2006 Yamaha VX110 knocking/tapping

ncSandlapper

Recruit
Joined
Apr 11, 2020
Messages
1
Jumped on my ski yesterday for the first time since September. Started right up and sounded normal. Idled out of the marina to the ICW and when I throttled up, no power. Idled back. Pulled the seat and ran it at the dock, and there is a definite knocking or tapping in the engine. I pulled all the plugs (which were changed last Aug) and they all looked good. Oil is also good level and looks good. I have a good basic knowledge of engines but that's about it. When I get it home I'll do a compression test as a next step but I was hoping for some other ideas about what to check for/possible cause...sticking valve?? Thanks for any advice.
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,286
Hi. I have the higher powered version of this engine. Not much to go wrong with them...apart from the following things;

These are known to have ecu shorting issues and cause an injector to stay open and over fuel. Almost causing the engine to hydro lock at its worst and at best cause poor running and throwing fuel out the exhaust in a dangerous way.

The other really well known one is with the oil. They hold just over 4l of oil, but if changing the oil the conventional way without cheating you will only get about 2.2l of oil out the collection tank at a time. Some folk don’t pay attention to how much actually came out and read that it takes 4l...and throw 4l into it, without realising they now have 2l too much in it. It then throws oil up through the air filter and into the throttle body. Can damage the whole thing on occasion.

on a similar note...some folk dip the oil cold and think there is no oil in it...not knowing it’s a collection tank and the engine needs to be running for a little before you get a level in the tank. They add oil...see above.

orher thing is that they just plain don’t like to idle for long. The plugs foul extremely easily on these like that.

Although you may already know all the above by now...it’s still perhaps likely that a previous owner didn’t and may have damaged the valves. Hopefully not.
Also worth knowing that they do sound really rough at idle and on the trialer on the hose. Perfectly normal though. These 110 MR1 engines haven’t been the most popular choice for the jet ski hire market for a decade and a half for no good reason. They literally can go for 1000’s of hours with just oil changes. All the best
 
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