Hybrid clonesaw 365 with a 390 topend - aka the "86'r from youtube"

[Ketchup]

Great work! Very excited to see a 95cc 372.

 

[upstateamish]

Me too! If it works, the next prototype will need some additonal case trenching on the clutch side to case match the transfers.

And when I pressure vac tested last night and had a small leak around the crank bushing, so I've pulled the seal and bushing out and did a small amount of 1184 around the base (as I don't have the overpriced o-ring)

more to come as more parts arrive.

 

[Ketchup]

Looking at 385/390, there’s no bushing. The oil gear just rides on the pump. Seems like that would overheat the gear, but it would eliminate the bushing/o-ring/seal problem. Could you do that with a tighter ID seal?

 

[upstateamish]

Yeah, I don't have an actual 385/390 to reference but from what I can tell in my research they changed their bearing style to move to an integrated seal (like the 562 series saws.)

Here's one I found:

NEW OEM HUSQVARNA 385 XP 390 XP JONSERED CS2186 CS2188 CRANKSHAFT BEARING —B55 | eBay

CS2186 (2005-03) Chain Saw. CS2186 (2007-01) Chain Saw. CS2186 (2009-05) Chain Saw. CS2186 EPA (2005-03) Chain Saw. CS2186 EPA (2007-01) Chain Saw. CS2186 EPA (2009-05) Chain Saw. CS2188 (2009-05) Chain Saw.

www.ebay.com

Which looks like it was originally seperate (seal/bearing)

385XP Husqvarna Professional Chain Saw Crankshaft Parts

But I *think* it changed from using something like this seperate type of seal that pressed in ?

Husqvarna Kettensäge | Motorsäge Radialdichtung

Radialdichtung für Husqvarna Motorsägen Ersetzt Artikel 503 26 02-10 | 503 18 45-01 Passend für: 455 E 455 E Rancher II 455 Rancher 455 Rancher II 460 461…

www.boerger-motorgeraete.de

Either way, to use the bearing for the 390, the case would need to be bored out to fit. We'll see how well I can get this to seal, I think it's close.

Maybe the integrated seal bearing approach is a task for the 4th prototype

 

[upstateamish]

Parts arrived over my lunch break! I installed the new seal and it is now holding pressure/vaccuum. So I started pulling the rest of the parts out to finish the build.

 

[upstateamish]

Alright. after searching through the bins for a bunch of random parts along the way... Got it together. I have a couple parts that still need to be ordered.

But first fire is a success!

Long form vid (skip to 45 seconds if you don't want to see me yarding away on it...)

- I didn't hear it when I was running it but I hear some knocking in the vid that I *think* (hope) is the air duct/deflector hitting... the flywheel... it was aftermarket didn't seem to sit flush and I was not sure how it would go.
- Carb is not tuned & the throttle cable was sticking open slightly. I've remediedt that but ran out of daylight.

Near the end of the vid I was getting some weird spitback firing issues that I assumed was carb related so after it it died a couple times I stopped so I could pull the muffler to see how the piston looked, check bolts (and now that I've listened to the vid, try and find the source of that knock)

Still seems to pull over ok and piston looks good with no scoring (yet)

 

[upstateamish]

ok, I believe I found the source of that knock. I sheared the timing key on the flywheel when the lock washer came loose.


I happen to have a spare (as I'll be doing prototype 4) so I swapped the good one on. I figure this one can be used later for adjusting timing if I need to.

Also added the deflector on the muffler to open it up like the others I have.

With those in place (and throttle linkage freed up) it seems to be running decent. I know it still needs a little carb tweaking (to stop it from dying out at idle) but it's raining so this is all I'll plan to do at the moment.

I'm pretty excited to have things to this point