Yamaha TRX850 Enthusiasts Forum

bike was running well then pipes got red hot now wont start when't to check the timing removed timing plug bolt when I removed the strait plug about three litres of fuel and oil mix pored out what do I do now?

1a. Ditch the stock fuel tap and replace it with an aftermarket item that has a true 'off' position.
1b. Replace the float seals in both carbs.

The combination of leaky fuel tap and leaky float seals, along with the unfortunate coincidence of an inlet valve being open, are the cause of the fuel in the oil.

2. Dump all the oil and replace as soon as possible.

3. Hope that running the engine with fuel diluting the oil hasn't destroyed any bearing surfaces.

in addition to the above

you should clean the carb float bowls. The float valve should stop fuel coming through the carbs when the bike is not running but there could be dirt under the valve or the vale could be worn

thanks for the replies Does that mean the fuel in the oil made the bike run red hot and rough then not want to start or is the timing an issue to cheers

You should also check your fuel pump, when the diaphram fails, it allows fuel to enter a cylinder via the vacuum line.
I have had to replace the oil twice to ensure the fuel was completely removed.

al22 wrote:thanks for the replies Does that mean the fuel in the oil made the bike run red hot and rough then not want to start or is the timing an issue to cheers

If it was previously running OK and you have not made any changes to the engine, then the timing will not be altered. How could it be?