8HP Yamaha driving me crazy

[minisupercub]

1991, 8HP, 2 strokes, 100:1

Last year was working fine and it was not winterized at the end of the season (my bad), but it was stored in the basement.

Today I tried to start it. It started at the second pull, but smoked a lot more than usual (bluish/graysh), ran underpowered for 20 seconds and stopped.

I tried to start it, I pulled the rope 3o times, but it was not even giving any signs of starting. Strange, it was smoking when I was pulling the rope. Water was coming out, so the cooling system was OK.

Spark plugs were wet, I dried them up, cleaned them and after 10 min I pulled about 10 times and with each pull, I was was seeing the engine was almost starting. Finally started, ran few seconds, smoked a lot, and stopped. Next pulls the engine did not give any sign to start until I clean the spark plugs.

This story repeaded 6 times and 2 hours later I could not feel my right arm and gave up.

When it was running there was visible hesitation, and when putting it in gear and throttle up, there was far less power than normal and it was stopping as soon as I let it idle.

- fuel was fresh, mixed 100:1, half tank
- I tried with gas tank cap opened and closed
- drained the fuel line and pumped fresh gas inside
- fuel filter was filling up OK
- spark plugs were quite wet and dirty after each short "run"

Any input is highly appreciated.

Thanks,
Speo

[greasyshaft]

Cleaning the carburetor takes about 15 minutes on one of those.
Just pull all the jets, clean with carb cleaner blow a bit of air through them and check if they are clean.

Pilot screw setting should be 1-1/8 ± 1/4 (going of the manual for a 8C)

[minisupercub]

Problem solved

Next day it started at first pull and ran like a charm, no excessive smoke, powerful...smooth.

Probably something was stuck in the carb and after soaking in fuel for one day, it freed up.

Indeed, it needs a good cleanup.

Thank you.