JT6120

Husqvarna 181se on the bench

converted to 88 cc using a k&s non decomp cylinder off a early 288xp

new seals new bearings 6202 on flywheel side and 6203 on clutch side. 
Primary coil from a Jonsered 910, new fuel line, new decals, HD intake and air filter

plus a full wrap 

29 minutes ago, spudulike said:

Just read this again....check the low speed setting on the carb, if the saw loads up a bit under full throttle, when the throttle is snapped shut, it can give the saw more fuel than it can deal with so the idle plummets then picks up.

Make sure the H speed is set to around 13Krpm and the low speed isn't set too rich......and make sure the air filter is fully cleaned!

Great info there particularly on the coil gap 

its gapped correctly as described to 0.3mm

There is an aftermarket coil in it so I might switch it with an oem one just to check 

20 hours ago, spudulike said:

I got that puller from Husqvarna 

I think it’s a 346xp one

shes back together and running although the carb seems a bit temperamental going between a high idle and very low idle when returning from full throttle 

is this a common issue with these carbs?

Gasket in and reassembled with new case seal and crank seal on flywheel side

The case gasket appears to have failed as the bar oil is leaking under the exhaust 

This led me to the hypothesis that this may also be the cause of the piston issue

with potential ingress of bar oil into the crank case

had to split the case to replace gasket and was surprised to find three case bolts were not tight 

once split I am convinced bar oil is getting in to crankcase

First time post but decided I would add to the whats on the bench post as I think it seems like a very open way of sharing what you’re up to chainsaw wise

So here goes

A friend of mines 365xt on the bench with a scored looking piston 

cylinder off and this is the observation 

piston looks bad cylinder looks perfect 

very strange