Backfiring & Air Cooled Specialists round Stockport

[Helga]

Hi, my 2litre T25 backfired the other day, and does not seem to have the 'zoom' it did last week, plus it hesitated on accelaration a little yesterday - what do you think it is? Water in the fuel? Valves? Spark plugs?

Hmnn. mechanical novice willing to give it a go! Or... does anybody know a mechanic / garage around Woodley in Stockport (Greater Manchester) who is air-cooled friendly? I took it to my normal garage and they wouldn't touvh it!

Thanks everybody!

[Helga]

about misfires and backfires - same problems I think, so only need to find a garage plus which bit of the engine to check first if I do it myself with a trusty Haynes manual... cheers!

[jason k]

backfire is caused by timing out , mixture out or airleak.

[phade]

Sometimes a quick cure for this is the old fashioned hand over the carburetor trick to blast out the sediment within the carburetor. This was the case with my 2.0 litre Aircooled.

[Helga]

How does the 'hand over the carb' trick actually work - plus do you need to do both carbs at the same time?

Cheers

[The_blue]

I'd go with timing as well..

[The Reverend Pimp Daddy]

Could be a list of many things....mine was like that for a few weeks...Right carb kept flooding...float was knackered...but it could be the fuel cut off valve...the old carbs could need refurbing, best man for that is Steve at Gasure, Chester.....Really you could be looking for ages, he'll sort it quicker and cheaper in the long run

[Dubstar]

You could try Manchester Aircooled. A friend took his Bay there a couple of weeks ago, and when he collected it it had a new clucth in, and various other jobs for £300. And it was there for ages as my friend was in no hurry to get it back, so he did loads of jobs on the list my friend had left him. I think the guys name is Stefan - 0161 877 5558 http://www.manchesteraircooled.com/index.htm

[Helga]

Manchester Aircooled it is - thanks for the pointer, I'll try them at the weekend. I'd still like to know what the hand over the carb trick is though?

[Laurie]

A backfire can often either blow the manifold elbows off, split them or bash the choke into the carb, causing it to be stuck firmly closed. I've had to take a hammer to one once, it was so well wedged.
If that has happened, the hand over the carb will be a wastte of time.
1:check elbows
2: Take top of each carb and make sure the chokes open easily.

[Dubstar]

Also on mine recently, the bypass cut off valve on the top rear of the LH carb had come loose and was causing mine to run a little funny. Also check that the brake servo pipe hasn't come out of the manifold, also on the LH side. Or in fact, check if any of the hoses and pipes haven't either worked their way loose or split.

[phade]

Hiya Helga,

The hand over the carburetor trick (in a twin carburetor type 2 T3's case) is the following:-

- Undo and lift off the rubber elbow from the left hand carburetor. Leave the right hand carburetor elbow on top of that carburetor.

- Start up the engine

- Put one hand over the top of the left hand carburetor (leaving a small air gap) and rev the engine up and down. This should blast out any sediment or deposits stuck within the carburetor (the engine may sound like a lawnmower as you rev the engine up and down). Be careful not to get your hand sucked into the carburetor !!

- Switch off the engine

- Put the rubber elbow back on top of the left hand carburetor and remove the elbow from the right hand carburetor.

- Repeat the process for the right hand carburetor.

That trick worked for my type 2 T3 (it was a knackered fuel filter that caused the misfiring problem in the first place).

[Helga]

Thanks for all your help everybody - tried some of the sugestions, but still not 100 % happy with my amateur results - so taking it into the garage.

[pollycamper]

We take our Polly to Stefan at M.A.C. He is a top bloke.

[Tex Ritter]

2ltr AC CU engine.

I had a similar problem with backfiring, checked and found the rubber elbows had come off the intake manifolds under the carbs, one goes to the brake servo pipe, refitted them and cable tied them on...everything OK now.