M38 idle issue

Rick_L · Post by **Rick_L** » Sat Aug 19, 2017 5:21 pm

My M38 recently developed an idle issue. It will idle fine for a couple of minutes, and then begin slowly running rougher until it stalls. I've found that if I disconnect the crossover vent tube to the carb, the problem goes away. The vent tube is clear, as are both of the ends where it connects. I have anther vent tube that I tried in its place, with the same results. This has me stumped as I believe the venting is to prevent a vacuum from developing in the bowl. If the tube and the connections are clear, why does this occur?

OKCM38CDN · Post by **OKCM38CDN** » Sat Aug 19, 2017 7:14 pm

Check the tube inside the crossover tube, there is about an inch or more inside the crossover, it connects then bends up an into the crossover... possibly got a bug in there. Use a small piece of flexible wire to snake in and see if it is clear...

Rick_L · Post by **Rick_L** » Sat Aug 19, 2017 7:34 pm

I'll try running a pipe cleaner soaker in carb cleaner through there. I was able to blow through it when the tube was connected.

OKCM38CDN · Post by **OKCM38CDN** » Sat Aug 19, 2017 7:45 pm

Just thinking of this, try taking the gas cap off. You might be suffering vapor lock...

Rick_L · Post by **Rick_L** » Sat Aug 19, 2017 8:00 pm

Tried that already.