Timing and Smoke

[jmcgill89]

In general, would a GT550 smoke more if the timing was too advanced or too retarded? I'm getting a dial indicator this weekend to properly try to set the timing, but I may want to ride it a bit before then.

Similarly, would poor carburetor adjustment cause a bit too much smoke? I'm really laying down a smokescreen when I wind out the trottle. When it's warm at idle, it's not all that bad.

Thanks,

Joe

[Coyote]

Sometimes just a poor choice of oil can cause excess smoke. What are you burning? If it's cheapo stuff, treat yourself (and your bike) to a quart of Suzuki CCI or a synthetic like Silcolene. I might be wrong, but I don't think timing or fuel adjustments will affect it much, unless the smoke is black -- indicating an over rich condition.

[jmcgill89]

I'm running Yamalube 2s in there right now...I'll try to locate something else.

I can use the synthetic injector oil they sell at the local motorcycle shop?

The smoke is white/blue, and it smells like my Lawn Boy or Evinrude or Chainsaw.

[tz375]

Could it be that it doesn't get ridden enough to get teh pipes really hot and burn off all teh old oil? It takes a while to come clean as a rule. My RZ smokes really badly when I first start it and accelerate, but aftyer a couple of hard acceleration runs, it is more or less clean with zero smoke and that's with Yamalube S.

It could also be pump adjustment.

[jmcgill89]

The baffles are REALLY oily...I need to take them out and clean them off.

I'm hoping that's all the problems really are.

[H2RICK]

Joe, modern oils (especially mineral types such as Yamalube and CCI) are intended to run at 40:1 instead of the 20:1 setting for the pump that was used back in the day with the oils that were available then. You can cut the pump back from the stock setting quite a bit to reduce the smoke. You can do this yourself by turning the adjuster bolt for the pump cable back IN towards the pump itself a half turn at a time and then going for a 30 minute ride and then checking the plugs when you get back. Keep doing this until you get plugs that are the correct colour and you should notice a substantial reduction in your visible smoke. I would recommend starting this procedure with a fresh set of plugs. NGK B8's are a little too cold for most uses except long haul highway use in warm/hot climates. I use B7's in my 550 exclusively and she's been happy even when used for day trips with a lot of highway travel.

Another thing to watch out for is a sticky lever on the pump that won't return to the idle position correctly. There's a service bulletin covering the "sticky lever" problem.....but for some reason I can't seem to see it on http://www.3cyl.com" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;. I have a paper copy I can scan if you need it. Let me know.

Lastly, you may have some plugged SRIS valves and/or hoses. This, combined with a too-rich pump setting, will certainly give the symptoms that you describe.

[jmcgill89]

I already have cut back the pump a bit.

Last time I pulled the plugs, they were a dark tan in color on the electrodes....not too bad.

I will have to look into the sticky return problem and the SRIS valves.

Thanks a bunch!

[jmcgill89]

I found the bulletin about the check valve strainer for the SRIS. I'm still looking for the one about the sticky lever.

Anyone have any specific way to make sure the hoses are clean on the SRIS?

Oh, and It's using B7 plugs right now.

[tz375]

AFAIK, Sticky Lever Syndrome (SLS) is a bit of an urban legend. Not to say that it isn't possible, but it's the way the pump is designed. When the motor stops, if the pump rotor is in the upper position, the lever arm cannot return to the fixed position. It hangs up and feels "sticky" because you are actually damaging the pump top try to force it closed. Rotate the motor a few times to get it off the cam face and it will return naturally.

To clean out the crankcase and SRIS lines, disconnect one end and apply a MITYVAC to suck out any oil.

[jmcgill89]

Well, the check valves in the SRIS aren't shot....I can draw air through them using a vacuum pump, but I can't blow air back through them.

I played with the timing yesterday, and got it as close to the "factory" marks as I could....doing this, I have the timing plate rotated almost all the way to one side. It started very easily and idled well at 1500 even when cold, still smoking up a storm until I warmed it up.

One thing I have noticed is that when I hit heavy acceleration at mid range rpms, the bike wants to "four cycle" (I can't think of a better term for it). Is that a carb adjustment, or timing, or what?

Thanks!

