Exhaust Blackening

[Canuck]

Hey all

My GZ is coming up on is 50,000 KMS, springs coming and I've got time off from work..So i thought i would get a list of things to tackle before i go for my 3rd trip from Vancouver Island BC to Prince George BC.

One things Ive noticed..

Even after a cleaning at the far end of the exhaust where the small outlet hole is, it has black soot staining from 10 O clock to 2 o clock where its obviously emitting black smoke.

I ride with a 16 tooth, Needle Shim Mod. My spark plugs are changed within 2 months Oil as well . I'm noticing the bike is needing a top up of Oil more often than before.

When i get on the bike to go ride i put the choke lever down by half....when the engine gets "angry" or rises i lower it down to 1/4 within 1 minute.. ride away with 1/8th as the temps are between 0 and 10 degrees Celsius (chilly)for 1-2 mins . the odd time i may forget to take the choke off from 1/4 for up to 4 or 5 mins.

Can leaving the choke on cause the exhaust to emit more smoke and eat up some oil more than if i had not drove away and drove with the choke on?


or since im coming up on 50,000 kms the bike internal components are starting to wear and allow more oil to slip into the mix?

maybe my oil is close to 5000kms...


any thoughts ?

[music man]

Yes the choke would make it emit more smoke if you ride with it on, no the choke will not make it burn more oil. And if you did the Needle shim Mod, it is very possible that your bike is running just a tad rich.

What did the spark plug look like last time you changed it, and also when is the last time you changed your air filter.

And yes it is possible that at 50,000 kms you are starting to use a little bit of oil, i just checked and that is roughly 31,000 miles, so that is quite a bit of mileage on a 250, not saying it is ready for the junkyard, just that you have gotten quite a bit of mileage on it.

I am not sure we have anyone else on here that has that kind of miles on there GZ, so as far as a member of this board I would say you are in uncharted territory as far as the life expectancy of your engine goes.

[Easy Rider]

Originally Posted by Canuck

Can leaving the choke on cause the exhaust to emit more smoke

and eat up some oil more

or since im coming up on 50,000 kms the bike internal components are starting to wear and allow more oil to slip into the mix?

Yes and no and yes.......in that order.

Any GZ with over 1,000 miles probably has some traces of carbon at the end of the muffler; I know mine did with about 4K miles. It doesn't necessarily mean "smoke" but some carbon "condenses" at the point where it cools off rapidly.

In your case, however, it probably DOES mean a tiny bit of real smoke, as your rings and valve stem seals are now worn enough to allow a little oil into the chamber where it is burned. That's pretty much normal engine wear and not much you can do about it. Also nothing to worry about really unless and until your performance is affected or the oil consumption becomes excessive. Might need to change the plug a little more often as things progress......and keep a closer eye on the oil level.

Going one step up in oil viscosity during the hot summer months might help a little but don't get your hopes up too much.

[blaine]

If you did not go with aftermarket air filter its probaily running a little rich,a check of the plug will tell you if your running rich.A little rich is better than too lean as long as its not fouling plug.

[Canuck]

As far as the spark plug last time i checked...dark Grey not sooty black

air filter... has some evidence of oil on 25 percent where it is exposed to the carb port not soaked though

I bought the bike at 17000 kms and am now at 50,000 I ride all year round and do regular maintenance checks including the valve adjustment which is set in the middle of the suggested settings

I have Bardahl engine oil at the recommended grade 10 w 40 i believe...not synthetic however before this oil change i had Motul full Synthetic 10 w 40

I get 375 kms per fill up on avg so mileage is good

Really Music Man?? i would of thought someone or many would have had more than that ... thats great!

still love ridin the blue dragon!

[Canuck]

also i have been through 3-4 cans of Seafoam...both in the gas and in the engine itself

[alantf]

Originally Posted by Canuck

also i have been through 3-4 cans of Seafoam...both in the gas and in the engine itself

"and in the engine itself" ?????????????????????????? :??:

Do you mean that you mixed it with the oil?

[Canuck]

yes i did! hahah

no adverse effects at least... and i havent used the stuff in 2 oil changes (left it out of the synthetic oil change)

it does say on the can you can put it in with the oil... not alot for the GZ but alittle...might hurt? might not ?

I tried it and noithing spectacular occured so ... i stopped using it ... and now for a carb cleaning i used the Gunk Carb spray when its time to pull the carb off

[music man]

Originally Posted by Canuck

yes i did! hahah

no adverse effects at least... and i havent used the stuff in 2 oil changes (left it out of the synthetic oil change)

it does say on the can you can put it in with the oil... not alot for the GZ but alittle...might hurt? might not ?

I tried it and noithing spectacular occured so ... i stopped using it ... and now for a carb cleaning i used the Gunk Carb spray when its time to pull the carb off

It says you can use it in oil, but they didn't have an engine with a wet clutch system in mind when they said that. So yes it is safe to put it in engine oil, but not safe for transmission/wet clutch use.

[Easy Rider]

Originally Posted by music man

So yes it is safe to put it in engine oil, but not safe for transmission/wet clutch use.

A LOT of riders seem to do it though with no ill effects.....but no demonstrated gain either.

I certainly wouldn't take the chance......and who knows what it might be doing to your valve guide seals.....which often give out before the rings do.