Seized 587 Plug Change

[Butch 587]

I may have made a fatal error changing plugs was running NGK and running good changed to Champion N4C made it about 500 yards and seized the motor the plug change was the only variance make from normal prior operation..
Just wondering why this went so wrong ...

Thanks..

 

[LouDoo]

The first thing I would do is pull the plugs, ground the spark plug boots, squirt a little oil down the spark plug holes, then see if the motor will turn over.

Let us know the results.

Lou

 

[Butch 587]

Yes it turns over but the plugs are as gray as my hair, looks like aluminum deposits ...

 

[Dr Honda]

The N4C crosses to the B7ES. You should have a resistor plug, but the plug wouldn't have caused the engine t seize. Since you have a 587 engine... I'm going to assume it's older, and it probably just lived its life.


What kind of oil have you been using?

 

[LouDoo]

Sounds like you burned the tops of the pistons, I thought that the Champions might have longer threads, causing the plug to contact the piston. From what the Doc says probably not.

Check the compression, if you have good compression, 120 or better both cylinders.

Will it start with the NGK plugs? Just see if it starts, don't leave it running.

Lou

 

[Dr Honda]

Yep... gray isn't good. As you suspect... that's probably aluminum, and as Lou said... the pistons are probably roasted.

 

[Butch 587]

The compression is low about 60 lbs in the back hole... Top end is shot...
Tony I have been using Mercruiser oil ....
Anyone have a reasonable parts source for a 587 kit?
What really get's me mad is I just sold a sweet 150 lbs in both holes 717 to a neighbor.. for 450.00 Duuuhh....
I have a probably decent single carb 587 with about 130 lbs in both holes I can drop in but I will still need to rebuild the bad 587I also have a complete 2 carb 717 setup on ebay for no reserve if anyone is interested.. I have collected 4 skis and a few extra motors in the last few months and need to clear out some stuff..

 

[Dr Honda]

Tony I have been using Mercruiser oil ....

Welllllll................. There's your problem. That's a TC-w3 oil, and that's a HUGE No-No in the Seadoo world.

I think the most convenient place to get a top end is from SBT. (but not the cheapest) They will get you pistons, rings, bearings, gaskets, ans swap your jugs for about $400. If you have a good local shop... they will probably have the best price.

 

[Butch 587]

Ok now I know this, what is the correct oil to run ? Also what is the correct oil for my 1990 Yamaha waverunner 650 before that blows up too

Thanks again for the help guys.

 

[LouDoo]

I run Quick Silver PWC 2-cycle mineral oil, it's readilly available (WalMart). On the bottle it says approved for Waverunner, Seadoo and Polaris. So you should be O.K. running this in you Yamaha also.

Lou

 

[Dr Honda]

Any oil that is certified as API-TC is what SeaDoo specs. TC-w3 doesn't protect well enough.