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

[Hooli]

Well if the PAIRs seals are leaking into the ports, then oil will run into the combustion chamber when parked for any cylinder where the exhaust valves aren't closed.

[seth]

As hooli said about the seals
It can only be them or the valvestem seals .
If it was rings the piston tops would be all burnt .
Is it just 1 piston ,1 pair (1-2,3-4) or all 4 pisons ?

The pistons look too clean for it to be a massive motor problem .

[Andre]

Hate to jinx you as with the dowel pin.

I assume you have been able to check the PAIR seals and that they are OK. Right?

If so, I would do a leak test. That should help finding any leaks location. I bet valve stem seals gone; but more is possible. As said previously: seals are fairly common issue on very low-mileage old bikes.

BTW, changing the valve-stem seals can be done without removing the head:

[seth]

I've seen that before Andre looks a much better way to change valvestem seals than stripping the top end (along with all the known risks that go with that)
 

[Xdiavel]

As hooli said about the seals
It can only be them or the valvestem seals .
If it was rings the piston tops would be all burnt .
Is it just 1 piston ,1 pair (1-2,3-4) or all 4 pisons ?

The pistons look too clean for it to be a massive motor problem .

Hi,

They're wet across all 4 pistons sadly. My only thought to not think it's the PAIRs seals is that they sit higher up ie out of the oil when the bike is off where the valve stem seals are lower down and probably sit in a lot more oil to be able to leak through?

I understand I suppose that when on engine over run it can pull a bit of oil through the seals then when sat it drips down the outlet.

Never done valve stem seals before so hoping it's not those as will have to do the timing also ie make sure the Cam gears are spot on etc but cannot justify spending any more on it at this time to get a shop to do it. 

[Xdiavel]

Hate to jinx you as with the dowel pin.

I assume you have been able to check the PAIR seals and that they are OK. Right?

If so, I would do a leak test. That should help finding any leaks location. I bet valve stem seals gone; but more is possible. As said previously: seals are fairly common issue on very low-mileage old bikes.

BTW, changing the valve-stem seals can be done without removing the head:

I have seen a couple of methods using string and bringing the pistons up to TDC so the valves do not drop etc. Will have a look at that Vid in a mo

[Andre]

My only thought to not think it's the PAIRs seals is that they sit higher up ie out of the oil when the bike is off where the valve stem seals are lower down and probably sit in a lot more oil to be able to leak through?

Correct.

[seth]

Getting the marks right is straightforward you just need to check and recheck but it's fairly easy.
If you could get the valvestem seals replaced without out removing the head (as per Andre's suggestion) that would be a massive bonus and save loads if cash in the process.
As before I wish you good luck .
Shame your not closer .

[Xdiavel]

Getting the marks right is straightforward you just need to check and recheck but it's fairly easy.
If you could get the valvestem seals replaced without out removing the head (as per Andre's suggestion) that would be a massive bonus and save loads if cash in the process.
As before I wish you good luck .
Shame your not closer .

Cheers Seth,

There are quite a few video's where you put thick string in the bore through the spark plug hole and leave some hanging out and raise to TDC which pushes against the valves and holds them in place while you do each set of 4 so no head removal needed. I do not have an air compressor or tools so unable to pressurise the bores.

Will still try to stay optimistic on the pairs seals lol

[Andre]

The thick string trick sounded good to me. But then I found this comment (pinned by the author) on the 1st video that came up in the search:

!!!WARNING!!! After watching your video I decided to use the 'Rope' as opposed to 'Air'. On BMW S63 engine I stuffed cylinder 1 with nylon rope, turn crank until it stopped, removed valve springs. I turned the crank counter-clockwise slightly to release top of cylinder from compressing rope.  When attempting to remove rope it would not come out. After using my bore scope to view inside the cylinder, it had somehow developed a knot. At this moment the nylon rope is stuck in the cylinder and will not come out, no matter how much pulling force is applied. I picked at it for 4 hours to try to undo know, impossible. I am now in the process of removing the head to get the rope out, which includes removing turbos, all associated coolant and oil lines, then the exhaust manifold. What a mess!!! DO NOT RISK IT!!!

There is another method (also by the author of the first, which I definitely would not dare to try:

Compressors can be borrowed or rented!

[grog]

Diavel, ive done cars using compressed air. All have went well. Doing 14, lot smaller, less free space, fiddly job id reckon. Totally possible. As you do each cylinder,make sure motor is locked up, in gear, you dont want it to turn. A perfect to use spring compressor will be important. Best of luck Mate.

[Eric GSX1400K3]

Same here, have done cars this way. Put the cylinder youre working on at tdc, this way much less chance of the collet and or valve dropping away

[Hooli]

Decades ago there was even a special tool for Ford CVH engines that replaced the rocker to do stem seals this way. We all put RS Turbo ones on as they didn't ride up the stem as soon as you started the engine.

Thinking about it, I've still got that tool somewhere.

[Xdiavel]

Well finally got it back together and sadly it is still doing it :-(

So sadly looks like it's all got to come apart again and torn down for the stem seals.

Not a happy bunny atm but was worth a try

[grog]

Not what you wanted Mate. Would piss me right off. I really doubted the pairs seals.Did it smoke b4 you changed oil? Maybe try diff brand.Big/ expensive job head off. Hire compressor, buy spring tool, have a go with head on. Theres a product Forte seal conditioner, gets good reviews, not sure how it goes with clutch.