove limiters (if they are there). Redial carb to 1:1 open or close to it. Will run 10% better, guaranteed.


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[fearofpavement]

I had assembled a Huztl engine a week or two ago and there was interference with it rotating. It would turn about 350 degrees in both directions but I couldn't make a full revolution. Like you I was trying to figure out what the deal was and when I finally figured it out I felt very relieved. There was a little scrap of paper in the exhaust port (about 1/4" square or so. This created the problem. Removed that and all better.

 

[TheManOfStihl]

Well, when it was low on compression, it still started easy and ran great, it was just low on power. I did adjust the carb now and then, trying to keep up with it to keep it alive a little longer, and I did bore out the muffler. The square stamped in under the deflector was cut out completely. It was essentially straight through, and very loud, but it did make a noticeable difference. This time around I bought him a new muffler, and I was thinking what you are saying, drilling larger holes, but not punching the whole thing out this time. He complained about the noise lol! Limiters were never there, it's the original carb (as far and we can remember) so that's not an issue.

 

[TheManOfStihl]

I had assembled a Huztl engine a week or two ago and there was interference with it rotating. It would turn about 350 degrees in both directions but I couldn't make a full revolution. Like you I was trying to figure out what the deal was and when I finally figured it out I felt very relieved. There was a little scrap of paper in the exhaust port (about 1/4" square or so. This created the problem. Removed that and all better.

I'm glad to hear I am not alone! Good thing yours was just paper. My flywheel magnets seem fine, as well as the coil leg, but I'm sure it could have been bad. At least it was an easy fix for both of us. How does your Huztl engine run?

 

[nstueve]

3/8" down the center of the square spot is just about right with the screen still in. The center hole works better b/c it's a strait outlet for exhaust so it doesn't have to go through baffle. Still able to run without bleeding ears. You should both be wearing PPE anyway...


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[TheManOfStihl]

3/8" down the center of the square spot is just about right with the screen still in. The center hole works better b/c it's a strait outlet for exhaust so it doesn't have to go through baffle. Still able to run without bleeding ears. You should both be wearing PPE anyway...


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Uh oh. Busted.

Yeah, you are right. We don't always wear PPE but we should. I'll look into carving a hole in the new one tomorrow, help it breathe easier.
Does it count if the old man takes his hearing aid out before he cuts?

 

[fearofpavement]

[QUOTE=". How does your Huztl engine run?[/QUOTE]
....................................................................................
They run fine. I've built up a lot of them.