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Hopper78

Member

• Jun 18, 2020

• #1

Petrol Series 3 2.25

Hi, I'm getting popping/spluttering from the exhaust and lacking power when going up hills and if using each gear fully/high revs.

I've replaced spark plugs, leads, coil and a new distributor from simonbbc. Setting up the distributor if I retard it the spluttering goes away but it doesn't run very well and is difficult to start. Advancing it slightly so the revs are high at idle increases the spluttering and popping.

I'm thinking it's probably carb related - it's got a pattern carb on it, I have got an original Zenith 36IV but it floods - I'm thinking of rebuilding it as per the autoexpress article.

Could it be anything else?

Cheers

 

kermit_rr

Very

Full Member

• Jun 18, 2020

• #2

First off, of replace the points and condenser, cheap and easy. A bad condenser can give all sorts of running issues

 

kermit_rr

Very

Full Member

• Jun 18, 2020

• #3

Also is the advance vacuum pipe in good order?

 

Shippers

Well-Known Member

• Jun 18, 2020

• #4

kermit_rr said:

First off, of replace the points and condenser, cheap and easy. A bad condenser can give all sorts of running issues

Click to expand...

He's fitted a new dizzy with what sounds like an electronic one from simonbbc...

 

Stanleysteamer

Well-Known Member

Full Member

• Jun 18, 2020

• #5

Strip the carb down, ensure all jets are clear, also make sure there are no leaks at the inlet manifold, (Check by spraying eazistart around it, if the revs pick up, you have a leak.
Also check the new dizzy is the exact right one for your engine and that it therefore has the correct springs on the centrifugal advance.
Best of luck.

 

Shippers

Well-Known Member

• Jun 18, 2020

• #6

Did it have a ballast resistor on original set-up if so needs to be removed if youve fitted a powerspark dizzy from simonbbc...

 

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John S

Well-Known Member

• Jun 18, 2020

• #7

Before doing any of that, pull the idle jet and clean it, blow it through to clear any carbon build up. The symptoms are classic clogged jet, the engine is actually cutting out on overrun but it’s not apparent and the spluttering is it kicking back in again. If it persists you need to retune the carburettor. I’m not familiar with Zenith but you’ll be able to download from google. If you’ve changed all the ignition components it points to this.

 

Lionhound

Well-Known Member

• Jun 18, 2020

• #8

Oops sorry. Saw the title and thought it was another Boris Johnson thread.

 

C

Colthebrummie

Well-Known Member

• Jun 19, 2020

• #9

,might be worth checking the valve clearances anorl.

Col

 

H

Hopper78

Member

• Jun 19, 2020

• #10

Ended up rebuilding the original Zenith I had, then made slight adjustments to distributor/mixture screw/idle screw and all seems to be running smoothly now.

I've opened up the Zenith copy that was on the engine and the little circle disk (not sure on the proper name!) that sits on top of the accelerator pump was caught underneath the circlip - I'm wondering if this attributed to the poor running.

(used this guide https://www.autoexpress.co.uk/land-rover/100752/how-to-rebuild-a-carburettor-zenith-36iv-pictures)