Cylinder bolts won't tighten after 029 to 039 conversion

[Scottie68]

Bought a Hyway 49mm short block for my 029 Super from SawAgain since my original bearings were shot and had a little scoring on piston. I've tried the original cylinder bolts and the set that came with the new cylinder and they all thread in but won't tighten. Anyone ever heard of this? Solutions?

 

[Kenskip1]

Can you get nuts on the top of the bolts?

 

[Scottie68]

No, not enough room.

 

[Kenskip1]

How about from the top down?

 

[buzz sawyer]

Not sure what you mean by "won't tighten". Do you mean the bolts keep turning in the threaded hole or they don't pull the cylinder down tight? Maybe a photo would help?

 

[HarleyT]

Were the hole pre-threaded?
Are the threads the same?

The originals should have been left out of the project.

 

[old guy]

Are they bottoming in the hole?, shorten em.

 

[Scottie68]

The bolts can only go in from the bottom and no room for a nut on top of bolts. The holes were pre threaded and I was told by SawAgain to use my original bolts, which have the same threads as the bolts that came with new cylinder. I called SawAgain to ask why I couldn't use the new bolts - they said they have seen them break off before getting tight. When I mentioned that the original bolts weren't tightening but the new bolts seemed to work fine, SawAgain said go ahead and use the new bolts. I used the new bolts because they seemed to tighten initially and the original set didn't. Both sets of bolts thread into the cylinder all the way and the new bolts initially seemed to tighten but after getting everything back together and trying to start the saw, the bolts loosened up. Tried to re-tighten and now they all just spin and won't cinch down.

 

[holeycow]

Did you manage to completely strip-out all 4 bolts or their threaded holes?!!

If so,

You get the trophy for extreme hamfistedness of the highest order!



I am just trying to lighten what might be a grave situation..sorry. We have all wrecked stuff inadvertently.

 

[Scottie68]

I didn't overtighten the bolts. Threads are fine on all the bolts. Rather, I would say it was a poor thread job on the new cylinder. I chose to get the Hyway cylinder because of the recommendations on a previous thread on this forum. I'm just looking to see if anyone else has experienced similar issues or has a good solution.

 

[Mad Professor]

What do the threads in the cylinder look like? Intact or stripped?

I know it's a 029/039 so you don't want to spend a lot, but my solution is I don't purchase parts made with "Chinesium" . The older I get, time becomes more precious, and I'd rather be running a saw, hunting, or fishing, than "fixing" new parts.

 

[TRTermite]

I am thinking of doing this 029 to 039/390 and am watching/reading for any and all info on it.
I Was Thinking of Hiway for my conversion HL Supply here was out of stock so I WAS going to wait..May have to reconsider,, pending how you and your saw fares through this.. I will be watching and hope things work out well for ya

 

[Scottie68]

I'd have to pull the cylinder to get a look at the threads but I'm confident they are intact. When I initially installed the bolts and two of the original bolts wouldn't tighten up, I took a good look at the threads then and they looked ok.

I wouldn't recommend the Hyway 49 mm short block at this point. In addition to the cylinder bolt problem, the hole for the ground screw wasn't deep enough and I had to drill and tap it. We'll see what SawAgain has to say tomorrow.

 

[67L36Driver]

I’ll suggest 6mm Helicoil the cylinder and use socket head machine screws with a flat washer.

The OEM self tapping screws are a one time shot at best. I don’t use them in the aftermarket cylinders.

 

[Boredrob]

I'm just looking to see if anyone else has experienced similar issues or has a good solution.

I also recently used my last kit from them. Also from sawagain. (I didn't contact them at all about my issues and their shipping was quick and packed well) The sealed engine wasn't close to sealed. Luckily I checked it first and redid the crank seals. Worst part was removing the red sealer they used. Maybe dirko. I had to use the original stihl bottom case half because the new one had a bad fit. My cylinder also stripped the clamshell bolts. 2 of them stripped using a T27 screwdriver so over tightening wasnt the problem. The other two held but started to stripped with 30 or so inch/lbs with my 1/4 drive torque wrench.

I wouldn't recommend the Hyway 49 mm short block at this point. In addition to the cylinder bolt problem, the hole for the ground screw wasn't deep enough

Nor would I for the reasons stated above mostly. My ground bolt was also tapped with the wrong thread. I know because I used a bolt that worked fine. I forgot the pitch but it was metric. The cylinder walls and piston seemed good quality though. I'd try to use a cheaper Chinese engine next time personally. I wasnt impressed for the price.

So yeah, you aren't alone. I had the same issues. Did you check yours for seal?

 

[Scottie68]

Thanks for the input. Good to have confirmation I'm not going crazy. I would recommend everyone let SawAgain know when there are issues. Otherwise there is no chance of the issues getting resolved for future purchasers.

No, I havent checked for seal but I will if I end up being stuck with this cylinder.

 

[Boredrob]

One side of mine had terrible fit. No way it would seal. Oddly enough that side did seal and the other didn't.

I didn't contact them because I resealed their engine. And then stripped the cylinder. If I did send it back I'd have been out my yamabond and seals, time etc. plus had to reclean the other bottom. Still your correct I should probably tell them but I kind of hoped it was a fluke

 

[buzz sawyer]

Well this is getting confusing. If the bolts won't tighten in the threaded holes in the cylinder and the bolts are the same size as the OEM and have good threads and the holes in the cylinder have good threads, then either the threaded holes in the cylinder are larger than the bolts, or the threaded areas in the cylinder holes are short and the bolt threads are winding in past the threaded areas in the cylinder holes.

 

[Scottie68]

Either way, the bottom line is the Hyway cylinder is crap. We'll find out tomorrow how SawAgain's customer service is.

 

[Boredrob]

Well this is getting confusing

Idk about the op, but in my case the holes stripped. The metal is clearly soft or they used too much torque when putting the bolts in for shipping (they ship "sealed" with spacers on the bolts) . I used the new bolt in the first hole at least and at some point started using the stihl ones. 2 of 4 stripped with a nut driver. The other two were stripping around 30 inch lbs. The new bolts and the stihl bolts are the same thread pitch in my case. And the bolts are threaded the same length. The threads on neither bolt ever got pulled or marred. Just the cylinder