372xp oe floods immediately after starting

[reed1517]

I am very new to rebuilding broken saws. Have successfully ported a 395 and a 372. Conservative porting, nothing crazy. Making transfers flow better, base gasket deletes, etc. the most recent 372 is a 2003 model with a 52mm hyway. I opened up the bottom transfers a bit more than I’m used to just to see how it would perform. The saw started great but immediately dies when throttle is left off. I can get all the excess fuel out and start the process all over again. I’ve rebuilt carb, replaced carb, checked flywheel key, swapped coil, replaced fuel line and filter, impulse hose. Passed pressure and vac test. Also played with the hi/lo/idle with no success. Compression is around 175. I’m concerned removing too much bottom transfer requires a little removal of upper to flow properly? I’m really stumped on this one. Any suggestions or info would be greatly appreciated

 

[reed1517]

I am very new to rebuilding broken saws. Have successfully ported a 395 and a 372. Conservative porting, nothing crazy. Making transfers flow better, base gasket deletes, etc. the most recent 372 is a 2003 model with a 52mm hyway. I opened up the bottom transfers a bit more than I’m used to just to see how it would perform. The saw started great but immediately dies when throttle is left off. I can get all the excess fuel out and start the process all over again. I’ve rebuilt carb, replaced carb, checked flywheel key, swapped coil, replaced fuel line and filter, impulse hose. Passed pressure and vac test. Also played with the hi/lo/idle with no success. Compression is around 175. I’m concerned removing too much bottom transfer requires a little removal of upper to flow properly? I’m really stumped on this one. Any suggestions or info would be greatly appreciated

Update: I widened the upper transfers about 1.5 mm and got the saw running. The carb needs turned down so low to run properly. The high jet is off and it’s still 4 strokin. Gonna lower the metering lever a bit to lessen the fuel. Anyone run into this situation?

 

[reed1517]

View attachment IMG_1045.MOV

Update: I widened the upper transfers about 1.5 mm and got the saw running. The carb needs turned down so low to run properly. The high jet is off and it’s still 4 strokin. Gonna lower the metering lever a bit to lessen the fuel. Anyone run into this situation?

Latest update: toasted the cylinder. The saw went from running rich to running extremely lean in a cut. Not sure how it happened or what went wrong. Lowered the metering arm the smallest amount under flush. The saw was running better but very sensitive to the slightest adjustment on the carb. Hopefully this post will help someone before they fry their saw. Starting from scratch with a 50mm cylinder with more conservative porting.

 

[grizz55chev]

View attachment 1001839

Latest update: toasted the cylinder. The saw went from running rich to running extremely lean in a cut. Not sure how it happened or what went wrong. Lowered the metering arm the smallest amount under flush. The saw was running better but very sensitive to the slightest adjustment on the carb. Hopefully this post will help someone before they fry their saw. Starting from scratch with a 50mm cylinder with more conservative porting.

Vac and pressure tested after the build?

 

[reed1517]

Vac and pressure tested after the build?

Passed both perfectly

 

[grizz55chev]

Passed both perfectly

Carb kit? Maybe stuck needle!

 

[reed1517]

Carb kit? Maybe stuck needle!

Did a rebuild and then a new carb. Original post has everything I tried to fix the excess fuel.

 

[grizz55chev]

Did a rebuild and then a new carb. Original post has everything I tried to fix the excess fuel.

Excess fuel will not burn your piston, lean run will though in a heartbeat.

 

[reed1517]

Excess fuel will not burn your piston, lean run will though in a heartbeat.

Yeah. It was in my earlier post. It was very rich then went lean quickly. I was just curious why it would do that. Very sensitive to carb adjustments.