Chainsaw hard to start.

[tomalophicon]

Bike pump was a failure because it bleeds air. Will get a proper pressure pump and report back

 

[J D]

Bike pump was a failure because it bleeds air. Will get a proper pressure pump and report back

Get pressure up to +10PSI, crimp hose to seal it, wait a minute or so, un-crimp hose & listen for the pssst of pressure escaping... If it's still got pressure enough to hear carb should be good.
Not ideal, but working with what ya got...

 

[tomalophicon]

Get pressure up to +10PSI, crimp hose to seal it, wait a minute or so, un-crimp hose & listen for the pssst of pressure escaping... If it's still got pressure enough to hear carb should be good.
Not ideal, but working with what ya got...

Good idea. Thanks. Will give it a go.

Was thinking also I could pump it up and spray some soap suds over the whole shebang to see if I can detect any leaks.

 

[Husky Man]

Read the owners manual? Who does that?????????

Reading the owners manual was my MISTAKE with my 3120XP, and what lead me to AS

With MY 3120XP, and others here have reported the same situation, you do NOT use Choke AND Throttle Lock

I have found that using Choke ONLY, about 3 pulls and she will Snort, then Choke OFF, and another 2-3 pulls, and she will wake half the county

The manual says to use Choke and Throttle Lock, which is what my 266XP “Ol’ Reliable” Likes, so naturally that is what I did. Well 40-50 pulls on a 3120XP, even using the Decomp valve, will flat wear a guy out.

Enter AS, and @ Bigblock, and the solution

There’s an exception to every rule, the 3120XP is one to the Choke and Throttle Lock Cold Rule, but then again, I’m the exception to a LOT of Rules

Doug

 

[tomalophicon]

Reading the owners manual was my MISTAKE with my 3120XP, and what lead me to AS

With MY 3120XP, and others here have reported the same situation, you do NOT use Choke AND Throttle Lock

I have found that using Choke ONLY, about 3 pulls and she will Snort, then Choke OFF, and another 2-3 pulls, and she will wake half the county

The manual says to use Choke and Throttle Lock, which is what my 266XP “Ol’ Reliable” Likes, so naturally that is what I did. Well 40-50 pulls on a 3120XP, even using the Decomp valve, will flat wear a guy out.

Enter AS, and @ Bigblock, and the solution

There’s an exception to every rule, the 3120XP is one to the Choke and Throttle Lock Cold Rule, but then again, I’m the exception to a LOT of Rules

Doug

Thanks - so once it snorts do you release choke and engage throttle lock or nothing?

 

[Husky Man]

Thanks - so once it snorts do you release choke and engage throttle lock or nothing?

Just release the choke, the 3120XP is a beast, a whole different critter than what you’re working on. My 266XP is a close cousin of your 272XP, and it has earned it’s nickname “Ol’ Reliable”, it can sit for months and rarely takes 3 pulls to start, it is the saw that made a Husky Believer out of me, and one saw that I will Never Sell

Doug

 

[tomalophicon]

So the carb is leaking around the cover here. I will double check the order of the gaskets etc a bit later. Is it likely that the cause for the starting trouble is linked to these air leaks?

 

[tomalophicon]

The one thing i'm not sure about now is the order of the 2 pumps as circled.
81180 is pump diaphragm
81150 is diaphragm pump.

One is black rubber and the other is a white/translucent material. Any idea which one is which?

The gasket is is also twice as thick as the original.

Cheers

Tom.

 

[J D]

Did it originally have 2 diaphragms? I suspect there are 2 to cover carb variations & you should fit the one appropriate for your carb. Gasket thickness shouldn't matter on that side

 

[tomalophicon]

Did it originally have 2 diaphragms? I suspect there are 2 to cover carb variations & you should fit the one appropriate for your carb. Gasket thickness shouldn't matter on that side

Hi JD
Yes it did and that is the IPL for the specific saw.
Tom.

 

[tomalophicon]

I flipped the 2 diaphragms around and she shot flames out the exhaust more than before!

I then de-flooded it and turned the L screw in about half a turn and it fired up nicely with no more explosions and flames. The L screw is around 1 turn out from seated so we'll see how it goes this afternoon when I try again.
Hopefully it was just way too rich on the low side causing flooding.

I also managed to stop the carb from bubbling out the cover like that.

Pressure tested fuel line and impulse line and both passed.

Thanks for all the help so far.

 

[tomalophicon]

I now know my pump diaphragms are in the correct place. Still no bueno unless I pull 20 times until it sputters into life.

I'll pull the flywheel tonight and inspect the key. If the key is OK I have an unknown spare coil and an exciter that I can use.

Question for the experts: The other coil has damaged plug wire insulation but the wire itself looks fine. Can I use standard heat shrink on that or do I need something more heavy duty?
thanks.

 

[tomalophicon]

Rebuilt the spare carb I had and still backfired out the carb and the lighter muffler.

Pulled the flywheel. The key was in place and secure.

Replaced the coil with a spare used unit and repaired the damaged insulation with 2 layers of heatshrink.

IT WORKS AGAIN! STARTED FIRST GO.

thanks everyone for your assistance. I found a new coil for sale locally which i'll grab as a backup for future use.

Cheers

Tom

 

[rupedoggy]

Now whatever you do don't clean it. They run so much better dirty.