Club 80-90 Forums

Setting up the timing and tuning the carbs really is easy to do. Unfortunately the owners of air-cooled VW fall mainly into two camps. The ones who own a Beetle / T2 as a cool fashion item and are happy to throw money at shiney bits and rely on air-cooled specialist to keep them running. Or the people who are prepared to get their hands dirty and don't go anywhere without a bag of spanners.
It's up to you, £200 either buys you a few hours of a mechanic's time, or it buys you a timing light, vacuum gauges, spanners & screwdrivers.

cool fashion item

bit unfair im just not mechanically minded with engines ! ( I am a mechanic of bicycles though !)

Timing...
Think of a bomb.
The bomb goes off at 4 minutes Before the top of the clock

Or 4 degrees Before Top dead centre.

Because the speed of the piston on its way to the bomb is so fast by the time the bomb goes off, the energy release is late. So late, the piston is on the way down the bore... The bomb helps it go faster.


As the piston moves even faster, the bomb has to go off even earlier because of the delay in energy release

So we advance the bomb explosion

I think I understand

So its way off the mark then ?

bit unfair im just not mechanically minded with engines

The comment wasn't aimed at you. It was more to make the point that in any business you try to charge what the the market will bear. A certain proportion of air-cooled owners are happy to throw cash at their "cool" vans and garages are happy to take it off them. Hence the £200 to do a simple job.

If you can index the gears on a mountain bike you can set the timing on your van, you just need some different tools.

sternal wrote:I think I understand

So its way off the mark then ?

I don't know, but a timing light will tell you.

It will tell you if your bomb is going off too late and wasting the energy on a piston dissapearing down the bore...or too early and slowing it down.

Timing the bomb right gets all the energy from the bang to the wheels.

fair point its been a long day !

So its way off the mark then ?

The distributor is a switch that controls when your spark plugs fire. By rotating the the dizzie you set the starting point for the switch to open. That gives you a static timing point normally around 7' BTDC. The vacuum pipe that connects to the retard side of the dizzie pulls this starting point back to 5'ATDC. This makes the engine easier to start and helps with the emissions. It doesn't have any effect on performance. The vacuum pipe that connects to the advance side of the dizzie pulls the timing point the other way. As you open the throttle the retard signal stops and the advance takes over making the plug fire earlier. This gives you smoother acceleration when you stamp on the throttle. Finally the biggest effect is the mechanical advance. This is controlled by weights in the dizzie that advance the firing point as the revs increase. This moves the firing point by about 25'.

If either of the vacuum connection don't work the van will still run acceptably if the timing is set at 7' BTDC and the mech advance still works.

If the mech advance doesn't work, but the vac advance does the van will run quite happily at low RPM, but as the vac can only advance the ignition 12' you'll have little top end power.

ah it makes perfect sense !

Thank you for taking the time to explain I have two/three things to be done really

1 Compression check

2 Timing

3 carbs check

My mechanic is great but I guess maybe this has to go to someone that works with VW day in day out and who's honest and near me !

Even I'm bored of this post now !

Setting up the timing and tuning the carbs really is easy to do.

I wouldn't say 'really' easy... but doable with guidance. To be fair unless the carbs are in top nick, they're not too amenable to setting up accurately anyway.

Go see Luke Theochari at Terrys beetle services in Hanwell if your not sure about having a go yourself hes been around Aircooled vws along time.

sternal wrote:ah it makes perfect sense !

Thank you for taking the time to explain I have two/three things to be done really

1 Compression check

2 Timing

3 carbs check

My mechanic is great but I guess maybe this has to go to someone that works with VW day in day out and who's honest and near me !

Even I'm bored of this post now !

Ahem... That's what I said at the top of page 5.

£200 for a tune up??? If you get stuck take a trip up the A1, I'd fix it for far less than those Southern robbing buggers (even factoring in your fuel cost to get here).
Or buy THIS, THIS and THIS. £60 for all the kit you need to do it yourself! Then we can finally put this thread out of it's misery.

Or failing that take it to a recommended local garage!

I've had my T25 TD 1.6 11 years, am not mechanically minded and been to every garage in North London and quite a few south of the river too. Ripped off yes. The last garage I used before I moved to Wales is Chris Cross Motors. And they were by far the best I had found. Efficient and reasonable and Knowledgeable (as far as I was aware) compared to where I'd taken her before. I would be interested to know others opinions on this? Hope you get yours sorted.
Abbie

If you live a mile from Chris Cross, take it to him. Lovely bloke, not expensive, and will talk you through how things work if you ask him. Gets busy though so book in advance.

Failing that, try Andy at Beetlemania in Muswell Hill.