Cagiva Raptor 650 (sv 650) engine problem

Jinx · Nitrous Nuisance Joined: 10 Apr 2004 Karma :

the bike in question is a Cagiva Raptor 650, powered by the SV 650 engine. It would not start, either with a good charge in the battery or by bump starting. After repeated attempts it smelt very strongly of petrol. Decided to fit a new battery, spark plugs, air filter and change the oil and filter.

When the air filter was removed the inside of the air box had a puddle of petrol and oil mix in the bottom. Then when the drain plug in the sump was removed the oil that came out looked, felt and smelt like it had been greatly diluted with petrol (very thin in consistency)

There was no obvious sign of a hole in the piston by noise and no visable sign in the front cylinder (cant see the rear cylinder, tank is in the way).

When the bike was last running there was no smoke from the exhaust or obvious noise from the engine.

After market exhaust cans (carbon can company) have been fitted and the baffles have been removed (no change has been made to the jetting).

Any ideas welcome as to how the oil came to be contaminated by petrol. And apart from flushing through and letting it vent, any suggestions as to where we go from here?

Thanks

Jinx
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mchaggis · World Chat Champion Joined: 10 May 2004 Karma :

The rings aren't a good enough seal to stop petrol dribbling through over a long enough time. Is the engine a carburetted version? If so, it's possible that the float valve is sticking so the float bowl is overflowing and peeing petrol into the engine?

Question

Other than that, I don't think I'm much help.
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Jinx · Nitrous Nuisance Joined: 10 Apr 2004 Karma :

it is the carburetted version. Must admit, this isnt something we had thought of - will check.

Jinx

xx
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Sticks and stones may break my bones but leather and chains excite me! Twisted Evil

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

I would say the needles as well. Make sure the petrol is turned off if there is a fuel tap, and not on prime.

All the best

Keith
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PsychoHippy · Jammy Git Joined: 02 Jul 2002 Karma :

Jinx · Nitrous Nuisance Joined: 10 Apr 2004 Karma :

Scotsman37 · World Chat Champion Joined: 17 Aug 2004 Karma :

Do you find any petrol underneath the bike possibly coming out of a rubber pipe while standing the bike upright? If so, then your carbs float valve's button is sticking and so is not cutting off the fuel when the float bowl is full of petrol and therefore it keeps flowing out of the air hole through the air box and down the rubber pipe.

If that is the case you'll need to or mechanic or someone you'll know will need to remove the carb's float bowls and thoroughly clean it out with carb cleaner and a can of compressed air from Maplins to blast the jets and needles, plus the float valve's buttons.

Jinx · Nitrous Nuisance Joined: 10 Apr 2004 Karma :

there isnt any leaking when the bike is standing. The bike wouldnt start and we think that the flooding when we were trying to start it. (which I am hoping is a good sign)
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Sticks and stones may break my bones but leather and chains excite me! Twisted Evil

Jinx · Nitrous Nuisance Joined: 10 Apr 2004 Karma :

I am very pleased to report that the raptor is now running well again. Even managed to get out a couple of times over the weekend and it feels fine.

So to every one who made a suggestion of how to sort it thanks - very much appreciated

Jinx
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Sticks and stones may break my bones but leather and chains excite me! Twisted Evil