Building a 290/390

[huskihl]

The bolt/cylinder thread discrepancies are known problems on these. Some are fine, some are coarse self threading...

 

[stihl_head1982]

I'm feeling under the weather today, so progressing very slowly, but I did put the piston in the cylinder, put Dirko on all the surfaces, and bolted the engine into the chassis.

I will tell you that next time I use an AM cylinder, I will make sure the threads are clean before I put sealer on the engine. Ended up putting locktite on just for lubrication, an working the bolts back & forth until they punched through the case.

Need to take a break, but will continue cleaning & assembly later.

Use the bolts provided for the aftermarket cylinder kit (if they are provided).
The chinese do something different on those kits that I have bought lately. The early ones had self tapping clam shell sorta-like the OEM. Now they have the ones I've bought tapped out.
You could have encountered something different. Mine went together rather smoothly.

 

[Lightning Performance]

Maybe tonight I'll fire up the oven when the wife goes to bed

Your suppose to fire up her oven before she goes to bed

Has anyone ever tried to play with the upper portion of those transfers??? The boxy look of them just seems like it does not facilitate a smooth flow of the mix.

A slight transfer lift yields a better blow-down number. More RPM at the expense of grunt. The best gains IMO were widening and dropping the intake at the opening point (time/area) and an ignition timing bump. Everything else was a waste IMO and they just suck down fuel. Have not tried a popup yet. That could be a "Shaky Pete" with the 49mm jug. My favorite was the 310 with a lightened piston. It ran very well against the others and had far less heat to deal with than a 390. I would not do much with the timing on an 039. Checked some notes. The early 029 jug had the best stock timing numbers but, they are not consistent enough to give numbers on.

Remember guys and gals this saw was designed to be beaten to death and put up wet. They new right from the git go it had to be tough cause stupid would be running it

 

[Chainsaw Jim]

The 1st one I ever done needed vice grips right to the end.

My very first experience with one was the same way. A person can easily get caught up in it and go into a rage during the last few turns when they start thinking of the hamfist that wasted an entire bottle of loctite on one nut. Lol

 

[CrufflerJJ]

My very first experience with one was the same way. A person can easily get caught up in it and go into a rage during the last few turns when they start thinking of the hamfist that wasted an entire bottle of loctite on one nut. Lol

Loctite RED, of course!

 

[MustangMike]

I was really feeling like crap yesterday, so I just worked on it a little here & there, but I got the tough stuff done. Mostly just took my little work bench and went out side, but also did a lot of it right off my lap. I put the cylinder upside down between my legs and it took 3 tries to get that piston to go in there, but it finally went!

I'm feeling a little better today, but not 100%.

I got the flywheel on, with a little timing advance, and converted the chain drive to a drum (w/bearing) I had from a 460, will be using 7 pin rim. The 460 drum bearing is far more substantial than the one that came on this saw.

Still have some parts on order, but I may just throw the carb on it later to see if she runs well. W/O my bar bolt, I will not be able to put it in the wood.

These things are more difficult to work on, but as long as you are not in a rush, it is sort of like just solving the puzzle. Took several tries to get the engine into the chassis, almost looked like it did not want to go!

They did not give me any new engine bolts with the P&C, but I have noticed that virtually all of the threads on the cylinder need to be cleaned up. Since I did not realize it in advance, I mostly just put some locktite on them and work them back & forth till they are in. Seems to be working.

Perhaps the black coating they put on the cylinder is what is mucking things up. I had to remove it from all of the mating surfaces. Used a little bit of sand paper followed with brake cleaner.

 

[MustangMike]

Well ... It's ALIVE!!!!

I thought I did all the hard stuff yesterday, but that is only because I'd never put one of these little B******* together before!

I thought I had figured out a good method of drilling a hole in the top cover for the decomp valve, but when the saw started spinning like a helicopter I realized things had not gone as planned. Gorilla Glue is helping me fix the top cover, and I finished shaping the hole with a razor knife.

And when I broke the metal end off of the kill switch wire, I had to break out the soldering stuff, but it is fixed!

The replacement bar bolts I ordered came today, but of course they are the wrong ones, so I will not be putting it in wood any time soon.

Also, the idle was very erratic at first, seemed to settle down some after some run time and adjusting. I think the carb may have sat for a long time and needs to be used a bit. Hopefully it will clean up on it's own. The saw did tach up nicely, run clean, and was 4 stroking, so that was all encouraging.

I considered putting the spare Huztl/Farmertech carb I have for the 044s on it, but when I pulled it out and looked at it, I was very disappointed. The first one I got through them said ZAMA on it, and worked very well. This one is a no name, has a lot of machine marks on the outside, the adjustment screws are very stiff, and idle screw is as big as a horse! That said, it looks like an 044 carb would go right on one of these things.

