One side is smoking...

[Jonny Rock]

Hi all,
I have a 2lt air cooled bus that I have had for about 6 years. Always dropped a bit of oil and a little smokey, but over the years has got progressivly worse.
So, out the engine came and all seals have been done. Barrels/pistons/rings checked as well as valve stems/guides and exhaust stems/guides. Everything in good order. Nothing loose or worn. Compression was good before removal, between 120 - 125 across all four.
Engine back in and no more oil leaks.

Runs great, has always been looked after, serviced every 3000 miles etc.

My problem is that one side is producing an awful lot of smoke out of the exhaust,(cheap empi twin), did this before removal of engine but not as bad as it is now. From the back of bus its the right hand side.

Have I missed something else besides what I mentioned above.

Any suggestions as to what it can be would be greatly appreciated.

Many thanks in advance for any answers, Jon

[kevtherev]

How were the guides, stems and the rings checked?

[Jonny Rock]

Hi mate, rings checked with digi messuring thing, forgot what they're call, and guides and stem visually and am assuming the same digi thing.
Have to say, the smoking is not constant, very ramdon. Sometime just on tick over then stops, and other times when when I'm moving up the gears.

Thanks for your response, Jon

[kevtherev]

Have you ran it at motorway speed for twenty mins and checked the plug colour on the smoky side?

[kevtherev]

which carb is the crank breather attached to?

[Jonny Rock]

Will check in the morning, drove up from Bristol Friday. but I do a fair bit M-way driving, summer festivals and hols. But as 1st post, the same side has always puffed out a bit of smoke. Nothing to get me alarmed. But this is now in the BatMan smoke screen territory.

[Jonny Rock]

Breather out the back with a small filter on it.

[kevtherev]

OK it was just a thought

[Jonny Rock]

If plugs are oily, oil is getting through, so do you think the rings aren't as good as I thought?
Gut feeling when I look tomorrow is they will be oily.

[kevtherev]

If plugs are oily, oil is getting through, so do you think the rings aren't as good as I thought?
Gut feeling when I look tomorrow is they will be oily.

get the engine warm then drive it at over 60 for 15 - 20 mins.. pull over or drive it home.. let it cool a bit and pull the plugs out
then pull the other side to have a reference.

if there's one sooty plug then we can go from there, no use speculating

Can I assume you have correct mixtures on both?

[Jonny Rock]

All correct. when engine went back in, timing done and carbs balanced and analyzer up exhaust.
I'll go for a drive tomorrow and check as you sugguest.
I'll post up when I know.
Thanks for you input kevtherev, cheers Jon

[Jonny Rock]

Right, been for a drive today, as suggested by kevtherev, got back and had a look at the plugs on both smoky side and non smoky side.
Plugs on smokey side are a little sooty, but compared with the non smoky side, theres not a lot in it to be honest. both sides look ok.
If I didn't have this smokey problem I would not give the plugs a second look or be concerned.
Any further help would be greatly accepted.
Jon

[dugcati]

which side is the sooty side? is it on the left as you look in the engine bay? This side does all the idle circuit on these so the fuel disance is very short and hence likely to over supply as the carb/linkages etc get older

Not sure but worth checking....is the shut off solenoid at the back of the right hand carb is on its way out and starving the other side of idle fuel?

[Jonny Rock]

Hi dugcati, its the right hand side as you look into engine bay. Plugs not really sooty, but really smokey out of exhaust.
As in earlier post, everything checks out, compression, tuning, timing, valves, stems, rings. Just very smokey on right hand side.
Got replacement solex on from stateside tuning, about 4/5 years old. These have been fine.
Now you mention the starving, I can't remember whether engine smoked on right side before carbs were replace. Also had an original exhaust on instead of the empi twin thing. With the twin exhaust, it very evidently 'SMOKING' on the right.
Oh smoke is a Bluish colour.

[kevtherev]

Good news then
you have a good mixture set up.

the oil you're burning is a small amount but enough to create smoke.
Now
Were the compression figures with a wet cylinder or dry?
was a leak down test done?