Oil Burning Mystery

[dazbaby]

Hello,
I have an SLR650 and I am very happy with it apart from poor quality forks (pitted) and an annoying problem whereby oil seems to be getting burnt withing the engine, but is only emmited via the one of the silencers, not both.

The bike has only done around 9500 miles and I would not have expected any wear issues at this mileage, but I could be wrong as I am not too familiar with this engine or bike.....new owner.

Could anyone please tell me what might be the cause?

Thanks and regards
Darren

[truxx]

Hello,
I have an SLR650 and I am very happy with it apart from poor quality forks (pitted) and an annoying problem whereby oil seems to be getting burnt withing the engine, but is only emmited via the one of the silencers, not both.

The bike has only done around 9500 miles and I would not have expected any wear issues at this mileage, but I could be wrong as I am not too familiar with this engine or bike.....new owner.

Could anyone please tell me what might be the cause?

Thanks and regards
Darren

Fork pitting can be easily fixed using some araldite then covering with fork gaiters.

The burning oil is probably due to piston ring/valve seal problems.Best thing to do would be a compression test to check for sure which it is.

I have a compression tester and some aradlite and i'm only a few miles from you if you need any help

Thanks
Dave

[dazbaby]

Thanks for the kind offer Dave.....I had forgotten about the Araldite fix for pitted forks.

I do have a compression tester myself; again thanks for the offer, but wondered whether there was any known weak points with these engines with regards to valve stem seals or the valves themselves.

The fact that the smoke is only being emmitted from one exhaust kind of leads me to valve seals rather than piston rings which would probably result in smoke from both exhausts.

Anyone shed any light on what the cause probably is?

Cheers
Darren

[switch]

Thanks for the kind offer Dave.....I had forgotten about the Araldite fix for pitted forks.

I do have a compression tester myself; again thanks for the offer, but wondered whether there was any known weak points with these engines with regards to valve stem seals or the valves themselves.

The fact that the smoke is only being emmitted from one exhaust kind of leads me to valve seals rather than piston rings which would probably result in smoke from both exhausts.

Anyone shed any light on what the cause probably is?

Cheers
Darren

Mind you, because of the automatic decompression system, you'll have to manually adjust one of the exhaust valve clearances to a very small value before doing the test. Otherwise, the compression test is almost irrelevant.

[IgorVigor]

Valve seals do seem a common fault on these engines....

Also, riding style can affect oil use...

and so many other factors :P

[dazbaby]

Hi,

Thank you for the replies......looks like the top end of the engine has to come off then.

Is it a straight forward DIY type job to do stem seals and can you buy just the gaskets required or in typical motorcycle rip-off style....purchase a full gasket set at over £50!!

Cheers
Darren

[MadWelshBiker]

I think this engine is the same as the Dominator/NX650. The head gasket is about £20 and the rocker box gasket about £18. The seals are a couple of pound each if I remember correctly. The main problem is that sometimes the rocker box cover bolts snap. The cover comes off over the back of the engine where the carb is or was as you have to remove that first. The seals are easy to replace once you have the head off and the valves out. I'd take the opportunity to lap the valves in once they are out. If it is not burning a lot of oil I would be tempted to leave alone until it got real bad as it sounds like it is an exhaust valve seal gone and so any burnt oil is going directly into the exhaust and shouldn't affect performance. If you do take it apart make sure that you label each bolt as it comes out as there are about 5 different lengths holding the cover down. Also think about replacing them with stainless steel, you'll need SS washers as well. I bought mine locally for pence.


Good luck

Mike

[IgorVigor]

Honda SLR 650 V/W 97-98 Replacement Parts at Wemoto

I have used wemoto for several bikes now, and never had a problem with the parts...

Hope this helps...

[dazbaby]

Hi Again,

Thank you very much for the input lads......very helpful and appreciated.

Regards

Darren

[Rubberchicken]

If you decide to take it apart...

Get a sheet of cardboard, roughly sketch the head outlines on it, and stick the bolts through the cardboard in the right locations. Most of them are different length, and it's a bugger to keep them apart otherwise.

Also, get a decent torque wrench in a low range, say 5-30 Nm, the head is the major major major weak point on this engine, the aluminium is weak, threads strip at the slightest provocation, and on top of that there's possible head warpage. Keep a box of helicoils ready...

Mine's got valve seal problems and so far I've left it alone. It runs A-ok on the backroads with about half a liter consumption per oil change (2000 miles) as long as I stay off the motorways. (On longer motorway runs it drinks like nothing else, though.)

How much oil does yours use, roughly?