• Welcome to Jetboaters.net!

    We are delighted you have found your way to the best Jet Boaters Forum on the internet! Please consider Signing Up so that you can enjoy all the features and offers on the forum. We have members with boats from all the major manufacturers including Yamaha, Seadoo, Scarab and Chaparral. We don't email you SPAM, and the site is totally non-commercial. So what's to lose? IT IS FREE!

    Membership allows you to ask questions (no matter how mundane), meet up with other jet boaters, see full images (not just thumbnails), browse the member map and qualifies you for members only discounts offered by vendors who run specials for our members only! (It also gets rid of this banner!)

    free hit counter
  • Guest, we are pleased to announce that Hydrophase Ridesteady is offering an extra $100 off for JETBOATERS.NET members on any Ridesteady for Yamaha Speed Control system purchased through March 7th, 2025. Ridesteady is a speed control system (“cruise control”) that uses GPS satellites or engine RPM to keep your boat at the set speed you choose. On twin engine boats, it will also automatically synchronize your engines.

    Click Here for more information>Ride Steady group buy for JetBoaters.net members only

    You can dismiss this Notice by clicking the "X" in the upper right>>>>>

Oil on top of spark plug and milky oil

jattard

Active Member
Messages
8
Reaction score
1
Points
40
Boat Make
Yamaha
Year
2019
Boat Model
AR
Boat Length
19
Helping a friend with an 2017 AR195. Driving at WOT had smoke, loss of RPMs and small oil/fuel slick in exhaust water. Drove it back to dock just fine, no symptoms. Cylinder #1 had oil on the top side of the plug. Also, noticing milky oil in fill cap, dipstick, etc. It would seem the valve cover gasket has issues for the spark plug oil, but cant understand why milky oil too. exhaust manifold or head gasket would need to fail to mix water/oil. TIA
 
Where are you boating at?
How long has he owned the boat?
Does he do his own up keep?
Do you notice any extra water under the engine?
 
Has it ran much so far this summer?

How many hours are on the engine?
 
Initially sounds like some gaskets that need to be replaced.
 
Have there been any overheats?
 
does he know not to run the hose with the engine off when flushing it and not to tow it over 5 m p h if it has to be towed in and as @swatski has recommended if you tow it have the reverse buckets UP in forward.
 
Where are you boating at?
How long has he owned the boat?
Does he do his own up keep?
Do you notice any extra water under the engine?
Michigan
4 years
Yes, he performed oil change and is aware of the proper hose operation.
No extra water in engine bay.
 
Has it ran much so far this summer?

How many hours are on the engine?
Probably 10 runs this season, after the spring oil/spark plug change. Thinking the event with smoke and oil slick was the trigger for milky oil.
 
225 Hours on boat
 
Dealer said cracked head! Known issue with the engine. I have never heard of this being a known issue. Trying to get pictures of the damage...
 
Last edited:
Dealer said cracked head! Known issue with the engine. I have never heard of this being a known issue. Trying to get pictures of the damage...
Any pics? Update on this? Thanks
 
Back
Top