Welcome to the Austin Seven Friends web site and forum

As announced earlier, this forum with it's respective web address will go offline within the next days!
Please follow the link to our new forum

http://www.austinsevenfriends.co.uk/forum

and make sure, you readjust your link button to the new address!

Welcome Austin seven Friends
This Forum is Locked
Author
Comment
View Entire Thread
Re: Starting engine after resetting tappets etc.

Thanks Ian (W), by strange coincidence there was another fault at the same time, the condenser had gone open circuit! This caused considerable delays in arriving at answers.

Jim, I know what you mean but surely the main jet is the brass one covered by a cap at the bottom of the carb?

Ian (M), yes, I had been tinkering with the fuel tap after finding shavings in the carb filter. The 'O' rings have been replaced by cork seals and the whole carb was dismantled and washed out but there must be some small pieces still in there. I intend to give everything another clean today and will report on findings later.

I'm very grateful for the assistance.

Brian

Location: Near M1 Motorway Jtn 28

Re: Starting engine after resetting tappets etc.

Brian, the Viton "O" ring shavings gives the clue that you have recently been tinkering with the petrol tap. This being so, one of my first checks would be that there was a sustained, adequate flow of fuel to the float bowl??

Ian Mc.

Location: Shropshire

Re: Starting engine after resetting tappets etc.

So have you solved the problem Brian, was it simply condenser, or carb as well?

Location: NZ

Re: Starting engine after resetting tappets etc.

Ian, solved the condenser problem, now cleaning the jets etc again to ensure that there are no more pieces of Viton 'O' ring. The battery is now fully charged so just a few more checks and I'll give it a go!
Brian

Location: Near M1 Jcn 28

Re: Starting engine after resetting tappets etc.

There are two jets under brass covers. The main jet is at the top of a long tube, the other has no tube, just a simple jet and that's the compensating jet.
Don't be tempted to poke wire into jets, they don't like it.

Re: Starting engine after resetting tappets etc.

Thanks for the clarification Jim, I checked that jet and found a blockage caused (I think) by a sliver of loose solder from the gauze filter at the petrol inlet. I say "I think" because it blew away when I applied the air gun!
I've replaced the filter, for now, with a nylon one but I don't like the nylon ones because they seem to distort in petrol.
As well as the one you mention at the end of a long tube, mine also has a jet at the base of that tube.
I've now cleaned everything and put it back together ready to try again but a neighbour is (very kindly) insisting on taking me and my wife out to dinner!

Location: Near M1 Jcn 28

Re: Starting engine after resetting tappets etc.

I'm afraid that it's me again! I've managed to get the engine running by using full choke, although I have never needed choke before.
It is running too fast but when I push the choke in, it accelerates and then dies unless I pull the choke out again.
It has run enough for me to set the distributor in a better position but now I need to tackle the slow running.
Any ideas why it accelerates then dies when pushing the choke in, would be most welcome. In the meantime I am checking over everything (without taking anything apart at this stage).
Brian

Location: Near M1 Jcn 28

Re: Starting engine after resetting tappets etc.

Sounds like an air leak. Choke out giving plenty fuel and air mixture so runs slowly and a bit erratic; choke in and momentarily fuel/air mixture becomes just right so accelerates; then air/fuel becomes too weak so stalls.
Worn butterfly spindle (varnish/dirt originally partially sealing worn bits now cleaned off so more air leaking in); Good seal at base of carb.?....check for curved base which may need filing flat.

Location: Devon

Re: Starting engine after resetting tappets etc.

My car does this when it is first started from cold. The reason in my case is that the choke on the FZ carburetor is extremely crude. The choke closes off the air intake almost completely so the engine cannot rev. Releasing the choke allows it to rev and run for a bit but the enriched mixture is soon used up so the revs drop and it stalls unless the choke is applied again.
I have to run it for a while closing and opening the choke a few times until the engine has a bit of heat. It then keeps running if the hand throttle is opened slightly to give a raised tickover. I always start from cold with the handle throttle opened slightly.
Once the engine is warm it ticks over very nicely.
If the problem persists even when the engine is warm then there is some fuel starvation, possible main jet again.

Re: Starting engine after resetting tappets etc.

Followed what you said Jim and had the same result! Engine revs are still too high but I'm working on it and at least it will now start on the handle.
I may make it to Autokarna yet!
Brian

Location: Near M1 Motorway Jtn 28

Re: Starting engine after resetting tappets etc.

Have you checked your carb/manifold flanges for bowing and air leaks?

Location: Piddle Valley

Re: Starting engine after resetting tappets etc.

Check the carburettor mounting flange for flatness Brian, it sounds like you have a bad air leak and I've yet to see a flat mounting flange on any 22FZB I've acquired. For a picture of the 22FZB see Barry Riseley post of June 30 2017.

Re: Starting engine after resetting tappets etc.

Dave Mann
Check the carburettor mounting flange for flatness Brian, it sounds like you have a bad air leak and I've yet to see a flat mounting flange on any 22FZB I've acquired. For a picture of the 22FZB see Barry Riseley post of June 30 2017.

Dave, you had me worried there! June 30 2017??

I can find only one post by Barry but that is about a Zenith 24 T2 carb

I'm off to check the flatness now!
Brian

Location: Near M1 Motorway Jtn 28

Re: Starting engine after resetting tappets etc.

Sorry Brian it is 2007, I just Googled Zenith 22FZB carburettor and found the thread almost immediately.

Re: Starting engine after resetting tappets etc.

I'm very grateful for the suggestions and decided to ensure that all the joints are flat. I've had the exhaust manifold on the miller for a light skim both sides, the problem here was pitting corrosion.
The carburettor faces were check but only needed a light linish.
The inlet manifold I had thought was good but examination revealed that, whilst a check along it indicated no problems, a check across the carburettor joint faces showed considerable errors which a couple of hours of hand sanding with a piece of sanding belt glued to my surface table has improved it no end it could do with another one with more metal on the faces.
I'm now getting ready to reassemble and picked up a NOS tube of Holts jointing compound at Wollaton to assemble things with. I had a smell of it and it has the same smell as 'Osotite', of which I have a small can in the workshop. The stuff I have been using was like Blue Hylomar but does not stay flexible, despite what It says on the tube.
I 'll let you know how I get on.
Brian

Location: Near M1 Motorway Jtn 28

Re: Starting engine after resetting tappets etc.

SUCCESS!!!! Many thanks to all on and off this forum for help and advice. The car started on the first swing of the handle today and just needs some very minor adjustments to make it run really well.
The worst out of flatness on the inlet manifold was underneath where it was very difficult to place some thick oil to see if that revealed the leaking air. Just need a longer run to satisfy myself that all is well and then a short run on Saturday or Sunday to the Belper Steam Fair near Denby in Derbyshire, might even be the odd Austin.
Brian

Location: Near M1 Motorway Jtn 28

Re: Starting engine after resetting tappets etc.

Well done Brian, glad you got there in the end

Location: NZ

Re: Starting engine after resetting tappets etc.

Maybe I'm unlucky but every Seven engine part that is supposed to have a flat mating face that I've come across is anything but flat. Crankcase top faces are the worst usually exhibiting fretting damage from loose blocks and or starter housings, while every exhaust manifold has had a distinct hollow in the centre. So it is has been standard practice to check all mating faces before use.