Need help!

[TimotaLT]

So I'm having problems and can't figure out what's going on. I was out riding and ski just died and wouldn't start back up, got it back to the trailer and no spark. Checked some things and still no spark. Thinking it was cdi I got a new one and installed still no spark, after going thru everything it ended up that three of the six rivets that hold the flywheel together broke and rattled around and damaged the stator. Got a used known good stator and a flywheel installed then when I got to the lake to test ride it ski ran but it had no mid range if you grabbed the throttle full, it would only rip if you feathered the throttle. Nothing else during this fix was touched so I was thinking maybe just by coincidence the carbs need a good clean so had them rebuilt and cleaned then put back on the ski and test rode still running bad same issue and tried tuning the carbs for a good while couldn't really get a change of running better. Tried a set of carbs off a friends ski and test rode and it was almost back to normal and at this point no sure what's going on with these issues if anyone could chime in?

 

[wmazz]

How is your ski set-up? How long since the last rebuild. Did you check the crank
for runout before installing the other flywheel.

You may have rebuilt your carbs with less expensive parts, another possibility is
the carbs you got from a friend still had the adapter plates on the carbs?

Does your friends carbs have a different set-up.

Are there any holes on your pulse line?


Bill M.

How many carb gaskets have you replaced?

 

[TimotaLT]

The ski has a head, factory pipe, vforce reeds and the engine was last rebuilt about 4 yrs ago. The carbs I borrowed are basically the same and from another ski with similar set up and the lines are good no holes

 

[MADMAT]

Man I just had a similar issue and it was because my flywheel had sheared the key and spun a tad on my crankshaft. I went through my carbs and checked everything else and as I was going after my stator I figured it out! Brutal!

 

[MADMAT]

Oops nevermind I read it again.....I see you did those.....I had read the first part and was like ooh ooh it might be the flywheel!

 

[bored&stroked]

Almost back to normal means not normal so the friends carbs didn't fix it. I'd check compression, and the reeds, and then think about a different stator since the replacement was used just to double check.

 

[TimotaLT]

And we weren't sure about where to set the stator, stock setting or advanced?

 

[TimotaLT]

Maybe the stator I'm using is not good would that be a cause of these issues maybe? Since at first all I did was change the stator and the flywheel and it had the problem?

 

[wmazz]

when I got to the lake to test ride it ski ran but it had no mid range if you grabbed the throttle full,
it would only rip if you feathered the throttle.

Sounds like it is lean.

so had them rebuilt and cleaned then put back on the ski and test rode still running bad same issue
and tried tuning the carbs for a good while couldn't really get a change of running better.

Generally speaking, if you take apart the carbs a you don't find anything,
you should look at the gaskets and gasket surfaces. Yamaha's have many
common leaks.

Tried a set of carbs off a friends ski and test rode and it was almost back to normal and at this point
no sure what's going on with these issues if anyone could chime in?

If everything is the same on both carb sets, the carb base gaskets may
be different and leaking.


Bill M.

You also replaced the pickup coil?

 

[MADMAT]

Oh man a bad stator or CDI can really cause diagnostics issues.....especially a used one that is not 100% KNOWN to be good...set it stock for troubleshooting.

 

[TimotaLT]

I just am so stumped how I changed the flywheel and stator and the problem with running right started and didn't touch the carbs during the fix. Could it be the stator and I went through all the hours of chasing something else? It's just weird how changing the carbs tho got it close to how it ripped before

 

[wmazz]

Did you see this thread , where I attached information on using a
peak voltage tester to determine the condition of the stator, pick-up
and cdi.

If you are interested in building the tester, I have Yamaha test specs.

Bill M.

Peak voltage testing is more reliable than an ohm test

 

[kevbo]

The ignition timing is probably retarded compared to your old setup. This will make the pilot circuit act leaner plus hurt throttle response. Your carbs were probably on the lean side. . I tried retarding timing 3 degrees once, it only affected part throttle tuning and response. Top end was the same. I cut a window in a spare cover so I can check timing.