My 88 thou has started to burn oil, smokes more when started cold. Been suggested that it could be the valve stem seals or piston rings. Is there any way to tell without dismantling the engine?

 

As general rule,
If you engine smokes all the time especially on acceleration then this would indicate piston ring /bore wear.
If you have a big puff of smoke when you pull away after runnung down a hill where you have been off throttle for a period ( this creates high induction tract vacuum) that is normally indicative of valve stem seals leaking as the vacuum will draw oil into the inlet port.
I suggest you ask someone to follow you and advise you when the most smoke is evident.

 

also if shes blowing some blue smoke at start up its usually a sign of valve seals leaking.

 

+1 for both mentioned above.

 

Hope gas is not draining from your carbs when shut off and thinning out your oil

Can happen easily enough on a MK1 that's gravity fed (fuel pump taken out)

Ask me how I know this ! ..... now I always remember to shut off the petcock
on my 87

 

Thanks for the replies chaps.
Sprock - I owe you a beer, I've just run out and turned the fuel off. Not had the 'burning issue' since I removed the fuel pump... Never would have guessed that could happen.

 

It's a potential cause of the problem man , if it has been doing that you now need
to drain the oil and refill with nice new thick stuff.

Make it (shutting off the petcock) part of your parking routine before the kickstand
hits the ground and you pull the key

This is the only real big "con" to gravity feeding the carbs ! on a MK1

There are aftermarket vacuum operated inline fuel valves that can be added if you find
you'd prefer not to run the chance of forgetting to shut the petcock off

Now if I could only find the link I had for them !


Oh yeah here it is http://www.pingelonline.com/powerflo_9050.htm
http://www.oemcycle.com/Item/product/900058260
http://www.powersportsuperstore.com/...tm?Click=35177


a bit pricey but you get the idea and there are other cheaper ones
just need to make sure they have enough throughput

you'd run a vac line to any rubber capped vac port (used for syncing ) on the carb
bank for acutation (shorter the run the better tho) so that would make it carb 1 or 4
depending which side you elected to feed from when switched to gravity feed

Mines carb 4 side (right throttle side) less prone to kinking of the maine fuel line feed

Now I have you to thank as I just ordered one from PowersportSuperstore
Been meaning to do it for a few months

 

Cheers dude, I'll see how it goes with turning the fuel on and off, got a feeling I'm gonna be stalling on the way to work a few times. I'll see if this cures the oil burning (fingers crossed!).

 

I have had fuel in the oil on bikes before. You can usually smell it on the dipstick.

Wow Sprock! That gismo is a bit $$$$ but if it works it works.

 

Well TBT on an 87 with no vac petcock is can save a few oil changes ! in short order
Time and material - should make it pay itself back soon enough