Restored Stihl Contra 1106 hard starting when cold

[A2build]

Hey guys my first post here, I’ve done a complete restoration on my Stihl Contra and have replaced tons of parts, the issue I’m having is it is hard starting when cold 30 plus pulls, when it gets going and you shut it off it fires back up on the first pull, I am a little stumped on whether it is a low compression? Timing? Fuel issues?(Fuel gets up the the carb way before it starts) any help would be appreciated I’ll link some pics. Thanks in advance

 

[pioneerguy600]

Choke closes tightly? Throttle slightly open.?

 

[Gord404]

compression seems a bit low- did you re-ring it?

 

[A2build]

Thanks for the reply guys, i was actually a bit confused on the choke mechanism on that saw it is the air vane type so I didn’t see any way to engage it for a cold start, and throttle lock was on when starting it. I was also thinking the compression seemed a tad low when I tested it, I did put in new oem rings in it and they had maybe 5min of run time when I did the test, thanks again.

 

[A2build]

one more thing I forgot to add, on the compression is it better to do it cold or warm? That test was done cold with throttle wide open

 

[pioneerguy600]

one more thing I forgot to add, on the compression is it better to do it cold or warm? That test was done cold with throttle wide open

Cold and throttle position does not matter as air will rush in through the exhaust port to replenish any air sent up the compression tester hose. The compression tester appears lie the type that does not have a Schrader valve in the very tip where the hose enters the sparkplug hole. Any compression tester for small engines needs that Schrader valve in its very end, if not located there readings will always be lower.

 

[A2build]

Cold and throttle position does not matter as air will rush in through the exhaust port to replenish any air sent up the compression tester hose. The compression tester appears lie the type that does not have a Schrader valve in the very tip where the hose enters the sparkplug hole. Any compression tester for small engines needs that Schrader valve in its very end, if not located there readings will always be lower.

 

[A2build]

Yes my compression tester does have a schrader valve on the very tip where it threads into the spark plug hole, I’ve tested tons of saws both small and big and I think the tester is pretty accurate so I don’t think that’s the issue.

 

[stihltech]

That is a minimum compression by most standards. I ask if you degalzed the cylinder, but I get shot for asking.
I would definitely get some more run time on it before getting too worried. Get it started, set a good idle, and walk away. I like ti let them run 10 to 15 minutes.
Try that first. Rings got to seat, one way or another.

 

[A2build]

That is a minimum compression by most standards. I ask if you degalzed the cylinder, but I get shot for asking.
I would definitely get some more run time on it before getting too worried. Get it started, set a good idle, and walk away. I like ti let them run 10 to 15 minutes.
Try that first. Rings got to seat, one way or another.

Thanks for the response, I did scuff up the cylinder with some scotch brite but no honing should I have honed the cylinder? do you know if that is a crome or Nikasil platted cylinder? I’ll get it going and and run it for a while when I get some time it should pop right off with some fuel down the carb.

 

[stihltech]

If you scuffed it up so you could see some very fine marks, you should be OK. After rereading your post,
I am more concerned with basics. Spark when cold? Did you time the points? Will it fire with a little prime through the carburetor?
I would verify those issues first. Compression is a maybe, but that should be a hot and could issue.
My magic wand says we need to get the fuel to the cylinder when cold. And of course, a good choke.

 

[Jay Hansen]

Beautiful saw!
The air vane that is linked to your choke lever is the governor, which closes the choke if the rpms get too high, thereby richening the air/fuel ratio and slowing the engine down. To choke when starting, swing the choke lever all the way down until you feel the detent lock in. Now the choke will be closed properly, and I think It'll start ok.
If it runs and starts ok once you've had it running, compression probably isn't causing your cold start issue.