Engine overheating and smoking a lot ?

[poelinca]

It only happens for the first half of the day/ride, the engine is overheating and on some difficult hill climbs it smokes a lot. The smoke has a strange smell to it, gray in color (it's definitely not the pre-mix, i'm sure of that).

Does not loose gear box oil or cooling fluid, at least not noticeable after a few rides (aprox. 7-10 engine ours).

It's getting worse and worse after each ride, this last ride we did the clutch started to squeak and it never did that (i did not change the gear box oil, so it doesn't have anything to do with it i suppose).

The PV will not open if the engine is not hot, it's strange because it used to open any time, now it only opens after 10-15 minutes of riding time (i always warm the engine 5 minutes before a ride). Before that it makes strange noises, like a box of nails or smth. This issue might not be related to the overheating tough.

It all started when once, i forgot to remove the exhaust plug while warming the engine for a ride, so the engine had run with the plug in for 30s/1minute before i realized what happened.

Maybe it's a gasket/seal somewhere that broke while running the engine with the exhaust plug in ? Witch one would it be ? Where do i look for wear and tear ?

p.s. it never happens after the "lunch break", we usually stop half way on a ride to eat and it never has the described symptoms after that

 

[Jakobi]

What makes you think it is overheating?

What makes you think the powervalve isn't opening? Seat of pants, or have you physically confirmed?

It all sounds very odd. I would do the following based off what you've said.

Drop crank case drain plug. Make sure you don't have excessive 2T in the cases.
Replace the plug.
Physically check RHS engine (powervalve actuation/governor/clutch assembly).
Check stator side seal.
Change transmission fluid to fresh oil.

None should set you back too much in time or dollars.

 

[RBrider]

I wonder if the primary side crank seal is going bad?? it could be sucking in a little transmission lube.

Also, pull the PV chamber on the left side of cyl and make sure it's not clogged with unburnt 2 stroke oil.

RB

 

[barossi73]

Im surprised it ran with the exhaust plug in at all!..it really shouldnt
Do you wash bike between every ride?
Or ride deeper water
Maybe your gettin water in the system via airbox?check filter is fitted right with fingertips
Have you thrown away or at least opened up the rubber duckbill drain on your airbox?otherwise everytime you wash you half fill the airbox and will not drain.
Water in the exhaust pipe?
Esp if you use pressure washer.
In light of the fact it ran with exhaust plug in id check your pipe/can joint.could also let water inside pipe when washing
Otherwise suspect small coolant leak.check headbolt torque

 

[poelinca]

What makes you think it is overheating?

What makes you think the powervalve isn't opening? Seat of pants, or have you physically confirmed?

It all sounds very odd. I would do the following based off what you've said.

Drop crank case drain plug. Make sure you don't have excessive 2T in the cases.
Replace the plug.
Physically check RHS engine (powervalve actuation/governor/clutch assembly).
Check stator side seal.
Change transmission fluid to fresh oil.

None should set you back too much in time or dollars.

It revs very bad from the point where the PV should open and clean "on the pipe" sound should be heard. It sounds like a box of nails, and doesn't rev too much beyond that point. Didn't physically check but will do and come back with the result.

The plug was replaced 17-18 engine hours ago, i'll change the oil and see if i find anything bad down there.

I wonder if the primary side crank seal is going bad?? it could be sucking in a little transmission lube.

Also, pull the PV chamber on the left side of cyl and make sure it's not clogged with unburnt 2 stroke oil.

RB

What seal are we talking about ? I don't understand much from the term as i don't have too much experience with engines and terms. If i see it on the parts breakdown i'll understand it's role and will be able to investigate further.
Is it numbers 4 and 9 on this image ? Witch would mean i have to split the cases to change them right ?

I'll take down the right side and left side PV covers, and clean it all up. See if it makes any difference.

Im surprised it ran with the exhaust plug in at all!..it really shouldnt

Do you wash bike between every ride?
Or ride deeper water
Maybe your gettin water in the system via airbox?check filter is fitted right with fingertips
Have you thrown away or at least opened up the rubber duckbill drain on your airbox?otherwise everytime you wash you half fill the airbox and will not drain.
Water in the exhaust pipe?
Esp if you use pressure washer.
In light of the fact it ran with exhaust plug in id check your pipe/can joint.could also let water inside pipe when washing

Otherwise suspect small coolant leak.check head bolt torque

It ran very very bad with the plug in, but it did ran. I started to look immediately and that's when i have found the plug in.

I wash the bike with the power jet maybe once 3 rides and always start it up and get it up to temp after the wash to make sure any water that gets inside will be evacuated. Pipe seals are new, 17-18 engine hours but i'll check them and all the joints.

