Jonsered 2165 WILL NOT start

[chunez]

So I picked up a cherry Jonsered 2165 off marketplace and the guy said he had started it up 2 months before I bought it. When I get it, it will not even think about starting. Best I could get is 3 gurgles after dumping fuel into the intake and holding the trigger down while pulling. Compression is 130, no visible scoring on the piston from the intake or exhaust side. I haven’t pulled the jug. I bought new OE parts for the usual suspects and for the more expensive parts I swapped from another running 2165 I have on hand. Here is what I have done so far:
New plug (ngk)
New fuel pickup and impulse line (oe)
New fuel filter (oe)
New carb kit (oe)
Disconnected stop switch
Verified spark outside of cyl
Swapped coil
Swapped flywheel, checked key
Swapped gas tank
Swapped carb
Swapped recoil assembly

All this with NO IMPROVEMENT. Starting to pull my hair out on this one. I just got new base gaskets in so I can pull the jug next but given compression seems acceptable and no scoring I am hesitant to do so. If it was an air leak, you would think it would at least run for a little bit. Only other thing I can think of is the intake boot, but visual inspection didn’t reveal anything. Running 40:1 red armor on 93 non ethanol.

I’m a parts-swapper, I never said I was a mechanic!

 

[Bob Hedgecutter]

Sounds like it might be time to pressure and vacuum test- if you can verify at least one of the carb swaps is picking up fuel and getting it to the combustion chamber and your compression reading is true to scale- then thats about all that is left.

 

[cuttinstihl]

Check for any air leaks, pressure and vac test is easiest way to find out

 

[huskihl]

It’s likely flooded

 

[chunez]

So an air leak could completely prevent the saw from starting? I thought they caused them to not tune and run funky but not completely prevent start

 

[chunez]

It’s likely flooded

Oh I’ve learned my lesson on other saws. After reefing on it a bunch I take the plug out, pull it over a few times, spray it out with canned air and let it sit overnight

I have pulled and pulled without touching the trigger and without pouring any gas into the intake and there is no signs of life. As soon as I put some gas in the intake it pops on the next 2-3 pulls but won’t run. If I keep pulling it stops popping until I add more fuel to the intake

 

[huskihl]

So an air leak could completely prevent the saw from starting? I thought they caused them to not tune and run funky but not completely prevent start

You are pretty much correct

 

[Bob Hedgecutter]

So an air leak could completely prevent the saw from starting? I thought they caused them to not tune and run funky but not completely prevent start

well the previous owner probably lived through the hard to tune stage- then sold it.
You bought it and inherited the bad mojo.
They can be that bad- yes and if your not flooding it constantly pulling the rope as Kevin suggest above- a major leak is a possibility.

 

[chunez]

well the previous owner probably lived through the hard to tune stage- then sold it.
You bought it and inherited the bad mojo.
They can be that bad- yes and if your not flooding it constantly pulling the rope as Kevin suggest above- a major leak is a possibility.

The previous owner was an older gentleman who was a jonsered collector. I bought 5 saws from him and he has been very nice to work with. He’s offered me a full refund or partial refund or free parts but I really wanted to get to the bottom of it before we settled up. I don’t think he was trying to pull anything over on me.

Guess it’s off to buy a leakdown test kit. Any recommendations?

 

[Bob Hedgecutter]

If you are planning to work on a lot of saws- Mityvac 8500 kit.

 

[chunez]

What about the intake/exhaust blocks?

 

[Bob Hedgecutter]

Bit of sheet rubber- like cut outs of old inner tubes and blanking plates over- or the carb and muffler back on as the blanking plates.

 

[steele_109]

Hi i did a rebuild on a 372 a few years back and forgot to put the new seals in.But i could get it to run it wouldn't idle but it would run.My guess is a stopped up muffler screen.That's the only thing i know of that will stop them cranking,when they have every thing else they need.

 

[kd.rodgers]

The lack of improvement makes me lean toward an inside issue with the cylinder or piston. Can be bad rings, a cracked or scored piston.

 

[steele_109]

It could be,I had a man bring a stihl ms 250 that wouldn't crank.Come to find out it had a hole in the top of the piston, everything else was ok.

 

[dave ensign]

"Real" bad air leak or plugged muffler screen.

 

[Bart01]

Had a similar problem with my jonsered 49sp.
Turned out that the cilinder head was loose and bottom cyl gasket was shot. So mayor air leak, but my compression test was good.
Did a pressure test, and crankcase was not holding pressure !
Is fuel getting into the carb ? I used a transparent fuel hose, so i could see that no fuel was coming up into the carb.... Mayor air leak will prevent fuel getting into the carb !
Block exhaust and intake with a piece of rubber and do a pressure test. Or inspect your cilinder head and bottom gasket or crackcase seals could also be the problem...

 

[chunez]

Had a similar problem with my jonsered 49sp.
Turned out that the cilinder head was loose and bottom cyl gasket was shot. So mayor air leak, but my compression test was good.
Did a pressure test, and crankcase was not holding pressure !
Is fuel getting into the carb ? I used a transparent fuel hose, so i could see that no fuel was coming up into the carb.... Mayor air leak will prevent fuel getting into the carb !
Block exhaust and intake with a piece of rubber and do a pressure test. Or inspect your cilinder head and bottom gasket or crackcase seals could also be the problem...

Good timing, I just plopped the 2165 back on my bench last night to get it sorted out! Picking up a mityvac today, I’m guessing major air leak as well