60-70mph for 80mile straight ride cause white smoke.

[syafi]

Ok, I ride each week 250 miles,
normally at 50-55mph for an hour~ and back also 50-55mph for an hour~ ride. twice a week. I have no problem with the bike then.

But I also made 60-70mph ride for 1-1.5 hour straight about once a month, and I can see white smoke from the exchaust. ( after 1 way ride ~80 miles , ) when i came back home also got this smoke.

This smoke dissappear after the bike is rested overnight.

2 time already same problem.... I thought, something bad with engine etc, and ask mechanic to take a look and he says nothing wrong with the engine. but then, if the engine is bad then the smoke should appear all the time right?

I use 20-50 mineral oil then, http://www.petronas.com.my/internet/...04T%202000.pdf

can engine oil become too hot and vaporise? ....

This is the reason i thought of reducing engine speed with smaller rear spocket as i ask earlier..I should have been more specific why i want to reduce the engine speed earlier.

[scotty]

what color are your spark plugs??

[syafi]

These are the plug.
1 is a bit dark , ( still more tan in it , the other is tan.

[Road_Clam]

Re: 60-70mph for 80mile straight ride cause white smoke.

Ok, I ride each week 250 miles,
normally at 50-55mph for an hour~ and back also 50-55mph for an hour~ ride. twice a week. I have no problem with the bike then.

But I also made 60-70mph ride for 1-1.5 hour straight about once a month, and I can see white smoke from the exchaust. ( after 1 way ride ~80 miles , ) when i came back home also got this smoke.

This smoke dissappear after the bike is rested overnight.

2 time already same problem.... I thought, something bad with engine etc, and ask mechanic to take a look and he says nothing wrong with the engine. but then, if the engine is bad then the smoke should appear all the time right?

I use 20-50 mineral oil then, http://www.petronas.com.my/internet/...04T%202000.pdf

can engine oil become too hot and vaporise? ....

This is the reason i thought of reducing engine speed with smaller rear spocket as i ask earlier..I should have been more specific why i want to reduce the engine speed earlier.

Burning oil will emit a slightly bluish smoke. Wipe the inside of your pipe with a rag, burning oil will leave a black wet residue. Pull the plugs also, if they are sooted black, you are sucking some oil. In my experiences with engines internally leaking oil, they will emit a puff of smoke when you first start them up, after they have been sitting for a while, like overnight. Usually bad intake valve seals in the culprit.
Rich

[syafi]

they will emit a puff of smoke when you first start them up, after they have been sitting for a while, like overnight. Usually bad intake valve seals in the culprit.

That dont happens, after resting the bike wholenight no more smoke come. it came only when i made the 60-70mph jurney ~120km.

[scotty]

what is the air temperature you are driving in--im just taking wild shots. is sounds like gas not being burned but your plugs look ok to me at least--even a bit lean. If you ride a short distance in humid air, then stop a bit, there may be condensation forming whicj manefests itself as sater vaporizing

[syafi]

Its hot for sure, room tempreture would be ~30-33 degree Celcius. outside would be much more. but no idea how much.

Humid, not very dry & not very wet, just normal.

The smoke never come except for that 2 occation i ride 80miles for 60-70mph. I am due to do that ride again in 1 week time so i am worried again

[mark]

I had an old Honda CB750F that I let idle way too long once in a traffic jam on a hot day. When it got way too hot, white smoke began just pouring out the back. When it cooled there was no more problem. Not sure why the smoke was white, but it was and there was plenty of it and the problem was overheating.

[IanFrancisco]

White smoke is burning oil. Black smoke is unburned fuel (rich running). The smoke might possibly be from the engine running hot during the 1hr at 60mph. The overheating might possibly be from the bike running too lean at mid throttle openings. If the bike was originally a US bike, it may have a spacer in the needle assy. to lower the needles and lean out the midthrottle operation of the carb. This spacer should be removed to make the bike run correctly at mid-throttle. Also checking the plugs requires a "plug chop" test. Run the bike at the speed and throttle opening that you suspect is causing the problem for a minute. Pull the clutch and turn off the engine. Coast to a stop, pull the plugs and check them then to see the condition. White plugs indicate a lean running condition. Black sooty plugs indicate a rich condition. Do this where it's safe! (light or no traffic)If you wait till you get home to check the plugs they will not reflect the condition that is causing the smoke. You may need to rejet the carbs. Stock main jet size is 115 and pilot is 17.5 which is what I have on my bike also with stock exhaust and stock airbox and filter. The spacers has been removed on my carbs. Maybe going up to a 117.5 or 125 main jet would help. Also I would not run 20/50 mineral oil unless the temp. is very hot, more than 95F/35C. Synthetic 10/40 is best IMO (in my opinion). Also oil deigned for motorcyles is better than regular car oil.

[flyingace]

You need to track how much oil you burn over the next 1000 miles. If it's a quart or less, you are probably OK. If more, it's being comsumed faster than should be - and it will get worse.

[Ions001]

Okay, now I know that some people ( Scotty ) aren't going to like what I'm about to suggest. I had a similar, but more severe, problem. When I ran the bike at over 5000 rpms for more than 10 minutes, it would put out tons of white smoke.

What resolved it for me (your mileage may vary):

I removed the plugs and put 2 tablespoons of Marvels Mystery Oil in each cylinder and let it sit overnight. Before I put the plugs back I turned it over a few times. Replaced the plugs, changed the oil and filter.

That's all that I've done, but I can now ride it like it's stolen and no smoke at all.

[IanFrancisco]

Scotty must know more than I do about Marvel Mystery oil cause I don't know what harm it would do but it sounds like in your case the rings were sticking and the MM oil freed them up. I had sticky rings in an old Honda XL175. If it sat too long, there would be less than normal compression and rattly sounds, but after a ride all would be back to normal.

[syafi]

My mechanic propose a simple sollution, because he said
better not mess with the carb unless its really important.

He never fix a GS before mine, but he is not afraid to fix
any bike though.

he told me to pour a bit 2T oil in the fuel tank, to make
the head cooler. so as mark and Ian says, this is due
because the engine is too hot, so that 2T oil might solve
the problem right?

How do I know if the bike is US Model or European model?

The Engine oil I use is motorcycle Mineral Engine Oil.

[SqDancerLynn1]

Plugs don't look too bad, Just a guess is that running at the higher RPM the oil does not have time to completely drain from the cyl head & floods the valve guides with oil causing the smoke. Lower RPM allows more drain back time, no smoke

[mark]

Hmmmm. Interesting idea..........