23 replies to this topic

[Steve-O 2014]

When on a run we find Bob runs better with the choke set to 2 pegs out (the choke keeps popping back in by itself so we use pegs). With the choke in he struggles to get up hills and struggles to hit 50mph. With choke out 2 pegs he seems to go well.

 

The engine is a freshly rebuilt 1000cc high compression engine that the previous owner had fitted and it has I think a metro carb fitted to it (i think thats what the previous owner said)

 

Does it sound like with the choke fully in the car isnt getting enough fuel?

 

Any help would be great

 

Thanks

[Carlos W]

Definitely sounds like it's running lean! 

 

It might be worth getting it set up on a rolling road!

[Tamworthbay]

Have you whipped the plugs out and had a look? As Carlos says, sounds like its running lean.

[L400RAS]

Either tune up the carb or look for possible air leaks.

[thegreenhornet]

I'd try not to drive it too much until you can get it sorted if it's running that lean! Don't want to melt something. Like a piston :|

Try richening the carb a bit until you find the highest idle speed. At least then it should be roughly right, if that's the problem.

[Kieranlee999]

might want to get your engine tuned :) 

[minimender]

+1 for running weak, could be pipe breather off or perished, if not richen up mixture.

 

As suggested, turn fuel screw in to richen,  engine idle will speed up, one turn at a time blipping the throttle in between until revs start to drop off again. Then turn back half a turn and see how it goes.

Count total turns so you can put it back if not happy.....but you should be ok.

[coopdog]

Get it on a RR mate

[minimender]

Get it on a RR mate

 

Don't know about you but my experience with rolling roads is that they tend to tune it on the weak side and a little too retarded on the ignition, maybe its the operators that are not the best, they seem to concentrate too much on emissions these days in my oipinion  

[Kieranlee999]

 

Get it on a RR mate

 

Don't know about you but my experience with rolling roads is that they tend to tune it on the weak side and a little too retarded on the ignition, maybe its the operators that are not the best, they seem to concentrate too much on emissions these days in my oipinion  

 

i just got a bloke out with a meter of some sorts to tune it so it didn't run rich or lean  

[Steve-O 2014]

Thanks, I will also check the timing, I have a basic timing light / gun, is this any good to use on the mini? 

[minimender]

Thanks, I will also check the timing, I have a basic timing light / gun, is this any good to use on the mini? 

Yes, mark timing marks with tipex to make it easy

[Steve-O 2014]

thanks, what should it be set to as standard? 

[minimender]

thanks, what should it be set to as standard? 

Standard will be slightly out due to wear in timing gear, cam drive and dizzy, and it depends on spec.

[minimender]

thanks, what should it be set to as standard? 

You can find out by looking on dizzy base plate for number stamped in it.

If its 15 then you only need about 2 degrees static advance

If its 10 then you will need about 10 degrees static advance.

 

The 10  or 15 or whatever should be doubled and should come out at 30 ish, if not add the required amount of static to make up to 30 ish..

 

eg. 10 x 2 = 20 + 10 (static) = 30 degrees total advance with engine running about 4000rpm (Vac pipe off)

.......13 x 2 = 26 + 4 (static) =30........................

.......15 x 2 = 30 + 0 (static) = 30.......................

 

some early 850 engines needed more advance so had 18 deg dizzys (36 deg total)

 

Some engines only need 30 total advance some need 35 depends on spec

 

someone will come along with factory settings I'm sure but be aware that you need to account for wear

 

30 deg is an approximate figure, could be 28 could be 33 depends on engine

Edited by minimender, 02 February 2014 - 08:43 PM.