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Yamaha Petcock. Flooded Motor? Gas in Oil?

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I was having trouble with a leaky OEM petcock so I swapped it our for the Raptor petcock which worked nicely. Problem is I forgot to turn it off overnight and I guess my carb float failed this time. I noticed gas dripping off the rear axle area actually which I thought was odd. I traced it and found it leaking out the bottom of the air cleaner box so I figured I had/have a bunch of gas sitting on top of the piston. Like a dumb@$$ I went to start it and luckily the starter just clicked and nothing happened (separate issue?). I immediately wondered if there was any gas in the oil so I took the dipstick out and smelled and there didn't seem to be any gas smell (but I have a hard time telling sometimes). I leveled the bike and let it sit to check the oil level - it was just a hair LOWER than when I changed the oil about 1500miles ago - would it be safe to say then that there's no gas in it? I run Silkolene synthetic 10W-40, and it still looked red (although a little dirtier now), but I don't know how much gas it'd take to turn it's color. Should I just change the oil and not risk it? There's only 7500miles on the bike, will gas leak past rings that new?

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You haven't said how you got the fuel out from the cylinder, the click you heard is from the piston hydrolocking. If you haven't taken the sparkplug off to drain the cylinder, fuel has found it's way into the crankcase. I'd take the sparkplug off, cycle the piston by hand a few times, blow the cylinder dry with an air nozzle and change the oil.

Then I'd replace the petcock with a stock one since the odds of me forgetting to shut off a manual petcock are much better than the odds of a stock one failing.

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Not sure about the clicking sound,when my pc and float needle failed my starter did nothing and gas was in oil as well as hydro locked so pull the plug turn over by hand so if gas is in there it won't shoot all over the place.if gas is there,I changed the oil 2 or 3 times.hope you don't have to do all that.

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the clutch shears the oil reduces and viscosity breaks down. Suzuki does not care how long you bike lasts. did you read the expected logevity in the manual? drain the oil, pull plug and crank by hand, dry the plug and cylinder, refill the oil, reassemble. petcock is your call.

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Pull the spark plug, blow out the gas, change the oil, and learn to shut the fuel off.

Oh and dont listen to what Suzuki says, you are due for an oil change.

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1000 miles between oil changes. abide by it and have a long lasting engine.

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Huh, updates don't seem to be working for this, never saw your guys' replace, THANKS!

Yeah I figured out the starter was going into overload due to a hydro-locked cylinder. Never saw any sign of gas in the oil (didn't smell like gas and the level in the tank didn't rise a hair) but I went ahead and changed it anyway. But 1500 (or Davenjw - 1000!), that seems crazy often, especially at $42 a change (Silkolene Pro 4 SX 10w40, K&N filter).

I did put a rag over the hole before I pumped it but still got sprayed a little, oh well. Kinda surprised nobody mentioned to ground the spark plug cap (a pair of vice grips and a 1/4" extension came in handy for this while holding the clutch and pushing the starter button). How do you guys crank over a 400S by hand?

I put the Yamaha Raptor petcock on it because the stock one actually DOES have quite a problem leaking (don't feel like finding the thread to prove the point) - mine was dripping gas all over. What I don't understand though is why isn't the bowl float taking care of that issue? (BTW - now I find myself going out in the middle of the day, waking up in the middle of the night, etc. thinking I left it on :thumbsup: ).

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That's what I like about vacuum petcocks, one less thing to worry about. The float valve should cut the fuel flow but there's an o-ring that goes bad and it leaks from there. You need to remove the complete valve body held by the small phillis screw to replace it, not just the plunger.

I cranked the piston with the starter too and got sprayed all over :thumbsup: , that's why I suggested doing it by hand. I guess you could roll the bike in gear or remove the cap on the stator cover and use a ratchet.

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Slightly off topic... I need to replace my stock petcock - how does the raptor one fit? I assume its a raptor 660? Any clearance issues? Could you post a picture of how it look/ fits?

Thanks!

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Slightly off topic... I need to replace my stock petcock - how does the raptor one fit? I assume its a raptor 660? Any clearance issues? Could you post a picture of how it look/ fits?

Thanks!

It all depends on what tank you have.

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Slightly off topic... I need to replace my stock petcock - how does the raptor one fit? I assume its a raptor 660? Any clearance issues? Could you post a picture of how it look/ fits?

Thanks!

if the stock vacuum petcock is dripping often the simple inexpensive fix is to remove the backside of the petcock and replace (or turn over) the o-ring on the plunger. Size is 4mm I.D. X 2mm Thickness (8mm O.D.)

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Remember that the stock vacuum petcock will remember to automatically TURN ON your fuel so you don't stall on the road if you forget. Pulling out onto a highway could be a terrible time to find out you forgot to turn ON your gas.

If the carb overflows with the bike off both the petcock AND the float valve need fixing ASAP. If either one does its job their will be no overflow.

Depending on the carb you have the problem with the float valve could be the o-ring that seals the seat to the body or the end of the float valve wearing out. With the bowl off connect fuel and see if it is obvious which one is leaking while holding gentle pressure up on the float. Just enough that the spring in the plunger needle starts to move but not enough to bottom it out in the needle.

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I agree with slowriding, you have a float issue, not petcock issues. I turn off my fuel petcock in the fall, and back on in the spring when i start riding regular again.

Change your oil at 1000 mile intervals and it is really easy to remember when it is due. Use cheap but good oil like Rotella and it is not at all painful.

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I have the stock KLX400SR steel tank.

I'm running the FCR-MX carb so I would prefer installing a manual ON/OFF/RES. Plus that's what I'm used to from my 01 DRZ400E...

Well, then this picture won't really apply to your situation, but here it is anyways:

DSCN0002.jpg

This is the Raptor petcock mounted to a 3.9 gallon Clarke tank without using the spacer, feeding a 90 degree fuel filter looping back to the standard Mikuni carb.

Edited by JMulthaup

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Well, then this picture won't really apply to your situation, but here it is anyways:

DSCN0002.jpg

This is the Raptor petcock mounted to a 3.9 gallon Clarke tank without using the spacer, feeding a 90 degree fuel filter looping back to the standard Mikuni carb.

Looks like a nice setup. I like the clear fuel lines.

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