Since the carb on it is a Walbro, I'll leave it on and rebuild it if I need to.

Now if I can only get my replacement parts to come, still need a tank vent and the long bar bolt (they sent me the short ones).

I'm anxious to know how this thing will cut wood. It was an inexpensive project, but a heck of a lot of time, and a real learning curve. These Clamshell saws are just different!

 

[Terry Syd]

These Clamshell saws are just different!

And a pain to work on. They may be an inexpensive saw to rebuild and put back in service, but I hate working on them. I will never own another one.

 

[CrufflerJJ]

Congrats on the "birth" of your new baby saw!

 

[paragonbuilder]

Great job Mike! Looking forward to seeing some video and hearing your thoughts on it


Sent from my iPhone using Tapatalk

 

[huskihl]

Well ... It's ALIVE!!!!

I thought I did all the hard stuff yesterday, but that is only because I'd never put one of these little B******* together before!

I thought I had figured out a good method of drilling a hole in the top cover for the decomp valve, but when the saw started spinning like a helicopter I realized things had not gone as planned. Gorilla Glue is helping me fix the top cover, and I finished shaping the hole with a razor knife.

And when I broke the metal end off of the kill switch wire, I had to break out the soldering stuff, but it is fixed!

The replacement bar bolts I ordered came today, but of course they are the wrong ones, so I will not be putting it in wood any time soon.

Also, the idle was very erratic at first, seemed to settle down some after some run time and adjusting. I think the carb may have sat for a long time and needs to be used a bit. Hopefully it will clean up on it's own. The saw did tach up nicely, run clean, and was 4 stroking, so that was all encouraging.

I considered putting the spare Huztl/Farmertech carb I have for the 044s on it, but when I pulled it out and looked at it, I was very disappointed. The first one I got through them said ZAMA on it, and worked very well. This one is a no name, has a lot of machine marks on the outside, the adjustment screws are very stiff, and idle screw is as big as a horse! That said, it looks like an 044 carb would go right on one of these things.

Since the carb on it is a Walbro, I'll leave it on and rebuild it if I need to.

Now if I can only get my replacement parts to come, still need a tank vent and the long bar bolt (they sent me the short ones).

I'm anxious to know how this thing will cut wood. It was an inexpensive project, but a heck of a lot of time, and a real learning curve. These Clamshell saws are just different!

About swapping the 044 carb- the one on your 029/039 is probably bigger. Mine both were

 

[Adirondackstihl]

044/046/440/460/461 carbs are a direct fit on these chassis

 

[MustangMike]

Finally got all my parts in today, the bar-bolt & tank-vent finally came in. It was pouring cats & dogs when the stuff came, but I installed it anyway, and when I got a brief break in the raindrops I threw a B&C on it (it came on the MS440), adjusted the idle a bit, and put it to some wood.

Got the saw to idle smoothly with a little carb adjustment, finally, a big relief!!! It tachs up pretty nicely too, but when I put it in some wood it was clear the chain is in need of some sharpening! The wife called me for dinner, and the rain returned, so it will have to wait till another day, but I feel really good about getting it to idle and how well she tachs up.

Total of parts for the build including: muffler, air filter, decomp valve, impulse line, bar bolt, tank vent, cylinder, piston & seals were $60, shipped! I had an extra fuel filter on hand and a spare B&C from my MS440, and the clutch drum, bearing & 7 pin rim from a MS460. It pays to keep spare parts around, you never know when (or how) you may use them.

Doing a Clamshell took a lot of time, but I also look at it as an educational experience, I now know a bit about them, and they will not intimidate me.

I thank everyone who provided technical advice, especially Jeremy and Herman. W/O all of the great technical advice, I'm sure I would have made several blunders.

It is reassuring to proceed down a path armed with the advice of those who have already traveled on it. THANKS!!!!!

 

[MustangMike]

Almost forgot, I do have a question. Has anyone tried to use one of the 029 style tank vents on an 044??? Looks to me like it would work if you make the hose the right length. I even cut the hose to length to use it on the 029.

Thanks.

 

[MustangMike]

Sharpened the chain today (it is being converted to square file) and it cut much better. Only had some small Hard Maple to play with, but it went right through the Hard Maple, so it is doing OK.

Maybe I'll get to give it a real workout on Friday.

 

[MustangMike]

Hey, I can finally post some of the pics ... look at the size difference in the pistons!

 

[MustangMike]

Gave the saw a good workout today, it runs good. Has nice speed for small and medium size limbs, but when you start using a good amount of that 20" bar it is easy to slow her down. Likely the result of an open port cylinder and mediocre compression.