 

[barossi73]

Water pooling in the airbox wont dry by running the engine after a wash.the rubber drain/plug blocks very easily and water will just sit in there around your airfilter
White/grey smoke usually means water vapor

 

[poelinca]

Water pooling in the airbox wont dry by running the engine after a wash.the rubber drain/plug blocks very easily and water will just sit in there around your airfilter

Oh, the drain there in the air box is not clogged. I check it when i clean and spray the air filter witch is before every ride.

 

[barossi73]

Ok.did you try jakobi's suggestion and drain crankcase?looks like oil drain plug but closer to front of bike.there should be almost nothing drain out but a few drips of slimy oil.

 

[poelinca]

Ok.did you try jakobi's suggestion and drain crankcase?looks like oil drain plug but closer to front of bike.there should be almost nothing drain out but a few drips of slimy oil.

And that is with the oil already drained or not ? Will do it in a few hours when i get back home and report back. Thanks

 

[ramcclure200]

When you shut the motor off is the pipe smoking?
If so she's hot and running lean

 

[poelinca]

When you shut the motor off is the pipe smoking?
If so she's hot and running lean

Yes that did happen when it smoked a lot. But that would mean it should happen all the time, not for the 1'st part of the ride ? I'll take the spark plug out and take a pic of it, that should address this issue better.

p.s. if it's lean shouldn't it start hard/run bad on high altitude ? the bike starts first kick every time, hot or cold from 300 up to 1800 meters, i never had a problem regarding this, never had to fiddle with the carb (so it means it's actually running rich right ?)

 

[Stoby]

oil seal

If your oil seals leaking it'll cause the odd odor and smoke
And i would assume could be causing detonation = possible overheating.
Stoby

 

[ramcclure200]

Yes that did happen when it smoked a lot. But that would mean it should happen all the time, not for the 1'st part of the ride ? I'll take the spark plug out and take a pic of it, that should address this issue better.

p.s. if it's lean shouldn't it start hard/run bad on high altitude ? the bike starts first kick every time, hot or cold from 300 up to 1800 meters, i never had a problem regarding this, never had to fiddle with the carb (so it means it's actually running rich right ?)

Well i'm not a jetting expert by any stretch just had an experience when my bike leaned out and eventually seized and it smoked from the pipe when i shut it off. I'm at sea level so no experience with those kind of altitudes but after reading over your post again the other guys may be on to something with the seals going bad!

 

[barossi73]

Crankcase drain is seperate from transmission oil so doesnt matter if you have dropped trans oil or not.its useful for draining water when bike has drowned or in your case for eliminating coolant/excess oil fouling the fuel mix
Smoking from pipe after engine off can also occur after a prolonged wot run,esp if there was a lot of slow puttering before.the excess oil buildup gets hot enough to smoulder in pipe.could be,but not necessarily a lean symptom.

 

[Jakobi]

And that is with the oil already drained or not ? Will do it in a few hours when i get back home and report back. Thanks

Crankcase drain is seperate from transmission oil so doesnt matter if you have dropped trans oil or not.its useful for draining water when bike has drowned or in your case for eliminating coolant/excess oil fouling the fuel mix
Smoking from pipe after engine off can also occur after a prolonged wot run,esp if there was a lot of slow puttering before.the excess oil buildup gets hot enough to smoulder in pipe.could be,but not necessarily a lean symptom.

Exactly! The crank case drain is just a hole through the bottom of the cases into the crank case. It's very helpful if the bike gets drowned and filled with water. I've had mine flow like a tap before

If all is as it should be you should only have a small pool of 2T oil pooled in the crank cases, and if the engine has been turned over a few times it should be coating your big end and crank more than running out the drain when you remove the plug. If you are getting water into the crank case you'll see the oil has emulsified and gone creamy like.

I also agree with barossi regarding the pipe smouldering. If I transition from a day in the singles to doing some 5th - 6th wide open I can get enough heat into it to burn off the excess oil. I've also run lean enough to have the bikes power curve dropping flat under load and not had any smoke from the pipe. A lean setup can also cause that too.

In relation to the crank case seal on the rhs, it doesn't really explain why the bike would run poorly in the morning and OK in the afternoon. I would replace this seal and o-ring if you dig deep enough to get to clutch and PV governor. Cases do not need to be split, but the RHS engine case/cover does need to be removed and can be done with the bike laid over on its side. If you are losing significant volumes of oil you can measure what comes out vs what goes in with the transmission oil. If it's being burnt off you'll have the rich smokey condition and poor running along with less trans oil coming out when changing it. I always pour the old oil back into a 1L bottle for a quick crude check.

While a bike shouldn't run with the bung plug in, I must say I have done this too. Bike has fired up a-ok but it's immediately noticeable that the exhaust isn't flowing and I'm sure if you tried to keep it running long enough it would flame out/load up. We've used the method to snuff a husky WR300 that had its kill switch disconnected due to it shorting.

