SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: challenger on June 13, 2009, 01:56:24 PM
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my oil cap fits snug but when i slam the gas it goes 4 feet in the air is there something going on or bad oil cap
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You need a real OIL cap and not that 710 cap you have there. ;D ;D ;D
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ok thanks
but whats a 710 cap anyway
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Maybe it could be an issue like I had...I had a twist in breather and I slammed on the gas in my nordic and I heard something sound like a bottle rocket...looked back and the breather was like 10 feet in the air...was told I have a lot of blow by...how old is the motor?
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i got it as a repo l do not know chit about it
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No vent in a valve cover will not work..
The best fix IMO would be to go pick up a Chrysler style breather and run a vent hose to the scoop....Like so.
http://www.summitracing.com/parts/MOR-68780/
Ugly but functional ;)
GT
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Can't really tell by the picture but are there any breathers or pcv in those valve covers?
I had a very similar issue with my motor when I changed valve covers, kept blowing the front and rear lifter valley seal on the intake manifold. Ended up having to put a tall breather on each valve cover in the front with baffles screwed in underneath to keep oil from blowing out.
Like this...
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fwww.supermotors.net%2Fgetfile%2F726876%2Ffullsize%2Fimg_0031.jpg&hash=d5e86e5d02a157bf386460f572b0ee966062b5b1)
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so i sould just drill a hole in the scoop then hook the holes up
and what about the other side it does not blow off sould i just leave it or do the same
thanks for the help guys
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im not sure what this has im just learning how to work this boat from this web site
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so i sould just drill a hole in the scoop then hook the holes up
and what about the other side it does not blow off sould i just leave it or do the same
thanks for the help guys
You could just get a couple of these badboys. :-\ http://www.summitracing.com/parts/MRG-2079/
Best bang for the buck IMO.
Any one else got anything?.... I would recomend a puke tank, but this is less expensive and may work, you would reuse the breathers with a puke tank anyway, so no backtracking... ;)
GT
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I don't mean to keep throwing cheap fixes at everybody, but sometimes they work the best.... :thumbup:
challenger, not trying to make you out to be a cheapskate ;)
sorry if I come out that way.
GT
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I dunno...I bet if he put a breather on the oil cap side that would fix it. Maybe a leakdown test is in order..that sounds like a lot of blow by or something??
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Iam a cheapskate ;D ;D but whats a leakdown test
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Iam a cheapskate ;D ;D but whats a leakdown test
A leakdown test will determine the overall cylinder to ring sealing integrity, done with a leakdown test manifold, it will tell you what the rate of leakdown each cylinder is. It is one step beyond a compression test.
Most automotive repair shops will do it. Sometimes best to find a buddy with a tester to do it, I'm sure someone on these boards could help you out for a fee/some beer ::)
GT
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what's the tool called and how much is it. would I ever use it again or can it be used for anything else . I'm just trying to get this boat ready for the river and all this little chit started popping up and I don't know tick about motors.
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what's the tool called and how much is it. would I ever use it again or can it be used for anything else . I'm just trying to get this boat ready for the river and all this little chit started popping up and I don't know tick about motors.
leak down tester LOL... ;D
GT
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I have a pcv valve on mine... It should make a difference in lowering your crank pressure when you step on it.. You need to get a pcv valve grommet that goes in your valve cover... It will replace one of your breathers... Next get a pcv valve. Then get some hose... should be 3/8 I think... This will go from the pcv valve to the bottom of one of your carbs.. There should be a port there some where... If all else fails take your boat to autozone or checkers and have them go outside and they should be able to show you what you need..
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ok thanks
but whats a 710 cap anyway
Had to reply on this one. If you look at your cap upside down it says 710(OIL backwards). GAWnCA was trying to make a funny. He's good like that. Good luck with your problem. I have no ideas for ya. Sorry. ;D
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710.... oil..... HA HA HA ;D Oh and by the way the pcv valve thought is just a thought... What do I know I'm just a truck driver.... lol.. Good luck
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I have a pcv valve on mine... It should make a difference in lowering your crank pressure when you step on it.. You need to get a pcv valve grommet that goes in your valve cover... It will replace one of your breathers... Next get a pcv valve. Then get some hose... should be 3/8 I think... This will go from the pcv valve to the bottom of one of your carbs.. There should be a port there some where... If all else fails take your boat to autozone or checkers and have them go outside and they should be able to show you what you need..
The PCV valve is not a bad thought, just bear in mind, once the engine hits about 4,000 RPM, it does nothing at all (vacuum levels are too low)...
GT
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You can get a cheep leak down tester at Harbor Freight for about $40.00 (the one I bought didn't work properly) or you can get a good quality one from Matco, Mac, SnapOn for about $150.00.
I have one and I could probably get over to help you out after fathers day (I've still got the engine out of my boat and trying to make it to Big River next weekend).
crewchief
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You bringing the Boss and Rebecca?
Ray
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You bringing the Boss and Rebecca?
Ray
That is the plan. The Boss is not happy that her boat is still apart ;D
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That is the plan. The Boss is not happy that her boat is still apart ;D
Yeah I wouldn't doubt that keith...hope to see you guys in br next weekend!
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my oil cap fits snug but when i slam the gas it goes 4 feet in the air is there something going on or bad oil cap
IMO you can't (until laws prohibit ;) ) Have too big enough Breathers on these motors but to blow a breather like you describe suggests alot of crankcase pressure , could be a number of things Tom
Crankcase pressure that is sufficiant to "blow" a valve cover cap is Pure and simple "abnormal" , An N/A Jet boat motor such as this is a 5k + or - rpm motor , as a general rule this type engine should run forever with a PCV valve on one side and a large atmosphere breather on the other or simply two moderate size breathers (one on right and on left) , with little to no "blow by or residue". Blow by from excess crankcase pressure can be resultanat from "mis build" , including but not limited to piston to wall clearance, ring clearance and poor or improper ring seating ,stuck rings , burned piston , etc etc issues. Granted Pan Vac systems and Puke tanks will aid and help "control' or "mask" some of this but they shouldn't be neccesary as a rule . I would do a wet and dry compression test and cylinder leakdown myself Just my 02 Tom
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From what I was told its a good indication of bad rings or valves aren't seeling!
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IMO you can't (until laws prohibit ;) ) Have too big enough Breathers on these motors but to blow a breather like you describe suggests alot of crankcase pressure , could be a number of things Tom
This is not a common problem with a solid roller high rpm motor. Some will weld a bung in their exhaust and run a hose from valve cover to the exhaust so the blow by just fly's out the exhaust on both sides. I went the more expensive way and ran a vaccume pump witch sucks the blow by out of the motor and spits it in a catch can and is adjustable and you'l see a 20 hp gain with the pump style. my old motor would spit oil out both k&n breathers in the valve covers and it would make a mess and piss me off.it reved about 6600. I'm talking about motors pushing 5000 2 8000 rpm's tho. I don't think that is your case tho. I'm not sure if this will help you but Im letting you know that crank case pressure in not uncommon, and on most big hp motors they will run one of the two set ups Iv'e described. The vaccume pump is the best way to go in this case. i will post a picture of my next post of what it looks like. all said and done i spent around a 1000 or 1200 for the complete set up which is why most just dump out the exhaust. In your case it could be a ring problem not sealing and pushing oil fuel or exhaust into you valve covers and tho only place for it to go is out the valve cover breathers.
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Ill have to post tom comp just got a std! :banghead: