problem MS200t

[Eddy_t]

would a scored piston pass the crankcase pressure and vacuum test i did but still cause problems ?

 

what i saw of the piston via the ports did not look great.

 

You need to do a compression test then, scored pot n piston means its FUBAR tbf, need new ones

 

 

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[GardenKit]

Thats fine - I have noticed the old school big carbs pop off but the smaller modern ones don't at these pressures - what you have is OK!

They do need to pop off at some point though and its not a good idea to pump them too high.

 

Better to test them by pumping up to around 20 psi with the carb assembled, then apply vacuum to the cylinder end of the carb and watching the needle drop when the diaphragm pulls down.

 

I usually just cover the inlet end of the carb throat with my thumb and suck on the cylinder end.

 

If you are cautious of putting a carb to your lips you can test it on the saw by pulling the engine over, each stroke should see the pressure drop as the induction vacuum pulls the diaphragm down.

[Rich2484]

would a scored piston pass the crankcase pressure and vacuum test i did but still cause problems ?

 

what i saw of the piston via the ports did not look great.

 

Yes it would still pass. As you are pressure testing a "sealed" case. With plug in, exhaust blocked and inlet blocked its a sealed unit.

 

The oppression needs testing to see it the cylinder or piston is shot. Low comp means something's gone. And on a strip down it will then become apparent what is up.

[SpannerRat]

doing that gets me just under 180 psi

 

I think that's been done?

 

 

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[waterworks]

looks like i will have to get rid of it, it's beaten me.

[Rich2484]

Ok. Send it one of us on here. I'm sure we can take a good look.

[spudulike]

looks like i will have to get rid of it, it's beaten me.

 

It happens - the MS200 can be a fiddly machine to work on and have a few known issues but are good machines and pesonally find them pretty easy to work on and fix - it is the first few that are difficult - after that....no problems:thumbup:

[Rich2484]

It happens - the MS200 can be a fiddly machine to work on and have a few known issues but are good machines and pesonally find them pretty easy to work on and fix - it is the first few that are difficult - after that....no problems:thumbup:

 

Second that. I'm on a total of 6 now. 7 if you include the one I stripped and made a good one from two.

 

The first one was the hardest as trying to figure out as the symptoms of the carb issue and bad crank seals are the same so you end up in circles....

 

I love working on the 200t saws and love them.