Help please. 1985 vf500 f

Apparently I have a radiator leak into the engine. Now I have no idea where to start or what to do. I am blowing white smoke out of my bike which is a 1985 vf500 model f and I have done a compression test and all looks well with the head gaskets. the carbs have been stripped down every little piece has been pretty much spit shined with a chem dip then cleaned again after chem dip. It still wants to start really hard. There is a little leak in the carb still in carb four it is either coming from the connecting tube between carbs 2 and 3 or its coming from the float bowl gasket. I have checked both cleaned and securely attached them to the carb but no go. If you need more info just ask I will tell please drop any ideas you have. All are welcome I need this road ready as it is my only mode of transportation. Oh and btw I turned it into a gravity fed instead of fuel pump. The petcock is fine fully functioning. Thanks for checking out my post and any ideas you have.

 

White smoke+loss of coolant ??

Sorry, but you almost certainly have a bad head gasket. or a crack in a head. A look at the plugs should tell you where it is.

You could try re-torquing the head bolts, but it's doubtful that would fix it.

 

Listen to the squirrelman. He knows all the shortcomings of these bikes.

 

Respectfully, yes and no on this point.

Squirrelman definitely has a 'cup is half empty' perspective regarding First Generation V-4s but I wouldn't go so far as to say he is an expert on them.

This said, I do agree that the head gasket may be blown.

 

Yeah leaking head gasket. Simple way to test, is to remove all four spark plugs, if its NOT self evident as to which is at fault, then remove the radiator cap & then use a compression tester or your finger/rubber bung if it will reach & turn the engine over by hand, or geet a friend to rotate the rear wheel with the engine in a high gear.

When it comes up to full compression STOP & hold the pressure. Do this on each cylinder in turn. The leaking one will lose pressure more rapidly than the others, depends on ring condition, valve seats etc. Once you know which head it is, remove it & check the cylinder head gasket & head/cylinder sealing faces. The leak can be very small, but should be self evident.

This will save you having to buy multiple head gaskets. If you are lucky it will just be the gasket, if not, it will be the head or cylinder face. these can be welded if its in a thick point & ground flush. If not, then you will need a replacement !

Hope that helps.

Chris W.

 

Already ran a compression test all four were within twenty percent of eachother. Also there was a blown head gasket that the guy before me replaced and did everything by the book. I have been changing the oil pretty regularly to clean up the anti freeze he left in there, I made a mistake of fillin the radiator full and the reserve full. Could that be causing a issue? Also I took the thermostat out of the housing and just hot wired the fan to run all the time, and it seems to be leaking from the thermostat housing now. I have re torqued down the heads to specifications with a torque wrench. I have been noticing the oil getting better cleaner but like I said still white smoke when it warms up and revs. Now with that all said is it even possible for the radiator to leak into the engine but not have a bad head gasket? I am not trying to sound rude in any way please don't take it like that I am just asking for help in learning my bike. Thank you all for your replies. And again any ideas are greatly appreciated.

 

water getting into the crankcase without a bad headgasket IS possible, faulty seals on the pump will do it. been there, done that. not on a VF though.

are you sure that what smoke you see isnt just condensation that accumulated n the pipes over time? if its sat for awhile, this happens, and requires running to actually burn off. just went throuh it on a katana 600 in my shop yesterday, firing on 2 of 4 cylinders, ran like garbage til I did that.

 

Hey Korey, you're not rude in any way, just trying to fix your problem.

Compression test only tests the 2nd stroke peak pressure, what I described is a leak down test. That's the reason for having all four plugs out, so there is NO pressure in any other cylinder! So pick a cylinder, turn it manually up to TDC on the compression stroke & then stop there & either counting or using a stop watch check the peak pressure & how long it takes to say halve.

Do this to each cylinder in turn. The peak will be less than when turned over on the starter, but all four should be roughly the same & the one that loses pressure fastest is probably the leaking one ! That's why you should have the radiator cap off, so you will also see any movement in the coolant from escaping pressure.

If they are all the same, then you might have a crack in the head leaking into the inlet tract, this is the only other way I can think of that would get water in the combustion chamber. The VF500 doesn't have heated carbs does it ? That could be another method. Either way you should be losing coolant from the system.

Chris W.

 

Thank you all for your replies. I will reply when I have had a chance to do all the tests. I am in the middle of a move to another state so it may be a couple weeks. Again thank you all and I will get back to you all.