McCulloch 10 10 diagnostic help needed

[Mastermind]

I've seen much worse run well. Just sayin.

 

[Willoughby]

Just for fun did you put some oil in the cylinder for a wet test?

that's with oil its about 80 without oil

 

[Willoughby]

yall think this compression is ok to start and run ? its got good spark , and adding fuel dont help . Im outa ideas except a jug and piston , Im open to any and all suggestions

 

[huskihl]

How many pulls did it take to get to 85?

 

[Mastermind]

How many pulls did it take to get to 85?

Excellent question.

 

[Steve]

yall think this compression is ok to start and run ? its got good spark , and adding fuel dont help . Im outa ideas except a jug and piston , Im open to any and all suggestions

Any of the 10 series with a DSP valve (compression release) have 30-35psi compression. They start just fine. Not saying 80psi is great but it should do something. Pop, spudder, make noise.

Is the sparkplug wet or dry after an attemp to start?

My point is if the auto oil pump is leaking into the crankcase the crankcase wont build pressure to move fuel into the transfers and into the combustion chamber. Would leave you with a dry plug.

If the plug was wet then you are getting fuel into the cylinder and you would have a spark/compression issue. But at 80 psi it should do something.

 

[Willoughby]

How many pulls did it take to get to 85?

5 pulls

 

[Willoughby]

Any of the 10 series with a DSP valve (compression release) have 30-35psi compression. They start just fine. Not saying 80psi is great but it should do something. Pop, spudder, make noise.

Is the sparkplug wet or dry after an attemp to start?

My point is if the auto oil pump is leaking into the crankcase the crankcase wont build pressure to move fuel into the transfers and into the combustion chamber. Would leave you with a dry plug.

If the plug was wet then you are getting fuel into the cylinder and you would have a spark/compression issue. But at 80 psi it should do something.

its wet , and I've tried adding fuel ,manual oiler does it also have auto ?

 

[Mastermind]

its wet , and I've tried adding fuel ,manual oiler does it also have auto ?

Steve knows these saws....he's the man to help. I'm sure we can find parts if needed too. You're in the right place to learn about vintage saws.

 

[Steve]

Steve knows these saws....he's the man to help. I'm sure we can find parts if needed too. You're in the right place to learn about vintage saws.

Thanks Randy.

And i have the parts. Just need to make sure what we need.

 

[huskihl]

5 pulls

Try 10 pulls and see where it's at

 

[Mastermind]

Thanks Randy.

And i have the parts. Just need to make sure what we need.

I've been inside some of the 81s looking for gains. There really wasn't anything much I could find. Well engineered machines.

 

[Steve]

its wet , and I've tried adding fuel ,manual oiler does it also have auto ?

Yes. If you take the single flat screw off the oil tank cover and remove it inside you will see a black plastic thing attached to the top of the tank. That is the auto oil pump.

 

[Mastermind]

I'd clean up that carbon smear, add a set of rings, some seals.....and make that little jewel sing.

 

[Willoughby]

I'd clean up that carbon smear, add a set of rings, some seals.....and make that little jewel sing.

sweeeeeeet

 

[Willoughby]

My point is if the auto oil pump is leaking into the crankcase the crankcase wont build pressure to move fuel into the transfers and into the combustion chamber. Would leave you with a dry plug. if we've ruled out compression as a issue and it has good spark it has to be something like this Ill take it apart and see how it works then
Ill put it back together and dry everything off good then see if the plug gets wet . Steve seems to know his McCulloch"s
and guys I got saws to use , a plenty , but I want to KNOW what makes this thing tick, ... or not tick.. thanks to all the great advise guys Really I mean it THANKS

 

[Willoughby]

latest update ; inspected auto oiler & sealing surface , no visible issue, reassembled everything dried plug with brake clean and air , 1 pull it coughed! 5 pulls on choke plug is damp , but not wet m after a few more attempts to make it cough again there is fuel dripping out of exhaust , plug defiantly has fuel on it but not dripping , no more pops or cough just the one initially . I'm hoping someone has an idea , something to try next , I measured compression on a 2 more 610 mcculochs and 2 husqvarnas that run well & they were 120-150 psi its been mentioned that they should run as low as 35 psi so whats going on here is beyond me any thoughts appreciated

 

[Mastermind]

latest update ; inspected auto oiler & sealing surface , no visible issue, reassembled everything dried plug with brake clean and air , 1 pull it coughed! 5 pulls on choke plug is damp , but not wet m after a few more attempts to make it cough again there is fuel dripping out of exhaust , plug defiantly has fuel on it but not dripping , no more pops or cough just the one initially . I'm hoping someone has an idea , something to try next , I measured compression on a 2 more 610 mcculochs and 2 husqvarnas that run well & they were 120-150 psi its been mentioned that they should run as low as 35 psi so whats going on here is beyond me any thoughts appreciated

You're flooding the hell out of it.

 

[Steve]

After it poped did you push the choke all the way in and give it full throttle?

 

[Willoughby]

After it poped did you push the choke all the way in and give it full throttle?

yes sir, never popped again