Have you changed filter oil recently? or started over oiling the filters? It's hard to tell by reading if you are saying that the engine just won't rev and is running poorly like it's over fuelling/loading up, or if its mechanically not opening the PV. When my PV stuck wide open the engine truly sounded like a bucket of bolts - not just didn't sound right - it sounded fatal.

 

[poelinca]

Drained the crankcase, only a few drips of oil came out. It looks and feels the same as the gear box oil.

As for running lean/hot, here is the spark plug after aprox. 18 hours of usage

LHS PV, it looks like water in there.

 

[poelinca]

Exactly! The crank case drain is just a hole through the bottom of the cases into the crank case. It's very helpful if the bike gets drowned and filled with water. I've had mine flow like a tap before

If all is as it should be you should only have a small pool of 2T oil pooled in the crank cases, and if the engine has been turned over a few times it should be coating your big end and crank more than running out the drain when you remove the plug. If you are getting water into the crank case you'll see the oil has emulsified and gone creamy like.

I also agree with barossi regarding the pipe smouldering. If I transition from a day in the singles to doing some 5th - 6th wide open I can get enough heat into it to burn off the excess oil. I've also run lean enough to have the bikes power curve dropping flat under load and not had any smoke from the pipe. A lean setup can also cause that too.

In relation to the crank case seal on the rhs, it doesn't really explain why the bike would run poorly in the morning and OK in the afternoon. I would replace this seal and o-ring if you dig deep enough to get to clutch and PV governor. Cases do not need to be split, but the RHS engine case/cover does need to be removed and can be done with the bike laid over on its side. If you are losing significant volumes of oil you can measure what comes out vs what goes in with the transmission oil. If it's being burnt off you'll have the rich smokey condition and poor running along with less trans oil coming out when changing it. I always pour the old oil back into a 1L bottle for a quick crude check.

While a bike shouldn't run with the bung plug in, I must say I have done this too. Bike has fired up a-ok but it's immediately noticeable that the exhaust isn't flowing and I'm sure if you tried to keep it running long enough it would flame out/load up. We've used the method to snuff a husky WR300 that had its kill switch disconnected due to it shorting.

Have you changed filter oil recently? or started over oiling the filters? It's hard to tell by reading if you are saying that the engine just won't rev and is running poorly like it's over fuelling/loading up, or if its mechanically not opening the PV. When my PV stuck wide open the engine truly sounded like a bucket of bolts - not just didn't sound right - it sounded fatal.

Air filter and oil were replaced aprox. 15 hours engine time. Yes the air filter might be over oiled. And yes again, when i say it sounds bad regarding the PV, it's just as you described but only from the point where the PV should open, up until then it sounds and runs fine.

I think it's time to clean the PV and exhaust ports, while i'm at it i'll order new crank seals and change the one on the RHS if you say i won't need to split the cases open. It will take a while tough before i'll be able to post any updates and/or ride the bike to see if it fixed the issue (the seals will take at least 1 week to get here).

p.s. engine oil that is in the bike is motorex, i only used to put in motul but they didn't had any on stock at the time witch might explain the squeaky clutch when the engine is very hot and i start from a stand still

 

[barossi73]

Can you get a better pic of spark plug?
And try draining carb of old fuel in case some water is in fuelbowl.any water in there will make it spit/cough/splutter
You could also pull exh pipe off and turn engine over very slow until piston crown is visible.use torch to look for signs of detonation.dont accidentally start it!its very loud,sounds terrible,and fire shoots out the hole!
Safer than using kickstart is to remove spark plug,put into gear,then rotate rear wheel until piston crown is visible

 

[poelinca]

Can you get a better pic of spark plug?
And try draining carb of old fuel in case some water is in fuelbowl.any water in there will make it spit/cough/splutter
You could also pull exh pipe off and turn engine over very slow until piston crown is visible.use torch to look for signs of detonation.dont accidentally start it!its very loud,sounds terrible,and fire shoots out the hole!
Safer than using kickstart is to remove spark plug,put into gear,then rotate rear wheel until piston crown is visible

Will post pics of the piston crown tonight when i get back home. Here are some better pics of the spark plug. I'll drain the carb and let you guys know what i find in there also.

I took the big camera out to take pics, have a look at them here http://imgur.com/a/BcfQ0

 

[barossi73]

Color looks safe enough,(to me at least).if the color is true in pic...a little rich perhaps
Sorry im not more specific but unless theyre in front of you its difficult,even then... they vary depending on oil type,last ride etc. General indicator only.
Any sign of metal flecks?
Fine grey ring around tip of center electrode is correct ignition timing
If there is some form of oil/coolant contamination the color/cond could be skewed a little also