Building a 290/390

[paragonbuilder]

It's alive!!

Where's the vids? [emoji12]


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[jake wells]

now that it runs you can send it to emu legs to port it.

 

[MustangMike]

It's alive!!

Vids or it don't count!

 

[Adirondackstihl]

I'll get one.....
Chillax

 

[drf256]

W/O putting a degree wheel on this thing, about how much distance was that?

Mike,

There's a tremendous amount of variation in the AM jugs. Because it's a clamshell, it's a PITA to time it the traditional way.

@David Young uses (IIRC) a program called torquesoft that converts distance to degrees of crank timing. This is a case where I'd certainly consider using it.

I wouldn't just raise them, you don't know what you've got. This series has one one of the most restictive mufflers I've ever encountered. Open that sucker up.

If you want a welded popup piston on the saw, say the word Mike. Just sent me the jug and piston.

 

[MustangMike]

I really appreciate that Al, but this one is just going to be a cheap little toy I want to play with myself.

That program sounds very interesting. Do you have a link?

Also, no harm in widening the intake & exhaust if they look like they could use it, correct?

 

[drf256]

http://torqsoft.net/

 

[paragonbuilder]

http://torqsoft.net/

This is what I use Mike.


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[MustangMike]

Thanks guys.

 

[David Young]

I really appreciate that Al, but this one is just going to be a cheap little toy I want to play with myself.

That program sounds very interesting. Do you have a link?

Also, no harm in widening the intake & exhaust if they look like they could use it, correct?

give me a shout if you need help using the program.

 

[MustangMike]

Thanks, I will.

 

[angelo c]

clams are very good examples of "when to use a 'pop-up' "

 

[Lightning Performance]

Dont waste ur time on exhaust port work. Remember the poor transfers. Whats's the point?...

Everyone already nailed it for ya.
Popup with work and/or lift trans/ angle them progresively
Widen intake exit
The muff= choked up
Air filter= as the man said
Ign timing is like Wtf? really... um OK lol

 

[Lightning Performance]

When I get bored and have time, should be dead by then, would like to make the transfer tunnels round to see if it adds volume to the runners and the case. Might work might just kill it due to low velocity transfer ports.
One way to know for sure.

my key board is fubar

 

[MustangMike]

Got all the parts today from China. Don't really have time to play with it right now, but I did check out the P&C. I'm no expert, but they look decent to me.

I think I'm just gonna do a muff mod and timing advance and put it together (gotta finish taking it apart first). It may be a bit, got several things on the schedule.

 

[MustangMike]

Jeremy, Hope you don't mind sharing this thread, but I did my muff mod today. I usually just screw the muff covers down on a 2 X 6 and work with them, but my 3" deck screws would go reach through this thing, so I just C Clamped it between two pieces of wood, worked well.

Of course I enlarged the opening on the cover like everyone does, but I also tried to remove that channel to give it more breathing room. After doing that, it took a lot of tweaking to get the borders to lie flush again. FYI, the Huztl muffler does not come with a screen, but it does weigh 3.1 oz less than the factory unit (not a lot, but I'll take 1/5th of a lb).

Instead of enlarging the existing holes and adding several smaller ones, I took the simple route and just drilled a new 1/2" hole right in the center.

That should let it breath a bit better! Likely will not get to touch this project again till Monday, got stuff planned.

 

[MustangMike]

Had some more time to work on it today, and it is all ripped down and the engine is apart. Luckily my brother stopped by, he has hands like vice grips, so he put channel locks on the stud while I held the motor and we got it out.

Discovered there is no tank vent, so I ordered one of them.

Compared the AM cylinder to the OEM Mahle, and to tell you the truth, other than the much bigger piston, they are very similar, and the AM may even have better ports. Don't know what the squish will be, but the combustion chamber also looks a little smaller, and the plug has been moved just a bit.

Now I just got to clean everything up, change the piston, and put it back together.

Oh, the piston was scored slightly on both sides (intake & exhaust), I think maybe a bit of straight gas??? The bearings seem tight and very smooth.

I do have a few questions:

1) Do you use the Anaerobic Gasket Maker on these also? The stuff on there looks like rubber cement!
2) Do you put gasket material on the seals?

Thanks everyone!

 

[Adirondackstihl]

Had some more time to work on it today, and it is all ripped down and the engine is apart. Luckily my brother stopped by, he has hands like vice grips, so he put channel locks on the stud while I held the motor and we got it out.

Discovered there is no tank vent, so I ordered one of them.

Compared the AM cylinder to the OEM Mahle, and to tell you the truth, other than the much bigger piston, they are very similar, and the AM may even have better ports. Don't know what the squish will be, but the combustion chamber also looks a little smaller, and the plug has been moved just a bit.

Now I just got to clean everything up, change the piston, and put it back together.

Oh, the piston was scored slightly on both sides (intake & exhaust), I think maybe a bit of straight gas??? The bearings seem tight and very smooth.

I do have a few questions:

1) Do you use the Anaerobic Gasket Maker on these also? The stuff on there looks like rubber cement!
2) Do you put gasket material on the seals?

Thanks everyone!

Do NOT use 518 on these.
Use Dirko or Yamabond.

Yes.
Sealant on the OD of the seals.
All around the perimeter of the pan

 

[CrufflerJJ]

Do NOT use 518 on these.
Use Dirko or Yamabond.

Yes.
Sealant on the OD of the seals.
All around the perimeter of the pan

Do you NOT use 518 on these because it results in leaks around the bearing seals?

If so, I just ran into that issue with my Mighty Husqvarna 136. I guess the seal/case gap was too big to allow the sealer to cure. The original seal was leaking around the crankshaft on the flywheel side, so I installed replacement bearings/seals, and tried to seal it with Permatex 51813 ( = Loctite 518). I ended up with a leak at the seal/case interface. I've got it tore down again & plan to reseal it with Yamabond 4 once my Caber ring arrives from the Greek seller on eBay.

 

[Lightning Performance]

Make sure all the intake parts are in place. If the inner or outer steel rings are missing the intakes leak bad on 1127 series. They suck air at WOT. Real PIA to try and tune the high. I find it in used saws with extended WOT lean issues. They usually miss putting back in the inner ring behind the carb. Makes for a short cut is OK but long cuts go lean running condition.