Bike Smoking when coming off revs, Rider behind said smells very rich after new

[Xdiavel]

I will try another compression test Saturday when it's warm and see what I get.

But  by the way She pulls I don't think there is much wrong power wise.

[KiwiCol]

Your pairs are as new looking, hmmm, well as a no cost possible solution, consider doing the pairs delete mod & see how it goes, you can always just connect everything back up if it's no different, but many just remove the pairs system, block off the hoses & covers with no issues.

Just thinking that oil is getting in somewhere & it could be through this system.

[grog]

To try with pairs disabled, just block its inlet hose at airbox. Marble or similar. Other thought have you tried a different oil brand? Might sound stupid but once had a work ute, changed brands and blew smoke, changed back and came good.

[KiwiCol]

Grog, go back 5 posts on the previous page (earlier this morning)  I was also saying about Oil, reco Gulf Western 3000

[KiwiCol]

I keep re-reading.   9,000 miles!   That's bugger all for a bike of this vintage.  Wonder if the bores are glazed over  -  from boredom?  Perhaps some running in oil and a good Italian Tune Up for a few hundy miles then change oil back.  Reckon that's why you can't find a fault, once the oil gets hot & thin it gets past the rings at times.  Comp would be good cold too.

[Andre]

f you look back at my cylinder picture, to me it looks washed out ie too clean. And a puddle of oil or possible fuel on top. This was on all cylinders if memory serves. But zero smoke when cold started.

Rider behind said smells very rich

Sounds like overfuelling at higher engine temp. Oil temp sensor the most likely cause. Have you checked/replaced it?
Pics show imo clear wash-out from too much fuel.

[Kiwifruit]

Hi, I am running Motul5100 10w/50
[/quote]


I ran that stuff for a few oil changes. Wasn't happy with the way the gearbox felt. So as per Grogs advice changed to Gulf Western syn-x3000 10w40. Used it now for 100,000kms with 5000km oil and filter changes.
I only fill to half way between the marks when its on the centre stand. When the bike is on the ground after being filled to the top mark while on the centre stand I reckon it looks over filled.

[grog]

Col, i did oil experiment on old org. 2 years of testing, all disappeared when org failed. I remember the dearest, Motul, i remember the worst gear change, Motul. All IMO

[Xdiavel]

Thanks for all the replies guys, I do really appreciate it. I had a tinker with the TPS last night just in-case it wasn't quite right, Waste of time really as it rides like new through the whole rev range.

But ran it up again while working from home and bang on queue at 80deg oil temp it starts smoking when revved.

I had a board of wood up behind one of the tail pipes and gave it a few revs and could not see any oil spits on it. I then held a bit of kitchen role scrunched up against one of the pipe outlets and smoke really did show up around the paper when slightly blocking it. Again no oil spitting just a light brown dirty looking stain on the paper.

The smoke is light white in colour, I wouldn't say blue for oil but then I wouldn't say Black for over fuelling either.

Kind Regards

[Xdiavel]

f you look back at my cylinder picture, to me it looks washed out ie too clean. And a puddle of oil or possible fuel on top. This was on all cylinders if memory serves. But zero smoke when cold started.

Rider behind said smells very rich

Sounds like overfuelling at higher engine temp. Oil temp sensor the most likely cause. Have you checked/replaced it?
Pics show imo clear wash-out from too much fuel.

hi Andre,

Thanks for commenting. I did test this last year but as I have just ran the bike up to 80deg I though why not test again when hot.

Interestingly it is only showing 3.8 Kohms at 80deg where the Manual states it should be showing 6.2 kohms at 80 deg. Bu that could be my temp gauge showing slightly out also.  mmmmmmmmm

Engine Oil Resistance Temp.
 20°C( 68°F) Approx. 61.3 kΩ
 50°C(122°F) Approx. 17.8 kΩ
 80°C(176°F) Approx. 6.2 kΩ
 110°C(230°F) Approx. 2.5 kΩ

[Hooli]

Those figures for the oil temp sensor look roughly right from memory.

Is it actually burning enough oil to need topping up when ridden regularly? white smoke says water to me, but that doesn't make sense on a 14 unless the oil is full of condensation & you'd notice that quickly enough in the level window.

[Andre]

Bu that could be my temp gauge showing slightly out also

If you took the temp from a "screw-in" temp gauge, then all bets are off. The difference between screw-in and the point where temp is taken for the fan switch is in my case 15-20 °C. No idea what the temp difference between "screw-in" and EOT-sensor would be, but I expect it to be higher at the location of the sensor. The way to test the EOT-sensor is outside the bike.

As oil temp increases and kΩ decreases, fuel amount decreases. With your kΩ lower than expected (likely to be correct considering the location and thus higher temp), I'd say that the sensor is working ok.

There are some other things to test. See manual at page 4-37.

As the problem appears temp related, I would also check the IAT-Sensor.

[Xdiavel]

Bu that could be my temp gauge showing slightly out also

If you took the temp from a "screw-in" temp gauge, then all bets are off. The difference between screw-in and the point where temp is taken for the fan switch is in my case 15-20 °C. No idea what the temp difference between "screw-in" and EOT-sensor would be, but I expect it to be higher at the location of the sensor. The way to test the EOT-sensor is outside the bike.

As oil temp increases and kΩ decreases, fuel amount decreases. With your kΩ lower than expected (likely to be correct considering the location and thus higher temp), I'd say that the sensor is working ok.

There are some other things to test. See manual at page 4-37.

As the problem appears temp related, I would also check the IAT-Sensor.

Hi,

I tested that while I had the side panel off and that checks out ok too.

I am going to do the pairs block and compression test the weekend and take it for a ride. My guess will be exactly the same as the pcv system and airbox are very clean.
If you look at the piston picture I posted early in the thread, on the far left there looks to be a little pool of oil or petrol  but looks more oil to me.

I might just do the rings anyway, at least it will tick that box. After that if it still does it, then it's going up in flames hahaha 😆

God knows what previous owners have done to this.

[Hooli]

Just a thought, you can get good compression with duff oil rings. But I really can't see that happening over all four cylinders equally.

[Barbastro K6]

When releasing the throttle and closing throttles, a strong suction of oil is made between cylinder and piston.


If you suspect, there could be a piston ring stuck together that allows oil to pass through.
perhaps because of a "very smooth" conduction or because of the quality of the oil or because its base is very mineral, not synthetic