Engine trouble

[Goinfishin]

I bought a second hand yamaha 9.9hp just over a month ago I have used 4 times, it has ran fine with a strong flow coming from the tell tale.

I mostly use the SIB for trolling (fishing) at a slow speed about 3-4 mph and open the throttle every wee while as its a 2 stroke.

Was fishing loch awe yesterday and the engine started to make rattle/vibration sound it was not very loud and we thought it was our trolling downrigger cable vibrating. A few minutes later the engine got a little smokey this is when my brother noticed the tell tale had stopped flowing.

We stopped the engine a rowed ashore, I know that tell tail failure is usually impeller failure but my main concern is how long had it stopped coming out. I'm right handed and cannot see it as it exits on the right side.

I removed the cowling as soon as we had stopped the top of the cylinders where not hot just very slightly warm to the touch.

My main worry is if I've caused any damage to the engine rings bore etc.

Any thoughts from the more experienced would be appreciated.

[chewy]

Might be best fitting a new impellor and see how/if it runs?

[hobnob]

Originally Posted by Goinfishin

Any thoughts from the more experienced would be appreciated.

Same happened to me on the Thames yesterday. Yamaha 8 hp 2 stroke on a SIB. Lost the tell-tale with 4 miles to go. Took cowling off and monitored temperature, but kept going as it seemed to run well and cool.

Turned out the tell-tale was blocked. Cleared it with a 2mm drill by hand. The engine kept cooling - most of the circulated water exits from the centre of the prop.

Having said all that, the manual says STOP if no tell-tale!

[spartacus]

My main worry is if I've caused any damage to the engine rings bore etc.

There's no point worrying about it now. As suggested - you felt the engine block and it was warm, so hopefully no long-term damage. Go ahead and replace the impellor. Also check the tell-tale, run a length of strimmer wire up it - to check there's no blockage. I'd also take it off the thermostat to check it's not jammed in a closed position. Good opportunity to clean the thermostat housing.

[Jizm]

Originally Posted by spartacus

There's no point worrying about it now. As suggested - you felt the engine block and it was warm, so hopefully no long-term damage. Go ahead and replace the impellor. Also check the tell-tale, run a length of strimmer wire up it - to check there's no blockage. I'd also take it off the thermostat to check it's not jammed in a closed position. Good opportunity to clean the thermostat housing.

Agreed, simple job and not expensive either, motor will probably be fine.

[jyasaki]

Might be worth doing a quick compression test. Should tell you if you've scored the bores or lost some rings. If you have, it's not worth changing the impeller at this time (assuming that was the original problem.)

jky

[Jizm]

Final outcome here then?