Yamaha 60 cooling issue

[Wightdiver]

Hi Forum

I have a 2 stroke auto lube Yamaha 60 ( best guess is early 90s) which is experience a cooling issue.

The flow from the water jet is very week, it just drops vertically from the jet rather than gush out at an angle, higher revs increases the flow rate but still very week. There is plenty of water flow from the exhaust ports at the top of the leg. I have tried disconnecting the small flexible tube that runs to the water jet nipple and blowing back down it but couldn’t, is there some form of one way valve in the system?

I have checked the impellor which is in perfect condition.

Any thoughts, observations, ideas most welcome.

[BumbleAbout]

I have had similar issues on my Yam 50 - I just disconnected the flexible water tube inside the cowling and used a piece of wire (strimmer line also works) to get rid of the sand blocking the nozzle.

[zookeeper]

its dirt in the tube, had the same problem and now have a tell tale like a jet wash!

[camtheribman]

I ran mine in a barel of vinegar, 13p a litre from tesco.

[Wightdiver]

Guys

Many thanks for your prompt replys, I will give it a go tonight.

[spartacus]

Glad you got it sorted. Also worth checking the thermostat. My Yamaha 40hp, used to get a build up of salt here at the end of the season and needed a good clean and flush.

[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.

[Wightdiver]

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.

Hi Bernithebiker

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.

Andy

[bernithebiker]

Wightdiver - I just ran my engine again in a barrel of water, and the telltale was very limp.

Using a piece of fine wire, I gently probed up the telltale spout, and almost immediately, the jet became much stronger, back to normal.

So I wouldn't worry, I reckon that's both our problems fixed pretty easily.