MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - SU HS2 Carb tuning failure

1974 MG midget 1200cc
CARB TUNING HELP!
Reasonably broke the connecter that opens my front carb. I bought the part and a carb rebuild kit because i had the carbs off. Fixed and rebuilt carbs properly. Reinstalled on car and attempted to tune... Idling is great and i can get it to pass the piston lifting test, but when i finish everything and give it gas it wont rev higher than 2500RPM and it backfires some times with smoke sometimes with out. Ill continue to adjust with no avail.

After starting over 3 times and this happening every time i finally took the carbs back off and replaced the new jet with the old, retuned twice and still the same problem. I finally got frustrated. I have no clue what to do now?

I pulled the spark plugs at the end and they were very black. I replaced them 2 months ago so i don't think there bad, my very last attempt at fixing the problem is to replace them unless anyone has any other suggestions?
jh hall

Check your float chamber valve clearances if you have replaced them as part of the kit.
Brad (Sprite IV 1380)


JH - suggest you look in the archive files and search for 'tuning'.

Gavin Rowles

Hmmm,

the black plugs would suggest to rich.

what springs and needles are you using...Is the needle Not hanging up in the jet.

did you spray the carb down with WD40 to check for air leaks...yeah that would be lean

Id also look at the linkage isnt hanging or binding...vary common issue

But like Brad....It well could be a float level issue.

what about blockage in the vents...are the jets new, if not look for blockage in the jet tubes from the float bowl to the needle

dunb question but do you have oil in the dash pots...if its out in the cold you may want to try 10W40 oil instead of 20W50 in the dash pots I know that always works better for me in the dead of cold


there some ideas...you will get more in a bit.

Prop
Prop

This thread was discussed on 12/02/2010

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.