Help - Fire in me Carb, 2.0 A/Cooled

[steveflook]

Am having a nitemare with our 2.0 Aircooled, CU Engine with twin Solexes.
Have checked and cleaned as much as I can and finally got it ticking over in a fashion. Feeling a bit pleased I gave it some revs whilst looking down into the left hand carb and at high revs its popping and I can see fire in there. Sure this aint right lol. Is this a timing thing ? ie firing before inlet valve has fully closed ? Spark plugs on 1+2 cylinders looked like they were overheating, and 3+4 cylinders had carbon fouling.
Also at low revs just before it wants to stall, the engine shudders like heck. A quick tickle of throttle and it will carry on ticking over.

Done a compression test just before to see what I was dealing with and the results are very interesting :-

Cylinder 1st test 2nd test Wet test
1 = 90 psi (Just over 6 bar) 100 psi (7bar) 130 psi (9bar)
2 = 100 psi (7 bar) 105 psi (Just over 7 bar) 131 psi (9 bar)
3 = 131 psi (Just over 9 bar) 132 psi (Just over 9 bar) 172 psi (Just over 11 bar)
4 = 140 psi ( 9 and 3/4 Bar) 140 psi ( 9 and 3/4 bar) 180 psi (Just under 12 bar )

Then, when I turned the engine off a small whisp of smoke came up through the right hand carb. Was expecting Aladdin to appear lol

Came home and studied the Wiki and archives so furiously forgot me dinner was in the oven and sizzled that too.

Still, at least the Saesneg have scored. Am unwaith yn dod ar Lloegr

[steveflook]

Hi all, anyone got any ideas about seeing flames in the carbs ? Is my timing out ? Am at the headscratching stage

[ermie571]

No ideas to help, mate.

The Aircooled gurus's will be along soon I am sure.

if not, you could try calling elite VW in basildon tomorrow - they can be helpful over the phone - particularly with your compression results, showing one side lower than the other.

Good luck with her

Em
xx

[sarran1955]

Hello,

1 and 2 are a bit down.....

Try squirting a bit of oil into the cylinder and see if this bucks things up a bit for the compression test.

If there is no improvement, then your valves are suspect

Fire in the hole , spitting and smoking are signs of either a very badly brought up engine..

Or badly adjusted valves. It is very easy with hydraulic tappets for the pushrod to not sit properly in the recess ..

You will find that the offending pushrod makes it necessary to wind out the adjustment far too much.

A good test, having checked that the pushrod is properly seated, ( a bright little torch helps, )...

is to take the plugs out, (use a bit of rubber hose to guide them back in,) and crank the engine over by hand, there should be no hard spots

Cordialement,

[steveflook]

Hi and thanks for the replies. So does the engine have to come out to check the pushrods and tappets ?? The Haynes manual just says engine removal is not difficult lol.
Been spoilt by 3 years trouble free and now paying the price it seems

[jason k]

nope it can stay in situ.

re do the comp test with a little oil and see the results before you go pulling it to bits.

[jason k]

could also be indicative of a inlet manifold gasket failure. try squirting some wd40 round the area with the engine running and see if the engine note alters, if its sucking in the wd you will soon hear it

[steveflook]

Thanks for the info Jason. I can now see how the rocker covers come off from underneath the van.

Re the compression test, I did put a capful of oil down each cylinder for the wet test, and it gave me on average an extra 35psi per cylinder, but thought this was telling me my rings may be worn ??

Also tried the wd40 spray thing but its a bit hard to tell as I`m a bit deaf lol. Will try again with someone else to listen.

I love my van but I love it more when it works