[The New Owner]

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Hi there! Maybe I already mentioned sometime that I have a blue smoke on startup from both the exhaustswhich disappears after a few miles (or minutes) of riding. However, the situation had changed. Today when I started the bike, like usual a large amount of blue smoke was pouring out the exhausts. I let it idle for about 20 minutes but I still had the smoke. I went for a ride and after few miles the smoke disappeared, but only temporary. When Ilet the bike idle againon its side stand there was no smoke for a first few minutes, but then I opened the throttle a little bit so the RPM increased to about 3000. After few seconds of this "fast" idling the bluish smoke suddenly appeared again, first from the right hand exhaust, then from the other one as well. The magnitude of smoke was variable, in one moment there was a lot of smoke, then less (or nothing), then again a lot, while the engine was "fast" idling on about 3000 RPM. Similar situation on both the exausts. I removed the crankcase breather hose before riding, with the engine still cold and was checking for any smoke from there since the beginning. While the engine was cold (a lot of blue smoke from the exhausts) there was abslolutely no smoke from the breather, only the air. When it warmed up (after riding), when point a bright flashlight in the breather, there wassome barely visible vapour, I think white coloured, but there was just a little bit of it, almost nothing. Normal oil vapours? Also checked up the oil filler hole, no smoke from there. Now here is the compression (measured with the engine stone cold) : #1=148 #2=152 #3=143 #4=145 Lbf psi

So, no cylinder was under 142 (the manual service limit)and the biggest difference was 9 (service limit 15 by the manual). I also noticed that the spark plugs #2 and #3 looked better than the others. They were brown coloured on top while 1 and 4 were black. So, that's it. I hope that the piston rings arenot the causeas the compression is satisfactorily and there is no smoke from the breather, but am I maybe wrong? So, I amthinking about two possible options: 1) bad valve stem seals and/or guides or 2) too thin oil (caused by the fuel coming in it as the carb floats are bad, I must fix that as well) which can easily pass the valve seals and come into cylinders. So, I must rebuild the carbs and change the oilanyway, but is it a good idea to change the valve stem seals as well?If so, then to do it without removing the heads orto remove the heads and then check the valves as well? Any other possibility, like bad piston rings or something else?

Sorry about that long text and thanks a lot! Alex

 

[DaveO430]

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Fix the carbs, change the oil and ride it. Your rings and valves are good according to your compression test.

 

[dan filipi]

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I had a engine with a bad oil ring acted much the same way with the smoke, especially bad when cold started even on the center stand.
Compression was 155-160.

AFAIK, The condition of the compression rings and cylinder determine the compression pressure, condition of the oil ring and cylinder determine the oil control/wiping.

I agree, fix the carbs and change the oil then see how it does.

 

[William_86]

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try using seafoam to remove build up carbon from cylinders and rings, it may get them to seal better.

 

[exavid]

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Your compression looks pretty typical, it the engine were warmed up you'd see another 10psi or so. A warm engine will turn over faster on the starter so the compression is quite a bit better looking. Your starter and battery have a large effect on the compression reading too, the most important figure is the difference between cylinders. Checking the valve clearances before doing a compression check is also a good idea, a slightly tight valve can effect the result.

Your differences in spark plug colors sound like possible carb problems, maybe the #1 and #4 carb floats are leaking or not properly set. It's probably not an ignition problem since #1 & #2 are fired by one coil and #3 & #4 are fired by the other coil.

Oil dilution caused by fuel getting into the crankcase can definitely effect both the compression reading and cause smoking. It's important to shut off the fuel petcock each time you shut off the engine. Some people don't but it's just asking for trouble if you don't. Drain your oil and see if it's unusually thin and if there's more of it that there should be.

 

[The New Owner]

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I always shut off the petcock after riding. However, I had the oil level raising and thought that it was the coolant coming in it, however when I drained the oil out there were no signs of coolant but it smelled like gasoline and was thiner than it should be. On this forum I was adviced to check the plenum's bottom after riding, I did it and saw a lot of petrol down there, soif I understood wellthat would mean a bad float valveswhich let too much fuel in the cylinders and then unburnt fuel goes into the crankase, right? Once while the bike was idling on the side stand I also had a sudden white, gasoline vapourfrom the left hand exhaust, which was there only for a few seconds and then disappeared. Also confirms a bad float valve, right? So for now I will just rebuild the carbs and change the oil, without messing with the valve seals. I'll also try to find that sea foam, but I am not sure if it could be find over here. To use some other engine cleaner?

Thanks for the great help! Alex

 

[cycleman]

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From your symptoms the engine is flooding itself. Carb rebuild & oil change should help.

In the meantime, Sea Foaming the carbs/fuel system would certainly help a lot. Sea Foam is basically an oily solvent so if you can find something similar that is based on a petroleum product it might help. You have to watch that it won't hurt rubber components.

Check around with some garages in your area, they might no of something. Whatever you do don't take the carbs off and soak them in carb cleaner. Many small pieces that don't like that stuff.

 

[AZgl1800]

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I do not think Sea Foam is sold outside the USA.


It is a Naphtha based product and Forum member 'Q' tells how to make your own if you wish in this thread:
http://www.goldwingfacts.com/forums/forum4/59421.html

 

[exavid]

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I don't think any carburetor cleaner is going to help in your case New Owner, a float valve that leaks is either damaged, misadjusted or the rubber has hardened up on the tip of the needle. It would be best if you corrected that problem before running the engine much more because the diluted oil will cause bearing damage. It would probably be best if you obtained four new valve sets from Honda, most of the aftermarket float valves don't seem to work well. I bought a set of aftermarket valves and never could get them to adjust properly without leaking. Don't know why but apparently they use a different type of rubber or whatever on the valve tips that takes more pressure to seal.

It could also be your petcock isn't sealing, a kit to rebuild the petcock or just replacing the petcock would be worth doing as well as the carbs.

 

[bikgra]

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You need to replace the Valve stem seals.My 76 GL1000 did the same

 

[The New Owner]

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The home-made sea foam sounds intresting....I think I'll try to make it if I don't manage to buy it. Well, first of all, I must find a way to take the bike 100Km away from here to the certified Honda Motorcycles service, as I may not ride it in this condition, I think it wouldoverflow the crankcase with the gasoline. I want them to rebuild the carbs for me, as I don't haveany experiance with multiple carbs systems, so wouldn't like to mess up anything. After that I will see how the engine works and maybe then change the valve stem seals if needed, as I can do that myself.

Thanks! Alex

 

[Moffat]

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Is your Oil level going down (which probably means you are burning it) Are you sure that the smoke is b lue and not black???

 

[GregForesi]

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+1 on the valve stem seals. My original ones crumbled in my hands when I pulled them. I may have a couple of leaks in my bike but it doesn't burn oil any more.

After flushing the crankcase with Marvel Mystery Oil (once last spring and once this spring) my piston rings seemed to have loosened up as well.