340 Invader (stumped)

[Vader440]

340 Invader 120 psi on both cylinders good spark both cylinders carbs are clean. Will start for a second or two and then nothing. Ran fine last season. Any ideas would be appreciated.

[mswyka]

Good morning and Happy Thanksgiving.  120 sounds on the low side but should run.  If all is well with the carbs, have you tried removing the exhaust to see if there is an exhaust obstruction?  Could be an intake obstruction also, but less likely.

[Vader440]

I haven't tried removing the exhaust pipe. That's about the only thing left to try. Thank you! Happy Thanksgiving!

[Interceptor398]

Mufflers make great mouse nests.

[Vader440]

I sure hope that's what it is because I'm at a total loss. Thanks!

[Ameritude]

Pulled this out of an airbox about a week ago 😳

[mswyka]

Pulled this out of an airbox about a week ago 😳

Mice have no respect.

[Interceptor398]

No respect!

[Vader440]

Still no go. Compression good, fresh fuel and carbs are clean, spark good, pulled off exhaust pipe. It still only pops a little but will not start. Can you have spark and the CDI still be bad? Flywheel key? Very frustrating. Walking away from it for now. Maybe try again sometime.

[Ameritude]

It's definitely timing of some sort, check the flywheel key, it's rare, but they can sheer. Also check that the bolts that hold the stator on are tight, you can see that they are, by just looking through the holes on the magneto screwdriver. Tightness with a skrewdriver.

[Ameritude]

That was supposed to say check tightness with a screwdriver, dont loosen the skrews, just see if they are already loose.

[Interceptor398]

How is the fuel pump and the lines going to and from it??  Is the primer still hooked up??  I have seen them leaking air and causing this very thing.  Try putting a little gas down the plug holes and "if" it starts watch all the fuel lines for moving air bubbles.  Good luck!!

[mswyka]

It's definitely timing of some sort, check the flywheel key, it's rare, but they can sheer. Also check that the bolts that hold the stator on are tight, you can see that they are, by just looking through the holes on the magneto screwdriver. Tightness with a skrewdriver.

Yes, this is important.  I had an Intruder that frustrated me a few years ago.  I finally found the key had slipped out while putting on the flywheel.  It was stuck to one of the magnets.  Never would have found the problem without pulling the flywheel.

[Vader440]

I plugged off the primer tubes just to make sure they weren't leaking, still no go. I will try to pull flywheel next. Thanks for the info.

[Vader440]

That was supposed to say check tightness with a screwdriver, dont loosen the skrews, just see if they are already loose.

I'll take a look. Thank you!