[Suzsmokeyallan]

It sounds like you've covered almost everything right so far, have you removed the oily baffles and stripped off the packing? I'd do that if you haven't already, then wash them up and repack.
Are the float levels correct on the carbs and the needle valves and seats good, also check the choke plunger rubbers and their springs for correct tension and full seating, if they are not right you will get a partial 'choke on' condition at times. The four cycling you speak of is usually an overly rich condition caused by a high influx of mixture, BUT carboned up engines will do it too if they have not been run hard for a while.
What about the air filter element is it clean and up to scratch?
The bike may just need the pump dialing back a slight bit more and then taking for a good few hard blasts to clear out all the old oil residue and wet carbon thats inside of it.
If you dont want to be caught speeding, find a reasonably quiet road of about 100miles out where you can ride at a constant 70 mph, then at intervals open it up, then go back to cruising at 70mph, repeat as needed.
The 200 miles you travel doing this should clear things up significantly and you will more than likely have to repack the baffles after this trip as they will probably be soaked again.
As you 'burn off' the residue it gets thrown backwards to the end of the pipes, and as the new clean portions are exposed they heat up faster, and so its a process of slowly peeling back a layer of oily grunge/wet carbon from the exhaust ports to the end of the pipes.
It sounds like this engines of yours is pretty much clogged up from a lot of slow riding and residual oil, it took me about 4000 miles of high speed riding and hard blasting to get my 76 Buffalo cleared of all the old carbon and oily residue the PO put in it.

[jmcgill89]

How do you clean and repack the baffles? They're pretty filthy.

I just started it up, and there was visibly less smoke after I set the carbs to .75 turns out on the pilot.

I'm going to take it on a good drive today.

[Suzsmokeyallan]

Pull the baffles out and wash in some solvent to remove the oil first, if they are carboned up, place them in the BBQ after drying off the solvent and bake them.
Once the carbon is dried up and flakes off easily, let them cool off, then make a rod out of a coat hanger or such and beat one end flat like a screw driver tip. Use the rod to get into the flutes recesses to remove the scale if theres plenty stuck in there.
As you clean them out, tap the baffle to shake out the excess as you go, packing can be obtained from your Local Bike Store and you can use the one for off road bikes.

[H2RICK]

AFAIK, Sticky Lever Syndrome (SLS) is a bit of an urban legend. Not to say that it isn't possible,

Suzuki thought it enough of a problem to issue a service bulletin, at least in Canada, as early as 1971. I might have thought like you but the bulletin mentions that a new type of low-leakage oring on the lever shaft could be the culprit.
I occasionally ran into this situation back in the day, so I WAS aware of the potential problem. On affected pumps the lever WILL stick even with the engine running so it has nothing to do with the plunger cam position.
My 550 exhibited the problem within days of me getting it back on the road after my purchase. This was in 1990 and the clock read 660 miles when I bought the bike. I had pulled the SRIS valves when I bought the bike as part of my normal checkover of any used bike. The crank chambers had more than normal amounts unburned gas/oil so I can only assume that the sticky lever problem might have lead to the bike being laid up in the first place. The goofs that attempted to "repair" the bike before I got it had no clue as to why the bike was fouling plugs like crazy and had gone off in a totally wrong direction with their "repair" attempts. Thankfully I got there in time to save Indy from further "repair" attempts.
I installed a light spring on the cable with just enough tension to return the lever under all conditions. It took over 3,000 miles before the oring was "worn in" enough to allow me to remove the spring. Everything has been copacetic since then and there's now ~7,000 miles on the clock.

[jmcgill89]

Ok, well, I took it out for about a 14 mile ride today, and it was fast, and didn't seem to be smoking all that much at speed....it was still "four cycling" around the 3000 RPM range.

I decided to take the plugs out when I got home and shoot a video of it idling in the garage.

Here are the plugs....first the left one, then the right one (the center was EXACTLY like the right one). The left one wasn't wet at all, the right was wet, not dripping wet, but wet.

I don't know if this site does videos, but I'll try to put it on youtube or something.

When I got home, the center carb was overflowing badly onto the garage floor, so I decided the GT550 was done for the winter, and I'm going to push it into the basement for a carb overhaul and to get the timing set with the dial indicator.

What causes that carb overflow like that?