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Smokey NSR


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Steve C
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Smokey NSR

Sun Jul 08, 2007 7:11 pm » Post: #1 » Download Post

My mc18 has always been very smokey during start up and well all the time (at idle). Andy I was wondering if you ever got around to replacing the crank seals on your NSR and did it make a diffrence in the smoke out put. I don't really mind leaving a light in a big cloud of smoke. I have never had any gas in the gear box and have never noticed the gearbox oil level drop. I had the jetting set and have the smallest pilot jet I could find installed.
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Andy
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Sun Jul 08, 2007 7:32 pm » Post: #2 » Download Post

I have a rebuilt crank in my 21 now, but we went right through the motor at the same time, so I can't say what effect just the seals would have made.

What's the motor like once warmed up to normal operating temperature? I've seen a couple of 18's that seem to pump the smoke out when cold, as if the pump over-oils slightly until the solenoid switches. I take it the pump is set correctly?

Some oils can smoke more than others too. I find the Rockoil we use seems to smoke a little less than some of the others.
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Steve C
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Sun Jul 08, 2007 7:49 pm » Post: #3 » Download Post

When it warms up it gets alittle better but if you sit at a light or stop and go it gets smokey again. Pump is not a problem as it is premix I run 32-1 . I have tried a couple of diffrent oils Motul low smoke cuts down on the smoke some. I guess it's just the way it is I don't ride it very often. So maybe the gas and oil settle in the bottom of motor and it takes a while for it to burn away.
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fontyyy

 
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Sun Jul 08, 2007 9:48 pm » Post: #4 » Download Post

In my experience pre-mix smokes like crazy pretty much all the time unless it's being hammered.

All the bikes at the races chuck the stuff out like it's going out of fashion (as well it is).
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Dave Ett
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Sun Jul 08, 2007 9:54 pm » Post: #5 » Download Post

Valve stem seals gone I think... Wink
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Sun Jul 08, 2007 11:47 pm » Post: #6 » Download Post

I use Motul 710 and it smokes like crazy on start up.... Once warm it doesn't smoke at all (oil injected)....
Now on my RMX though, I use syn. oil at 50:1 and it smokes a lot all the time... So maybe it is a premix thing ?????
If it's not fouling plugs it can't be to bad, right?
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Matt@TYGA
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Mon Jul 09, 2007 1:29 am » Post: #7 » Download Post

It's a pre-mix thing.

The pump delivers something silly like 100:1 at idle, so it's no surprise that if it's coming in at 30:1 ish then it'll probably smoke.

If I'm sitting at the lights idling it'll start to smoke, but once I'm away and have hooked a couple of cogs it'll clear up.

Take a look at the GP bikes. During the race there's not a wisp of smoke as they're so finely set up, but on the slow down lap quite a few will be puffing smoke.
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j911brick

 
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Mon Jul 09, 2007 2:11 pm » Post: #8 » Download Post

Funny you should mention this. My -21 only smokes from the top cylinder at low rpm; then as you rev it it will smoke from both cylinders; then it doesn't smoke from either cylinder. I figured the rings might just be seating in. I still have the injection.
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maxim
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Mon Jul 09, 2007 11:21 pm » Post: #9 » Download Post

Most 21 and 28's do that don't worry.
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j911brick

 
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Mon Jul 09, 2007 11:25 pm » Post: #10 » Download Post

Thanks, that helps!
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Tue Jul 10, 2007 11:40 am » Post: #11 » Download Post

Hi,

I don't know how good is your bike. When I bought my NSR it had the same problem. I have done everything possible, and tried all Oils available.

The problem was in the exhaust pipe. Finally I have dismantled it, and one will not believe what was inside. It stopped smoking and it start to speed up better as well.

May be you should try this. However, note, that my nsr was in the garage for more then three years when I bough it.

Try, may be it will help.
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Tue Jul 10, 2007 1:12 pm » Post: #12 » Download Post

BAD BOY wrote:Hi,

I don't know how good is your bike. When I bought my NSR it had the same problem. I have done everything possible, and tried all Oils available.

The problem was in the exhaust pipe. Finally I have dismantled it, and one will not believe what was inside. It stopped smoking and it start to speed up better as well.

May be you should try this. However, note, that my nsr was in the garage for more then three years when I bough it.

Try, may be it will help.

What was in the pipe ?
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