088 starting issue

[zimmy]

hi have an 088 with poly flywheel which nearly takes fingers off when starting, decomp pops nearly every pull and has a mettalic clank on top dead centre, when i can get it to start it runs reasonably well any ideas on cause of problem would be a great help, fed up with bruised fingers now

 

[Gumnuts]

g'day

Hi,
Don't like the sound of the metalic clunk.Would be taking the pull start cover off and manually winding slowly to try and isolate the sound.
Pull the jug if it is not something simple like the sound of flywheel hitting the ignition coil / bruised fingers / check the coil is tightened down.Space flywheel to coil gap / use a good business card.
How long have you had the saw ? When did you first notice ?
Briused fingers / hold thumb back on decomp for each pull.

 

[zimmy]

only got saw this morning, guy gave it to me he was pissed with it, have had pull start off and done air gap you hear noise as you pull over, no noise when plug is out

 

[Saw Dr.]

Metallic noises in saws are ALWAYS bad. I suspect foreign object on top of piston, or crank bearing (cage) failure. If the bearing cage has failed, that would cause the sound and the ridiculous effort on the starter. You need to figure out what is up with it, or you'll end up replacing a bunch of EXPENSIVE parts.

 

[Gumnuts]

Metallic noises in saws are ALWAYS bad. I suspect foreign object on top of piston, or crank bearing (cage) failure. If the bearing cage has failed, that would cause the sound and the ridiculous effort on the starter. You need to figure out what is up with it, or you'll end up replacing a bunch of EXPENSIVE parts.

Agree

How does compression feel ?
Can you remove muffler have squiz at piston / cyl / rotate slowly /
with torch / spec top of piston too.Any scoring / scratches ?
Secondhand /expensive saw.Suggest take off the cylinder and check wear/marks.Check slop in piston/gudgeon pin bearing/ big end bearing.


Possible previous guy left the base gasket out.
Recommended plugs / (Prefer) NKG BPMR 7A ?
Or Bosch WSR 6F .

 

[Saw Dr.]

Agree

How does compression feel ?
Can you remove muffler have squiz at piston / cyl / rotate slowly /
with torch / spec top of piston too.Any scoring / scratches ?
Secondhand /expensive saw.Suggest take off the cylinder and check wear/marks.Check slop in piston/gudgeon pin bearing/ big end bearing.


Possible previous guy left the base gasket out.
Recommended plugs / (Prefer) NKG BPMR 7A ?
Or Bosch WSR 6F .

"torch" to a brit is a flashlight in american english. I DO NOT suggest trying to inspect the top of the piston with a propane torch.

 

[Gumnuts]

Lol

 

[rxe]

Regardless of noise, if I picked up a big saw like that...I would have the piston and cylinder out as a matter of course. You might catch something that deflects a really expensive bill. For the price of a base gasket, you could avoid a £300 bill for parts....

 

[timberwolf]

I would be pulling the head off to make sure all is well inside. After that pull and clean the decomp, to make life easy drill the hole in the side of the decomp out to 3/64 even 1/16.

Checking that it is not the fly wheel hitting the coil or something clutch side makeing the noise is good advice as well.

 

[Stihl088stock]

Make sure the flywheel is tight. Pull the cyl and clean any carbon crispies out...

...Then buy a $2k macro camera setup and post photos! LoL!

 

[Dan_IN_MN]

only got saw this morning, guy gave it to me he was pissed with it, have had pull start off and done air gap you hear noise as you pull over, no noise when plug is out

Is it the correct plug? When you hear the noise do you feel it too? Do you feel an impact of some sort?

Like others have said....pull the cylinder and check thing out in there.

OP... You said that the saw "nearly takes fingers off when starting". Do you hear the saw fire when the starter handle is riped out of your hand?

 

[zimmy]

thanks for replies it has ton of compression was on mill so has pretty dodgy cable to operate throttle which creates issues with idling etc, but leaning towards timing issue as it pops decomp every pull, saw is firing but rips fingers on every pull,scared of it now think noise maybe needle cage so will pop cylinder today maybe loose cage is causing timing issue?

 

[blsnelling]

A loose rod bearing isn't going to affect your ignition timing. Reguardless, you're doing the right thing to pull it down. Parts are way too expensive on these to take chances. I'd pull the flywheel and check the key as well.