I have a Mudbuddy 35hp Vanguard, Q muffler, Mikuni carbs. Its about 10 years old and about 200 hours. For a while now, i have trouble starting after it gets hot. I have a ten mile run to my lease. In the winter I don't have the problem much but in the summer, after I run there, it will kill when I stop and then will have to cool off before O can restart it. Last time I saw flames come out of the exhaust when I tried to restart it. Don't know if irs a muffler problem, a fuel air mix issue, vapor lock, flooding or just overheating. Any insight and help this issue would be apprecitaed.

Sounds like its running rich, check the carb settings

yup I would say its loading up with fuel. What do your plugs look like.

I'll pull the plugs when I run it nex weekend and see. I had replaced the durng the season as they had become very fouled. Since then the engine was tuned up professionally and had a lot of other work done to the engine. The mechanic points to the q muffler and that it lets a lot more air in. Also thinks there could be a stale fuel issue. The fuel is aboit 4 months old. And the engine has only been run twice since February. He recommends running some hi octane the next trip to help clear out the carbs. I'll try that oil senor trick as well of it happens again. Thanks for all the feedback.

So deadbird8 I'd say you were right about the oil pressure sensor. I went out and reproduced the engine not starting, tried to start it with the sensor plugged in with no luck, pulled the wire off to the sensor and it started right up. Did that two more times and each time as soon as I unplugged the sensor the engine would fire up. So, i'll try repalcing it but good to know I can unattach it and get the engine to start.