Jonsered 670 champ intake leak

[davidwyby]

I’ve jacked with the carb screws enough I don’t think that’s it…and I think the neighbors are tired of it. But I might give it a shot. I started out 1.25 turns out and it seems to run best 1/8 turn leaner IIRC.

 

[Woodslasher]

I’ve jacked with the carb screws enough I don’t think that’s it…and I think the neighbors are tired of it. But I might give it a shot. I started out 1.25 turns out and it seems to run best 1/8 turn leaner IIRC.

Not the low mix, the idle speed screw. I think it’s marked T on the saw body.

 

[davidwyby]

Yeah I figured that out after I read it again…it seems to me like if it’s running right with the mix adjusted where it should be…

…but then maybe the throttle does need to be open more…and fatten up to slow it back down.

 

[Woodslasher]

Fyi, in 50 something degree temps my 272 ran almost perfectly on the same tune it had when you stopped by. I guess I don’t need to ever adjust the tune on my saws, I just need to run them in same the temps I tuned them in!

 

[David Young]

@Spike60 would you school us on the return line on the carb? My spare tank only has one fuel line port and a compressed brass vent.

Seal it off with solder. I fought with it for a lon g time on Matt halls 670.

 

[Funky sawman]

I remember something about the return line was to prevent vapor locking, as it kept fuel cycling through the carb to keep it cool

 

[Johnmn]

@davidwyby I have a solution, send me the 670 and I'll dispose of the troubled saw properly.

 

[davidwyby]

Seal it off with solder. I fought with it for a lon g time on Matt halls 670.

Interesting, maybe I’ll cap it and try it.

 

[davidwyby]

@davidwyby I have a solution, send me the 670 and I'll dispose of the troubled saw properly.

I’ll take offers, but the 630 goes with it

 

[Johnmn]

I’ll take offers, but the 630 goes with it

The 630 you bought from Nick?

David Young is smarter at this stuff then me but for what it's worth I have tried plugging the return line in the past and my saws wouldn't run for chit with it plugged.

 

[David Young]

Interesting, maybe I’ll cap it and try it.

I had a leak at the boot and used Moto seal with the clamp. Saw would start and run perfect. If I let it set for 3 minutes it would lose prime and need to be choked. Closing it off turned it into a regular hs.

 

[davidwyby]

The 630 you bought from Nick?

David Young is smarter at this stuff then me but for what it's worth I have tried plugging the return line in the past and my saws wouldn't run for chit with it plugged.

Yes.

 

[davidwyby]

got a few mins…

Tried plugging off the return, no change.

adjusted idle up and it helped but only way up.

I noticed that if I rev it and let it stall and then pull the fuel line off it’s dry. It’s like it barely getting enough fuel. Back into the carb methinks. Or something with the impulse…hmm…


@Benwa

 

[Woodslasher]

got a few mins…

Tried plugging off the return, no change.

adjusted idle up and it helped but only way up.

I noticed that if I rev it and let it stall and then pull the fuel line off it’s dry. It’s like it barely getting enough fuel. Back into the carb methinks. Or something with the impulse…hmm…


@Benwa

Fuel filter?

 

[huskihl]

got a few mins…

Tried plugging off the return, no change.

adjusted idle up and it helped but only way up.

I noticed that if I rev it and let it stall and then pull the fuel line off it’s dry. It’s like it barely getting enough fuel. Back into the carb methinks. Or something with the impulse…hmm…


@Benwa

With the fuel line off the carb, fuel should spray out of the line if you shake the saw. Sounds like the filter and/or line might need a look

 

[Woodslasher]

With the fuel line off the carb, fuel should spray out of the line if you shake the saw.

Heck, every machine I touch seems to piss an insane amount of fuel out of the line when I disconnect them, regardless of whether I've shaken the tool or not.

 

[davidwyby]

Sooo…I think I fixed it but I’m not sure what I did.

The line and filter looked good last time. @Duke Thieroff had replaced them recently.

I replaced the boot. I didn’t like how the old one mated to the carb. The new one also sits more proud of the white plastic thing. I also tweaked and sanded the corners on the inner metal ring for better fit.


Old carb bore lines across raised lip.

New in plastic before metal ring. I think the ring pushed the raised lip out.

New out of plastic


I also blew out the carb and the needle arm was a little high which I corrected. I thought I had last time.
I only ran it a min so as not to bug the neighbors too much but doesn’t stall now even with the idle turned down. I hope to get to cut a bit tomorrow and try it. Left arm is still gimp from overworking it on the burnt trees demo though…

 

[davidwyby]

Heck, every machine I touch seems to piss an insane amount of fuel out of the line when I disconnect them, regardless of whether I've shaken the tool or not.

I disconnected the line and walked outside and turned on the air compressor. When I came back it was full. I decay…

 

[huskihl]

Heck, every machine I touch seems to piss an insane amount of fuel out of the line when I disconnect them, regardless of whether I've shaken the tool or not.

Well that means the filter is good

 

[Woodslasher]

Well that means the filter is good

Or it means that gasoline has an innate desire to be in close proximity to me, I know a few (dozen) people who would agree with the latter.....