24 replies to this topic

[Steve66]

Hi

I have just finished rebuilding my 1330 engine with following spec and it coughs bad around 2000rpm. I have rebuilt the carb and float etc all set up to the manual.  It is possible to drive through it if you put your foot down but as it’s a brand new engine want to run in

 

I have tried everything I can think of so any ideas greatfully received

 

1330cc

mg head, unleaded new valves etc

Minispares evolution 001 cam (similar to mg cam I am told)

Minispares evolution electronic distributor 

standard new rockers

timing 8deg

compression about 10:1

running on super unleaded

HIF 44 with BDL needle

Minispares cone filter

Don’t know make of exhaust but is centre exit about 2” diameter twin box steel

 

 

tickover is quite lumpy and runs on

 

thanks

Steve

Edited by Steve66, 18 June 2024 - 01:03 PM.

[Ethel]

Too much static advance?

 

If it's running on, without really warming up, it must be close to detonation.

[corrado vr6]

I too have similar but slightly opposite to you, mine bogs down in the lower rpms and then comes alive at 2000rpm.

Have you checked the dash pot oil and what oil did you put in?

[Steve66]

I too have similar but slightly opposite to you, mine bogs down in the lower rpms and then comes alive at 2000rpm.

Have you checked the dash pot oil and what oil did you put in?

Hi dash pot oil is 20/50 which I have used for years with no problems 

 

thanks for the suggestion though 

 

I have a feeling it’s the needle but no idea which way to go

[Steve66]

Too much static advance?

 

If it's running on, without really warming up, it must be close to detonation.

Hi it only runs on when hot

 

strangely it needs choke for cold start and then is instantly too rich with choke and only runs without choke

[Ethel]

How quickly does it get hot though.

 

With any needle you ought to be able to get some improvement in a specific spot. In a stooped ******* is right twice a day way.

 

The hif choke is separate, so has more effect the nearer you are to closed throttle. Sounds unlikely to your problem though.

[Steve66]

How quickly does it get hot though.

 

With any needle you ought to be able to get some improvement in a specific spot. In a stooped ******* is right twice a day way.

 

The hif choke is separate, so has more effect the nearer you are to closed throttle. Sounds unlikely to your problem though.

It gets hot fairly quickly.  The engine is still tight though.  Only 50miles so far

[Steve66]

What would be the best needle?

 I have just done a plug chop after a run and plugs are a bit on the rich side

[lippo]

 The BDL needle is the standard MG Metro needle. I 'think' my 1275 is an MG Metro engine, and has a BDL needle in the HIF44. It ran super rich when I bought it. I've backed it off 1 1/2 turns and it still runs rich. BER is a leaner needle, but it's difficult to tell what you need unless you can find out what your emissions are (mine was 8% at MOT, so way over 4.5% limit).

 

 Have you tried moving the dizzy clockwise/anti clockwise to see if the car runs better? The timing may be the issue. I'm certainly no expert though. 

[lsto]

Call AC Dodd or someone similar to set it up and tune it. If you have spent a fortune on it then spend a little more and get it set up correctly, no point in all that money if your not getting the best out of it. Plus if the fuelling is out you could wash out your engine.

[lsto]

https://youtu.be/oir...7OFZsf72l_-rBuI

Funny enough @ACDodd has just done a vid on borewash.

Edited by lsto, 18 June 2024 - 07:22 PM.

[croc7]

 

I too have similar but slightly opposite to you, mine bogs down in the lower rpms and then comes alive at 2000rpm.

Have you checked the dash pot oil and what oil did you put in?

Hi dash pot oil is 20/50 which I have used for years with no problems 

 

thanks for the suggestion though 

 

I have a feeling it’s the needle but no idea which way to go

 

Try this website; Su Midel Haystack   a terrific tool to help with needle selection

[KTS]

 

 

I too have similar but slightly opposite to you, mine bogs down in the lower rpms and then comes alive at 2000rpm.

Have you checked the dash pot oil and what oil did you put in?

Hi dash pot oil is 20/50 which I have used for years with no problems 

 

thanks for the suggestion though 

 

I have a feeling it’s the needle but no idea which way to go

 

Try this website; Su Midel Haystack   a terrific tool to help with needle selection

 

 

https://sucarb.co.uk/needle-comparison

 

as mentioned above, until the rings have bedded in properly you should be aiming to run with the mixture on the lean side to avoid bore wash

[corrado vr6]

How new/clean is your fuel tank?
Do you have any inline fuel filters before the carb?

I have two filters before the carb and yet the gunk had still found its way into the float bowl. I’m hoping this is my issue 🙏🤞🏻

I have just removed my tank due to the gunk and rust.

https://www.dropbox....d8623cveyt&dl=0

https://www.dropbox....rthdh4pnjg&dl=0

https://www.dropbox....nzb5l4zyte&dl=0

[gazza82]

What would be the best needle?
 I have just done a plug chop after a run and plugs are a bit on the rich side

What plugs are you using?