dayton/245 poulan carb problem

[leo58]

Haven't been working on saws due to medical issues for about 3 years. Doing the dialysis thing now. Picked up a dayton/poulan 245 and an echo 302. Both pristine. Done a carb rebuild on both. I have rebuilt lots of 2 cycle carbs with good success before hospital/doctors etc. I went thru both carbs and they both have the same issues. Starts and runs well but after 2/3 minutes dies and won't start without a prime then runs well for 2/3 minutes and dies again. I have tuned both repeatedly with no change. What did I miss. I want to use the dayton for firewood cutting as what time I could get it to run it is a hoss. Currently using a Pro-mac 10-10. Dayton is 20cc bigger and approximately 3 lb lighter. Any advice would appreciated. I have a new PC and haven't got the picture thing figured out yet. I am from the 8- track and pin ball era so slow to grasp it.

 

[leo58]

I apologize for not owning a late model STIHL saw. I also appreciate all the helpful advice on my insignificant saw dilemma. I was trying to avoid trial and error to solve my problem. Again i thank everyone.

 

[Old2stroke]

Haven't been working on saws due to medical issues for about 3 years. Doing the dialysis thing now. Picked up a dayton/poulan 245 and an echo 302. Both pristine. Done a carb rebuild on both. I have rebuilt lots of 2 cycle carbs with good success before hospital/doctors etc. I went thru both carbs and they both have the same issues. Starts and runs well but after 2/3 minutes dies and won't start without a prime then runs well for 2/3 minutes and dies again. I have tuned both repeatedly with no change. What did I miss. I want to use the dayton for firewood cutting as what time I could get it to run it is a hoss. Currently using a Pro-mac 10-10. Dayton is 20cc bigger and approximately 3 lb lighter. Any advice would appreciated. I have a new PC and haven't got the picture thing figured out yet. I am from the 8- track and pin ball era so slow to grasp it.

Sounds like the fuel pump section of the carb is not working. If you are saying that 2 different carbs used on the same saw have the same problem, the only obvious thing in common would be the impulse pressures coming from the crankcase to operate the fuel pump. Does that saw have an external impulse line or does it get it though the carb mount base?

 

[pioneerguy600]

The impulse comes through the carb adapter block, one needs to be careful that the correct gasket is used between the carb and block that the impulse port hole lines up correctly, I have seen cases of wrong gaskets being installed that blocked the impulse passage.

 

[grizz55chev]

Haven't been working on saws due to medical issues for about 3 years. Doing the dialysis thing now. Picked up a dayton/poulan 245 and an echo 302. Both pristine. Done a carb rebuild on both. I have rebuilt lots of 2 cycle carbs with good success before hospital/doctors etc. I went thru both carbs and they both have the same issues. Starts and runs well but after 2/3 minutes dies and won't start without a prime then runs well for 2/3 minutes and dies again. I have tuned both repeatedly with no change. What did I miss. I want to use the dayton for firewood cutting as what time I could get it to run it is a hoss. Currently using a Pro-mac 10-10. Dayton is 20cc bigger and approximately 3 lb lighter. Any advice would appreciated. I have a new PC and haven't got the picture thing figured out yet. I am from the 8- track and pin ball era so slow to grasp it.

Might not be a carb problem, check the fuel line for cracks and inspect the intake filter for proper flow. Also check for blockage on the intake side of the carb at the elbow where the fuel line connects. Some carbs have a hidden fuel screen in the elbow. Keep us posted on your progress!

 

[thenne1713]

Sounds like the fuel pump section of the carb is not working. If you are saying that 2 different carbs used on the same saw have the same problem, the only obvious thing in common would be the impulse pressures coming from the crankcase to operate the fuel pump. Does that saw have an external impulse line or does it get it though the carb mount base?

short Fuel line (carb to Primer) MUST be straight, not crimped, must be able to FREE FLOW; trim until straight?

 

[Old2stroke]

short Fuel line (carb to Primer) MUST be straight, not crimped, must be able to FREE FLOW; trim until straight?

Primmer is only there to help getting the engine started. Should have no affect on how the saw runs if it is hooked up the right way.

 

[thenne1713]

FREE FLOW of fuel during RUN is required, and if this line is SLIGHTLY CRIMPED from being too long, it allows PRIME and START, but then runs out of fuel. SHORT version = Been there and DUN DAT. BELIEVE IT, FIX IT, (IF YOU HAVE THAT SYMPTOM/ ISSUE.)

 

[Old2stroke]

FREE FLOW of fuel during RUN is required, and if this line is SLIGHTLY CRIMPED from being too long, it allows PRIME and START, but then runs out of fuel. SHORT version = Been there and DUN DAT. BELIEVE IT, FIX IT, (IF YOU HAVE THAT SYMPTOM/ ISSUE.)

Are you sure you are talking about the line between the carb and the primer and not the fuel supply line from the filter to the carb?

 

[thenne1713]

Are you sure you are talking about the line between the carb and the primer and not the fuel supply line from the filter to the carb?

Yes, 100%, without giving the long worthless tale of things that did NOT work; if you do not believe, then I can only suggest cranking saw, and pinching that line shut and see what happens. Saw had new fuel line, cut to exact length of old, new fuel filter, died after 15-seconds, (even replaced carb which did not cure), but trimming that 1-inch+ line by 1/8" to straighten/ remove a very SLIGHT KINK Cured. I was AMAZED.

 

[redunshee]

Primmer is only there to help getting the engine started. Should have no affect on how the saw runs if it is hooked up the right way.

Primer? Neither saw use a purge bulb.

 

[Old2stroke]

Primer? Neither saw use a purge bulb.

Not talking about the OP's saw anymore, thread got sidetracked by silly stuff and I give up.

 

[pioneerguy600]

Not talking about the OP's saw anymore, thread got sidetracked by silly stuff and I give up.

I hear you, not everyone knows the workings of the older saws like those that owned, repaired and used them through the years. Many just offer up suggestions and don`t know the actual workings of the model that was originally asked about. When I first joined this site I too found it exasperating wading through the non accurate suggestions but slowly learned to let them go as on open forum threads and discussions will attract all sorts of replies.