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Discussion Starter · #1 ·
Here is a little bit of the back story to the issues we are trying to fix. I talked my buddy into getting a Honda VTX 1300 and he found one that had been sitting for 5 years and only had 6,000 miles on it. Well the dummy rode it home 50 miles after his purchase before doing any type of tune up. The ride home was fine but after it sat for two days he went out to start it and after a few minutes it started smoking out the exhaust really bad. It is a white smoke.

I had him trailer it to my home and I ran a compression test to the service manual and all looked good. I then removed his Air Cleaner and Gas began to poor out of it. I got it removed and the carburetor. The float was ate up by the gas so we replaced the float, float valve, and float pin. The Carb was cleaned and all other components looked great. I checked his oil and it smelled like gas so I removed both drain plugs and the filter and gas poured out. The gas had an oil feel to it. Now if I would have checked that before the compression test I would have immediately thought bad piston rings. So I flushed his system with some oil and filled her back up. Put the rebuilt carb on and fired her up. For the first 3 minutes we thought the problem was fixed and then the smoke came pouring out again. Also, the Petcock allows gas to drip out in the "ON" and Reserve" position. It is my understanding that with a vacuum Petcock this should not be happening either. We have one on order. Could this be causing to much gas to be getting into the engine creating this smoke?

We are at a loss. We have now dove into the coolant system. Ran a thermostat test and all looked well. I have drained the whole system and will be adding to coolant tomorrow.

What else could be causing this white smoke to be pouring out of the exhaust?

Also, I am sure I need to adjust the A/F screw but want to get some other opinions first. The bike idles fine but if I blimp the throttle she bogs down and then returns back to a good idle. When I rebuilt my carb I did not run into this issue.

Please help!!
 

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Discussion Starter · #2 ·
I want to add that at one point in the bikes life the exhaust got so hot it started to melt the side cover.
 

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It should be very easy to tell (by smelling the white smoke) whether it is fuel or coolant. Also, when an engine is severely overfueling (running way rich) the smoke will tend to be black if it is firing. If it is not firing, and just sucking fuel/air from the carb, compressing it, and expelling it, then it may me whitish.
 

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Discussion Starter · #6 ·
It should be very easy to tell (by smelling the white smoke) whether it is fuel or coolant. Also, when an engine is severely overfueling (running way rich) the smoke will tend to be black if it is firing. If it is not firing, and just sucking fuel/air from the carb, compressing it, and expelling it, then it may me whitish.
The smoke is white. Added new spark plugs and ran it for a minute and pulled them out and they are slightly discolored. It almost smells a little like rubber but not to much. I have never smelled burnt coolant so it could be that.
 

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Discussion Starter · #7 ·
Some how coolant/water is getting into the chamber. The guru's ill be long to help determine how its getting in there.
This is my thoughts as well. I ran a compression test and it is good. The compression test should show a leaking head gasket. I have not ran a leak test yet because I do not have the gauges for it.
 

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I don't know. I have been working on engines for a long time (40+ yrs.) and to get a steady stream of smoke from a failed/worn valve stem seal would be very rare. The clearance betwen the valve stem and valve guide is less than the diameter of a hair. Typically valve stem seal failures manifest themselves by producing a bit of blue (lube oil in the combustion chamber produces bluish gray smoke) smoke on initial start up. This because the oil seeps into the chamber as the engine sits. Then, when it is fired, it burns and you see the smoke. It does migrate into the chamber at a rate to produce smoke with the engine running. Hell, valve stem seals were not even used until the late '50s. If you have seen the exhaust from an older two-stroke engine than you know what oil smoke looks like. Now, if something caused an excessive amount of clearance (wear) between the stem and the guide, that's another story but, that too would be unusual without TONS of miles on the engine. You did'nt somehow get some diesel fuel in the tank did you? Barring that, I think I would pressure test the cooling system. Have you tried running the engine off of an external fuel tank?
 

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Discussion Starter · #10 ·
No diesel fuel. I have flushed the tank, fuel lines, and Carb. Compression Test came back great. I guess I need to pressure test the cooling system. With only 6k miles on the bike I would hope the valves are good. When I get home today I am going to refill the coolant and burp it and see what happens. Could a air bubble in the system cause constant smoke?
 

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Discussion Starter · #11 ·
I don't know. I have been working on engines for a long time (40+ yrs.) and to get a steady stream of smoke from a failed/worn valve stem seal would be very rare. The clearance betwen the valve stem and valve guide is less than the diameter of a hair. Typically valve stem seal failures manifest themselves by producing a bit of blue (lube oil in the combustion chamber produces bluish gray smoke) smoke on initial start up. This because the oil seeps into the chamber as the engine sits. Then, when it is fired, it burns and you see the smoke. It does migrate into the chamber at a rate to produce smoke with the engine running. Hell, valve stem seals were not even used until the late '50s. If you have seen the exhaust from an older two-stroke engine than you know what oil smoke looks like. Now, if something caused an excessive amount of clearance (wear) between the stem and the guide, that's another story but, that too would be unusual without TONS of miles on the engine. You did'nt somehow get some diesel fuel in the tank did you? Barring that, I think I would pressure test the cooling system. Have you tried running the engine off of an external fuel tank?
This info comes from that other site so take it with a grain of salt, it did pass my snicker test. http://www.vtxcafe.com/showthread.php/81232-White-Smoke-may-not-always-mean-the-head-gasket


I will take a video when I get home and see if I can post it on here for you all to see.
 

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1. It should start a whole HECK of a lot easier than it did!
2. It should run better than it does too and not stall
3. It is almost like the choke is on, did he ride it home with the choke on?
 

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Discussion Starter · #15 ·
1. It should start a whole HECK of a lot easier than it did!
2. It should run better than it does too and not stall
3. It is almost like the choke is on, did he ride it home with the choke on?
That was after sitting for 5 years and rode 50 miles to his house from the place of purchase. I want to slap the fking guy lol.

After he rode it home (with no smoke) it sat for two days and this was the start up after it had sat.

He rode it home with 5 year old gas, oil, and coolant.

Now I know the choke is not on because I rebuilt the carb and it's still doing this once the bike warms up.
 

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I think I'd try a double dose of Marvel Mystery Oil and some Seafoam in a full tank of gas and go run it for several miles, watch for idiot lights and see what happens. If it's running okay and no lights, ( temp, oil) what's the worse that can happen. It almost sounds like some varnish on a valve or in the rings and the mystery oil may help clear it up. Just my thoughts and what I would try.
 

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WOW!! Does look more like Oil burning to me..
Doesnt dissipate like Water vapor and has some blue tint to it in the video (or looked like it to me Anyway)...

After sitting for 5 yrs most likely Rings clogged/rusted up or rust on cylinder walls.
IMO.....

I am sure someone here has some solutions for those possible issues..






.
 

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It didn't smell like gas. Kinda smelt like a light rubber burn or something. I have never smelt coolant burning.
It smells like steam there abouts. It doesn't look like coolant smoke like oters have said. I think ur burning oil. Look at your crank case breather hose they get pinched they supposed to go to the air box but if it's stopped up it may create high pressure that may damage the rings just enough to cause oil leak by.
 
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