394xp compression question

[Trent Curtis]

So here's what I've learned-

Set the low idle using a tac, then throw the tac away.

The 394 isn't gna do anything close to "specs" RPM wise. To run where I can get a nice 4 stroke that cleans up in the cut I need to be like 11,300.
Any more than that and I'm leaning out.

It pulls like crazy- not smoking and a nice plug color.

That's it- I'm done chasing the 12,500 spec book. 11,300 is where she's gna live.

#rookie lesson 1

 

[Trent Curtis]

So with that I close my thread--- thank you all for the help. This chainsaw mechanic thing is a lot of fun, but it has truly been humbling!!!

She's back together and waiting for some big trees.

PS- notice the sticker! They sent me the wrong one, 394 is on back order.
So until the new sticker arrives..... 395 it is!!

 

[decableguy2000]

Where and which decals did you replace?

 

[jmssaws]

Ported this one last week,stock it was 155lb.
It's not stock in this video,tuned at 13.5k
With a 50" 404 full comp and a huge 404 8pin. Gotta love a 394

 

[jmssaws]

It's at 14.2k in this video. They can spin pretty fast.

 

[Trent Curtis]

Ported this one last week,stock it was 155lb.
It's not stock in this video,tuned at 13.5k
With a 50" 404 full comp and a huge 404 8pin. Gotta love a 394

Holy.... That thing is a beast!!!!!!

How many RPMs was it running before porting?

 

[jmssaws]

Holy.... That thing is a beast!!!!!!

How many RPMs was it running before porting?

I never started it.
It should turn 13 stock anyway.

 

[tomdcoker]

Not to hijack the thread, but the mention of a 394 reminds me that I have a good crankcase and some other parts. Mostly covers and carb. mounting parts. I don't need a P & C because I plan on using a new OEM. So if anyone has a junked 394 they will sell please, please message me, Tom

 

[MGoBlue]

394 is on back order. So until the new sticker arrives.....

Good luck with that!! They are NLA.

EDIT: I didn't hear any 4strokin' in either of your vids.

 

[Big_Wood]

i run them at 13 stock. 13.5 ported. work saw tunes. a properly tuned saw doesn't 4 stroke much at all when warm. it's only an indicator that you are in the safe zone. unfortunately guys rip themselves off by being VERY safe lol

 

[jmssaws]

My saws are tuned to a very light 4 stroke when warm.
If you can't hear it 4stroke in a video it's lean,I video saws everyday and it always sounds richer on video than in real life.

11k is slobbering fat and leaving a ton on the table.

I've noticed over the years that almost every saw I port when I check the tune it came with its always way fatter than it needs to be on the low.
It shouldn't tune 1 1/2 on the low and 1/2 on the high,your compensating with the high for a fat low.

The low is to fat because the la is screwed in to far,back the la out to just touching and set the idle close with the low and it will tune with even jets then.

The low side is where the power can be found.

 

[Trent Curtis]

Good luck with that!! They are NLA.

EDIT: I didn't hear any 4strokin' in either of your vids.

Exactly- I can't figure out how everybody is getting 12k out of these 394s.

I turned mine back to a nice 4 stroke... Cleaning up in the cut..... And I'm only 11,400. It pulls with great torque...... Just not that fast.

At 11,700 it lost the 4 stroke and was getting flat spots at WOT (lean).

Anyway..... As I said. Done chasing the RPM. I'll let her run where she's comfortable.

 

[Trent Curtis]

My saws are tuned to a very light 4 stroke when warm.
If you can't hear it 4stroke in a video it's lean,I video saws everyday and it always sounds richer on video than in real life.

11k is slobbering fat and leaving a ton on the table.

I've noticed over the years that almost every saw I port when I check the tune it came with its always way fatter than it needs to be on the low.
It shouldn't tune 1 1/2 on the low and 1/2 on the high,your compensating with the high for a fat low.

The low is to fat because the la is screwed in to far,back the la out to just touching and set the idle close with the low and it will tune with even jets then.

The low side is where the power can be found.

Hmmmmm- really good info! I'm gna check the idle screw tmrw. im guessing that's what LA stands for anyway.... And it makes sense

 

[MGoBlue]

Exactly- I can't figure out how everybody is getting 12k out of these 394s.

Mine does, in fact it's tuned a bit fat for milling and is still at 12,5 (last time I checked). It's nothing I "did", Just where the saw wants to be.
No biggie though, run the he'll out of it... let er eat!