97 VMax Issues after Exhaust Gasket

[sodakota]

I have a 97 Vmax 500 that runs very well until today. My son was on it and he said it just stopped. When he looked under the hood the exhaust gasket was broke. I put the gasket from my 98 Vmax 600 and tried to start. It will not stay running. What am I missing. Could a failed exhaust gasket foul plugs instantly? Did it take out something else?

With the choke on full, we can get it to run although roughly.

Help.

[dab102999]

Change the plugs and see. If you have to run full choke sounds like you got some dirty carbs going on.

[jimfsr]

I would venture a guess that whatever made the engine quit, is what blew out the gasket. I would do a comp. test. If it got hot, it may have melted a piston, not enough to stick it, but enough to loose compression, or add so much resistance that it needs extra fuel for the good one to sustain it. The added heat would also potentially take out the gasket.
Are you refering to the donut between the y-pipe and chamber? Or the gasket between the y-pipe and cyl?

[uperjim]

When my 97 vmax had dirty carbs(plugged idle jets) I needed to have the choke on to idle and accelerate witthout a stutter.

My guess is that is the problem--cheap fix. If it wasn't running right ---especially when the engine was cold those vamax's backfire all the time and when they do that they blow out those donut gaskets. Those donut gaskets are a bad design anyhow and I usually have to replace mine every 1-2 years---they wear due to rubbing and then they can easily blow out and I have yet to find an aftermarket replacement and Yamaha ones are expensive.

[dab102999]

SPI's are good gaskets and are a lot cheaper, I got mine through highperf.com