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Gas Leak/ Smoke

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Hey guys so my 79 has a real tiny gas leak. Pretty sure it's from one of the carbs, but not 100%. Any tips as to where it is and how to fix it? Also, recently, my bike has had some smoke coming from around where the exhaust meets the engine. Does that happen when there isn't enough lubrication in the gasoline? Thanks
 
' Does that happen when there isn't enough lubrication in the gasoline?'

What lubrication and how did you get there?.................an odd question.

As to the leak, well, your eyes are there and ours aren't. You gotta LOOK, Bucko..................and THINK. How can you be told how to fix it when you don't even know where it is???
 
The lubrication is Marvel Mystery Oil. The red stuff. I know that since the gas nowadays is unleaded it needs lubrication to run through the motor, and I just thought that maybe the smoke was coming from the gas being dry in the motor.
 
Uh, the oil really does nothing but stack your plugs up faster. The worst thing unleaded fuel does is put the exhaust valves and seats through more hell than before and nothing in the oil touches that whatsoever. There's virtually nothing that replaces that lead my friend. Honda used interim heat treats on their bike valves too, they were intended for low lead and low even as low in content as it was was 500% better than totally unleaded. I ran several cars through the era of 100% dropping of all lead and the slight difference that showed up in engines with non-induction hardened exhaust seats multiplied by a fact of like 10X when that last bit of lead disappeared. Honda nitrides super cheap low grade steels for their exhaust valves and why you can't grind them doing so makes them wear inside of 5K miles to be garbage, the valves are so soft they are junk once cut. If you even lap them in too far you can remove that nitride and valve then history in pretty short order. Why the DOHC is so susceptible to valve burning issues once the clearances get too close even if you think they are not. Why opening the clearance from .003" to .005" can make them last super long distances more than the stock OEM setting ever did. Read my other posts about why that .003" setting you think you got is not real world at all and very deceiving.

I used to sell various engine treatments and concoctions in the parts trade, I can tell you that most if not all of those may well have some slight specialized use but not normally, they actually fix the vehicle owner/operators far more than they fix the vehicles themselves. I smoked plenty of people about how well those chemicals worked and not proud of that, but now I go the other way. I myself have never used anything other than decent oil and fuel in any car or bike I've ever had over some 50+ years now, it's simply too easy to fix them to run right rather than grab for the 'crutch' of chemicals, they are for people that do not know how to fix things in my view.

Absolutely no insult intended at all to anyone but I like to get that out there. Save that cash............of course one person's view only.

Your smoke issue most likely only petro chem seeping out of pipe around gasket to then burn. That first foot of pipe gets up to like 800+ degrees there if singlewall. Some of your oil will have settled out as carbon in exhaust port, may even be slightly wet. You do know that oil in the fuel of a 4 stroke leads to detonation right?
 
The Marvel Mystery Oil isn't like motor oil I don't think. So the smoke coming from it is from the valves being too close? Or the petro chem burning? If it's the burning, is that safe or should I look into the leak?
 
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