Strange engine noise 1998 Venom 200

[champman]

Just bought boat has a 98 200 Venom on it had water pump and gear oil replaced also new plugs. Mechanic said there was some metal on the upper plug magnet. Ran great at the shop. Got to lake and boat had a low idle and spit but ran great off idle, at idle I noticed a strange sound coming from enging it was kinda like a light knock type sound but went away when you raised rpms. Could lower unit make a noise like this since he said there was some metal on magnet. Boat sounded great on the hose but at the lake it ran terrible at idle and made this noise. any ideas.


Modified by champman at 5:39 PM 1/31/2008

[THE WITCHDOCTOR]

What plugs they put in?

[FishMoore]

I have a 97 200 venom. It has a light knock noise you hear at idle, i was told that the oil pump can make this noise.
Not sure though. I never had a moments trouble out of mine, so i did not worry about it much.

Not sure about the idle problem.

Goodluck, Hope it's nothing serious

[Lockjaw]

Lower unit is probably going south.

Do you only hear it in gear? If so, get it fixed now.

[ChampioNman]

Have him pull the lower off and check the shift rod height adjustment.

[champman]

Not sure what plugs he put in, Runs great off idle, just concerened about the strange noise at idle as soon as rpms increse it goes away, he checked the magnets under the flywheel to see if any were loose, all ok. he was going to look at it again on monday. I hear the noise when motor is in nuetral and in gear, low rpm only.

[champman]

Shop said that the knocking was there off idle I just couldnt hear it as well because of engine noise. Did a compression and leak down test all ok. I gave the ok to tear down to find source of knocking didn't want to take a chance on it comeing apart on the lake. Found #1 and # 6 cylinders scoured, the noise I was hearing was piston slap. It's a wonder it didn't blow at the lake. He will let me know tomorrow what he finds that caused this. Also said # 1 had slight rust where piston was sitting the previous owner didn't use boat much .

[ChampioNman]

$2-3K to fix. Doubt it would have gone south if decarb had been done. I see a ton of scuffing in the cylinders. All normal for customers that don't maintain their motors. Tell your tech to up the #1 carb .002 HS jet when the gets done.