mg metro 1275, hif 44 carb cuts out at 4000 rpm

[bryshaw]

hello, ive got a problem with my mini. the 1275 mg metro engine has been fitted with an hif 44 carb, im on my second carb now but im starting to think there was nothing wrong with the first one. when i get to 4000 rpm the rev counter drops away to nothing and then the engine stalls. any ideas

[annodomini2]

Probably the electronic ignition module on the dizzy, common failure.

[bryshaw]

ok looks like this is right. however i put a mechanical dizzy on and melted the blue plastic on the contact breaker. now i assume this is because the dizzy is for a 9v ballast system and i have a 12v coil. the question is can i buy a ballast resistor to make it 9v or can i buy a module for the electronic dizzy.

[DollySprintV8]

Make sure you have wired the Coil correctly if using a normal dizzy and coil,
I.E.Positive and the Negative crossed over.

This will also cause the Plastic heal to melt on the contact breaker's.

[bryshaw]

ok, back to square 1. i now have a new carb, a new electronic dizzy and module and new spark plugs/leads and it still cuts out at 4000 rpm. if i gently get it above 4000 it runs fine but cuts out on the way back down the revs. any ideas?

[GreenV8S]

bryshaw said:

ok, back to square 1. i now have a new carb, a new electronic dizzy and module and new spark plugs/leads and it still cuts out at 4000 rpm. if i gently get it above 4000 it runs fine but cuts out on the way back down the revs. any ideas?

Tacho still dropping out? If so that indicates it's still an ignition problem on the LT side.

[bmt216a]

Have you had a needle made for the carb, very important if running an mg metro in a mini. Once I had mine on the rolling road and tuned it was great.

[skyedriver]

Funnily enough,I bought a replacement needle for my HIF44 as the MG Metro engine had been tweeked a bit, it ran extremely rich and I went back to the standard needle.
ps still running in and it hasn't been up to 4000rpm yet!!

[DollySprintV8]

Going back to basic's what have/did you set the timing to.

[tim-d]

Just a thought but what fuel pump are you using? If you have a dying mechanical pump it could cause similar symptoms when the demand for fuel exceeds available supply.......????????

[hengti]

bmt216a said:

Have you had a needle made for the carb, very important if running an mg metro in a mini. Once I had mine on the rolling road and tuned it was great.

seconded

are you running a non std air filter?
that'll make it run even leaner

if it's been tinkered with at all (esp. air filter), the only way of getting the fuelling sorted reliably is on the rr - a decent operator will be able to make you a needle to suit

[bryshaw]

hello again i may be a little slow on the uptake here but was i supposed to let the needle run in? oh dear, yes definately oh dear

[bryshaw]

ive not had a needle made, i have a kn filter on so i bought the bbw needle from mini spares and its a bit crazy on the throttle now and still cuts out also i have een trying to adjust the float level. any ideas on how to do this properly and where to take measurments?

[hengti]

no need to run needles in

it's been a while since I've tinkered with minis, although I do remember fitting one with a K&N and weakening the fuelling to such an extent that it wouldn't pull at all beyond certain rpms

don't remember it cutting out though

carb icing is another possibility. is it particularly cold where you are at the mo? have you got a heated inlet mani fitted?

might be time to ring an expert mate - have a look in the back of the mags for the usual suspects

[bryshaw]

problem solved, an intermittant fault with the starter solenoid, under my nose all along.

[annodomini2]

Good to hear!