Smoke question probably already asked ad nauseum

[polishbeer]

Hey folks,

I have a 1974 T500 I got running. Took it to Deals Gap no problems in 500 miles.

Guy riding behind me said I'm smoking more from the left pipe than the right side. So thinking maybe it was an air bubble, I pulled the oil lines off the right side, connected them directly to the oil tank and sucked the oil through orally then reconnected them.

Smokes fine from both sides for a while then again, more from the left. Sometimes no smoke at all visible from the right side.

I'm thinking this is a center seal problem but wanted to ask the brain trust first. It runs really strong, goes like a slingshot above 4k. I like this bike but don't want to do damage.

Here's a pic. I did the repaint. I'm not crazy about the way it turned out but I'm not keeping this bike. Bought it to flip. I have too many bikes.

http://tinyurl.com/nhfbaek" onclick="window.open(this.href);return false;

[pearljam724]

Read and compare plugs to see if one is noticeably leaner than others. Clean and balance carbs. No change, do leak down test. Check oil feed and timing. One of those issues is causing more or less smoke. Not trying to startle you. But, usually points to crank seals. Other things can cause more or less smoke from one pipe. You have to investigate those 4 or 5 causes. Reading and comparing the plugs easily tells you something right off the bat. You have to read them at different rpms and kill ignition before that reading will change due to fluctuation of rpms, air and fuel. Readings at idle, mid and high rpm for example. Check jet sizes pertaining to your stock or aftermarket exhaust also.

[GT750Battleship]

Hi your right Adnauseum it's been discussed over & over on "here" & elsewhere, & I still haven't heard of a bike seizing or stopping because of it stop worrying everybody My GT750A has been "swapping" smoke from one pipe to the others for 14 years/70,000kms
Cheers,
Roger

[Eddie]

my 74, gt750 has been smoking more from the left cylinder than the others ever since I bought it, I have tried everything (carbs,timing,etc..) and it will stop for a little while and go straight back, mine smokes more at start up then when warm it goes away , and sometimes it doesn't go away, my advise is check plugs to make sure theres no lean plug and after you do everything that was mentioned from pearljam id just ride it! if it runs good ride it until it actually breaks down , that's what im doing

[GT750Battleship]

Cheers Eddie,good man....if the bike is going well, leave well enough alone
Regards,
Roger

[ConnerVT]

One of the reasons that 2-strokes were pushed aside by 4-strokes, and haven't truly returned to the street market in decades. You can't rely on 40 year old technology (now using 40 year old parts) to precisely supply the exact amount of oil needed in all situations to prevent smoking (or at least, do it uniformly).

Outside of all the catastrophic reasons everyone worries about, a slightly maladjusted oil pump, a slight leak of an oil line check valve, differences in carb setup and/or ignition tuning, all can supply a bit more smoke from one cylinder compared to another. Put around town a bit, then get on the throttle. One cylinder runs a bit warmer than the other? the cold side has a little extra oil to burn, waiting in the crankcase.

Unless it is a *LOT* of smoke, and you have reason to suspect a major issue, ride and enjoy. Maybe you also need to get on to the throttle a bit more often.

[Desert_75]

Which oil are you running? I run the Motul 710 and after warm-up there is virtually no smoke at all