VF500 Steam from Exhaust -Help!

Hello. We would really appreciate any help/advice regarding our VF500F2 Interceptor. The problem is that there is steam coming from the exhaust. On investigation it was noticed that there was water in the inlet valve port on the front cylinder (number 2). The head was removed and checked. No sign of damage, a new gasket was fitted, put together, fired up and there was still steam coming out the exhaust. A new front cylinder head was purchased and fitted. Engine stared and ran well. When up to temperature staem started appearing friom the exhaust again. It was then thought there must be a problem with the rear head. We could not source a new rear head so a full second hand engine was purchased. This was said to be running well. The rear head from this was removed and fitted to the engine. Fired up. Ran well. But when up to temperature steam reappeared. Assumed new head might be at fault so front head from donor engine was also fitted. Ran well but when up to temperature steam appears. Blue Devil crack and gasket sealant has been tried. Appeared cured. But next day same problem.
Any suggestions will be gratefully recieved. Thanks. Colin

 

Could be a bunch of things, you've eliminated the head gasket though, which is good.

I would refrain from running the engine any further until you've figured it out. You don't want to hydro-lock. There could be a a leak in the water jacket.

You're finding water in the cylinders? Is the coolant level dropping? What do the spark plugs look like on each cylinder? What does the crown of each piston look like?? What does the oil look like?

More info, please.

 

Hi
Thanks for replying. More info to follow shortly......

 

Hi. There's no water getting to the cylinder. Plugs and piston are fine. Bike can sit for weeks and no water gets there. Will start fine and run well but when up to temperature steam comes out. Oil is fine. Coolant level drops a little.
Any ideas/suggestions?
Thanks

 

You appear to be of above average mechanical ability.

1. No water getting into the oil?
2. Losing coolant?
3. Were the head gasket mating surfaces checked to ensure the cylinder to head mating surface was sealing properly?
4. Leak down test performed, not a compression test, a leak down test

The multiple head replacements with varying components would indicate to me the problem might not be in the cylinder head. Leak down test would be my first step.

 

Is this engine running with the stock OEM or a modified/open air intake? If modified or open is there any coolant lines or fittings in the vicinity of #2 intake that might drip or spray.

What exhaust system are you running? Maybe there is rain water collecting in there that only steams out when the motor is hot, and the water in #2 intake was just a coincidence. It would take a huge amount of water in the intake to manifest as steam in the exhaust, and the coolant level would be dropping like a rock.

What do the plugs look like--you said they were fine, but that's not a description. Either dark and sooty or dry/ashy, perfectly white insulator, spotty insulator, etc. Are they all identical description or is one different--it should definitely be different in #2 if you run it up to steam temperature for a bit and then kill the engine and pull the plugs.

 

Hi. On reading the replies our next step will be a leak down test. We will buy the necessary equipment on ebay and carry out the test. Will update the furum with the results.
Thanks

 

Are the crowns of any of the pistons shiny and clean?

 

Interested to see the results of the test. Just knowing the engine is mechanically tight will limit the possibilities and cut down the wasted time and effort.

 

Hi. Got a leak down test kit on ebay for £20. Looks good. Weather is a bit chilly at the moment but will carry out test soon. Is it better carrying out the test with the engine hot or cold? Will check plugs soon and piston heads will be checked without removing heads with an endoscope. Will let you know results of test when we get them.
Thanks

 

Testing hot is better as there may be a crack that only opens when hot.