TerraForte
Member
- Joined
- Jun 17, 2019
- Threads
- 7
- Messages
- 33
Got another stumper
Got carried away and got a Poulan chainsaw in a package deal. A "Woodsmaster 2250, 2.2CID"
Older model, seems slightly more solid than newer Poulan stuff
36cc motor, Walbro carb originally.
Got it as a jumble of parts, but everything present. Put it back together and it surprisingly fired right up.
At that point, it would rev, but would not idle. I could start it at full throttle and seemed to run indefinitely but would die upon coming down.
One of the vibration-damper springs was also broken.
Not something anyone wants to buy in this condition, but also not worth scrapping since the saw looked cosmetically nearly brand new.
So I figured I'd buy a spring kit and a clone-carb for $20 total.
Springs were quite nice actually.
Saw idled perfectly! But then died under load.
I must have spent an hour trying to tune that stupid thing but I couldn't get it right. I would turn them both all the way in, then CCW the Low ~1/2 turn until it idled perfectly, then CCW the H extremely slowly. I couldn't seem to get results that made any sense when enriching the H. I'm prepared for the "junk clone carb is junk" reply.
It will either idle perfectly and die under load, or only start under full throttle, run perfectly, then die when coming to idle.
I would get the low speed circuit tuned in perfectly, then go for the high. I would adjust the high a bit, and then it wouldn't idle! And wouldn't re-start until re-tuning the low. Then it wouldn't rev!
It was this never ending loop of either low or high speed working, but never both.
What gives?
When does the low speed circuit taper off? How much overlap between H/L circuits on these small carbs? I'm familiar with the multiple curves on a CV carb on a motorcycle, for example, always 2 or 3 jets in contribution, but I'm sure these small carbs aren't as 'smooth'.
Got carried away and got a Poulan chainsaw in a package deal. A "Woodsmaster 2250, 2.2CID"
Older model, seems slightly more solid than newer Poulan stuff
36cc motor, Walbro carb originally.
Got it as a jumble of parts, but everything present. Put it back together and it surprisingly fired right up.
At that point, it would rev, but would not idle. I could start it at full throttle and seemed to run indefinitely but would die upon coming down.
One of the vibration-damper springs was also broken.
Not something anyone wants to buy in this condition, but also not worth scrapping since the saw looked cosmetically nearly brand new.
So I figured I'd buy a spring kit and a clone-carb for $20 total.
Springs were quite nice actually.
Saw idled perfectly! But then died under load.
I must have spent an hour trying to tune that stupid thing but I couldn't get it right. I would turn them both all the way in, then CCW the Low ~1/2 turn until it idled perfectly, then CCW the H extremely slowly. I couldn't seem to get results that made any sense when enriching the H. I'm prepared for the "junk clone carb is junk" reply.
It will either idle perfectly and die under load, or only start under full throttle, run perfectly, then die when coming to idle.
I would get the low speed circuit tuned in perfectly, then go for the high. I would adjust the high a bit, and then it wouldn't idle! And wouldn't re-start until re-tuning the low. Then it wouldn't rev!
It was this never ending loop of either low or high speed working, but never both.
What gives?
When does the low speed circuit taper off? How much overlap between H/L circuits on these small carbs? I'm familiar with the multiple curves on a CV carb on a motorcycle, for example, always 2 or 3 jets in contribution, but I'm sure these small carbs aren't as 'smooth'.