Originally Posted by bernithebiker
I have the exact same problem on a Yamaha F100 which is 3 years old and has only done 38 hours. The telltale jet is much weaker than it used to be, but went for a good blast at WOT for a good 10 minutes and there were no cooling problems. Where exactly would the dirt/sand be? Right at the telltale exit, or closer to the engine?
Thanks for any feedback.
Like you I am a bit puzzled. The jet and soft pipe that leads to the jet were perfectly clear, as suggested I used some strimmer wire to poke down the various tubes and then back flushed the cooling channels using a hose pipe rigged up with a lilo onflation adaptor. The water that flowed out of the intaked was perfectly clear, (no sand or sea weed).
It all looks to be OK now, good strong jet but not convinced that i have actually resolved the issue in the long term. I will keep my eye on it.