PM 650 .. exhaust temp, & O2

[Duke_Spinner]

looking to get this saw running again, 30 years later ..

anyone got figures for the above ..??

any reason to suspect crank seals on these ..?

this was my small saw, with a 16" bar on her ..

whadda cuttin' pig it was ...

 

[Duke_Spinner]

c'mon ..nobody tunes by exhaust temp, and oxygen ..?? :help:

 

[Goat]

What do you mean tune by "oxygen"?

 

[Duke_Spinner]

% o2 ....

prolly about 2.5 %, i'm guessing ...
i usedta race 2 strokes ..think Yammie RZ 350

 

[Goat]

Now you have me interested...I don't mean to derail your thread here, but I can't help my self. How do you do it? If you use an O2 sensor you'd need to use a wideband unit or are you talking gas analyzer?

I've pondered the idea of tuning a saw via a lambda sensor but I think that the muffler in a chainsaw is too small to prevent reversion. End result would be a very rich tune....

 

[ray benson]

Carb on PM650 is a Walbro HDB, initial adjustment of low and high speed mixture needles is one turn
open from a lightly seated position. Make final adjustments with engine warm and running. Be sure air
filter is clean before making final carb adjustment. Adjust idle speed screw so engine idles just below
clutch engagement speed. Adjust low mixture needle so engine will accelerate cleanly without hesitation.
Adjust high speed mixture needle to obtain optimum performance under cutting load. Saw should never
be operated with high speed mixture needle set less than one full turn out unless in high altitude area, as
engine could be damaged from lack of lube.

Recommended plug is AC CS45T, Champion RDJ6 or equivalent. Plug gap .025".

 

[Duke_Spinner]

Now you have me interested...I don't mean to derail your thread here, but I can't help my self. How do you do it? If you use an O2 sensor you'd need to use a wideband unit or are you talking gas analyzer?

I've pondered the idea of tuning a saw via a lambda sensor but I think that the muffler in a chainsaw is too small to prevent reversion. End result would be a very rich tune....

i have a combustion analyzer .....O2, C0, temp, % excess Air