when i start my 1977 mgb it ticks over ok then the revs start to climb the pistons in the carbs lift themselves they have the right amount of oil and grade

30

Asked by Jun 17, 2013 at 01:58 PM about the 1977 MG MGB Roadster

Question type: Maintenance & Repair

when i start my mgb it ticks over ok but after a min the revs start to climb if i unscrew the carb dip stick  and lift it and replace it the revs die back down again for a few mins then climb again the pistons are lifting by themselves

5 Answers

"carb dip stick"...kinda lost me on that one, I know these have special vacuum controls goosing the the throttle open smoothly, are these the things that you are changing? do not understand~

30

the dip stick in the top of the carb with black top well kind of dipstick, i just bought the car it was running rough i got it to run smooth but now the revs climb by themselves the pistons in the carbs are lifting and bringing the revs up,

2 out of 2 people think this is helpful.
30

its called the dampening valve it has a black plastic opr brass top if i unscrew this and lift it slowly then push it back in the revs drop for a few mins then pick up again

1 out of 1 people think this is helpful.

want to help, but this is uncharted territory for the judge~

4,755

What sort of carbs are on your car? SU's or Zenith Stromberg? A bit more info would go a long way. Also these constant vacuum carburettors are quite sensitive to other faults, things like poor compression or offset timing can have a huge effect on idle speed, so I normally start with checking those before even looking at the carbs. From there on I check oil level in the dashpot (where you took out the little dip stick, it should be filled pretty much to the brim with SAE 20 oil). Then a quick look at the throttle spindles to make sure there's no free play or vacuum leaks and from there on I normally go for a carb tune (get out the synchroniser and tachometer and get it set up right).

1 out of 1 people think this is helpful.

Your Answer

Add photo

Related Questions

  • My motor is ticking more when I give it gas. 43 answers

    This started a couple of weeks ago and the ticking did not seam so bad it is now getting louder specially when I give it gas. It is sounds like the motor and I can't tell which side. I am a woman and ...

    1999 Ford Mustang

    -

    Maintenance & Repair

  • Would you recommend using Marvel Mystery Oil for a slight ticking noise? 2 answers

    Just recently bought used with 92,000 miles on it. Appears to have been well taken care of and runs great. However, lately it has been making a slight ticking sound when first started or after sit...

    2006 Mazda MAZDA6 s Sport 4dr Hatchback

    -

    Maintenance & Repair

  • what is causing the ticking? 2 answers

    it only happens when i accelrate. as the rpms go up the ticking seems to follow it. i can hear it clear as day in the cabin of the truck. not sure if it can be heard on the outside.

    1995 Chevrolet Tahoe 4 Dr LT 4WD SUV

    -

    Maintenance & Repair

  • oil grade 4 answers

    I have just recently purchased and have no owners manual. I am wondering what grade of oil to use on a 3.0l 24v

    1990 Mercedes-Benz 300-Class 4 Dr 300E Sedan

    -

    Maintenance & Repair

  • what grade oil 1 answer

    what oil grade do i use

    1992 Volkswagen Golf 4 Dr GL Hatchback

    -

    General

MGB Roadster

Looking for a Used MGB Roadster in your area?

CarGurus has 9 nationwide MGB Roadster listings and the tools to find you a great deal.

ZIP:

Search MG MGB Roadster Questions

MG MGB Roadster Experts

#1 oldtimer37
oldtimer37
Reputation 40
#1 Curtis Wright
Curtis Wright
Reputation 40
#3 Lars Cats
Lars Cats
Reputation 30
View All

Related Models For Sale

Used MG MGB
75 listings
Used Mercedes-Benz SL-Class
112 Great Deals out of 3,373 listings starting at $1,500