JS 621 carb and fuel ?

[roncoinc]

JUst got the saw,free,owner had to many problems with it..the carberator falling off it was so loose didnt help ..the mufller falling off didnt help either..
H/L scews all the way in tight also..
noticed the muffler was completely hollowed out and some xtra holes drilled in the front,total area would be about the size a 1/2 in drill would make..noticed looking in the top edge of the piston was cut down on the exhaust side..didnt look like port had been touched.
put some mix in and fired up second pull..then shut it down.had set H/L screws one turn out..
so first question is about the fuel mix..do i remember corectally those used a 32 mix ?? using the new quality oil would make a differance in the ratio ?
i dont want to run it without enough oil in the mix and want the mix rite so i can tune it properly..
also with this muffler "mod" should i run the hi side a little rich ? or will having an empty muffler prevent tuning properly anyway ?
thank you.

 

[PB]

I would take a closer look at the piston and cylinder before you try to run it anymore. There might be serious damage that you can't see, and could get worse when you run it.

50:1 will work fine with the newer oils, just make sure you have fresh gas.

 

[Maldeney]

Are you sure it's not under warranty?

 

[roncoinc]

When i had the carb off,the muffler ofd anf the sparkplug out i gave it as good an inspection as i could and i looks like everything is perfectally fine..
was pleased to see double rings and compresion of 180 lbs..
thanks for the oil info..
on the warranty,i dont think it came with the extended warranty plan

 

[SawTroll]

...

50:1 will work fine with the newer oils, just make sure you have fresh gas.

:agree2:

The specs call for 25:1, but mine has been run on Aspen alky fuel with 50:1 (high quality synth oil) at least since 1992!

 

[roncoinc]

Thanks Troll,,i used the all in one one/one for all good for everything in a hi quality oil and added a little xtra to be on the safe side..
DAMN that thing SCREEMS with that open muffler and cut piston,i think i may have to close off some of the xtra holes as idle seems hard to control..also looks like somebody eliminated the base gasket too.
only problem now is no oil to bar..i will start a new post on that and hope you will share your expertise on that also..
thank you..