Thread: Oil filler cap blowing off
06-28-2014, 01:31 PM #1
Oil filler cap blowing off
It only started happening since I overheated and replaced the head gasket. Since then I overheated again(both time my fault forgetting to open the shutoff valve).
The cap is very tight when screwed on. WTF causes this? Possibly boost building in the crank case?
06-28-2014, 01:33 PM #2
you have the oem plastic fill cap?
06-28-2014, 01:50 PM #3
yes. 2 of em now the other one unhinged itself and came out from under the engine
06-28-2014, 02:13 PM #4
I should mention the oil is clear and at the same level. It doesn't smell like race fuel. My plugs are unreadable due to the TORCO.
06-28-2014, 03:17 PM #5
So the filler cap is blowing off, but the dip stick stays in? That's strange.
06-28-2014, 03:52 PM #6
06-28-2014, 05:09 PM #7
Way back when I first joined this site everyone said to ditch the plastic filler cap for a alum one that jerry sold.
Not sure if that's still applies or not. They claimed the cap would come off and all the oil would exit the motor.
I don't see them in Jerrys store anymore so maybe they did not work out??
06-28-2014, 05:18 PM #8
I have never had a problem with the stock cap, but I did have a piston pop out the side of a block a couple of years ago.
06-28-2014, 07:35 PM #9
- Join Date
- May 2008
- Elephant Butte New Mexico
on earlier 4-tecs there is a valve by the oil filter cap..blow off if memory serves..maybe the source of the pressure build up. does the ski have a wirewound dipstick?
06-28-2014, 08:44 PM #10
If you are blowing the oil filler cap specially since it was over heated, sorry to say your getting positive crank case pressure!!! Either your engine breather, our what I suspect is blowby. Compression has got to go up or down
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By exhook in forum Yamaha PWC Performance (4-stroke)Replies: 5Last Post: 08-28-2011, 12:39 PM
By tysonfzr in forum Yamaha PWC Performance (4-stroke)Replies: 7Last Post: 04-25-2011, 11:02 PM
By fasted1500 in forum 4-Tec PerformanceReplies: 19Last Post: 08-26-2008, 06:39 AM
By LS2000 Cop in forum Yamaha ClassifiedsReplies: 0Last Post: 08-14-2008, 03:27 PM
By ph2ocraft in forum Polaris Open DiscussionReplies: 1Last Post: 03-30-2007, 11:25 AM