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Idle problems
robbydee - 6/7/04 at 07:11 PM

Having problems getting 2.0 pinto on twin 40's to idle have a good spark but can take off the leads to plugs 3 and 4 with no affect on the idle... running is fine though... have followed various setting sheets etc but no avail help!!!!

Jon Ison - 6/7/04 at 07:13 PM

have you set the butterflys up ? is the carb feeding 3&4 closing all the way ???


Get it on a rolling road......only true way to set any engine up.

robbydee - 6/7/04 at 07:16 PM

due to go to the rolling road on the 25th july just a pig till then wanted to get somthing like it should be and not made to look a @*@* !!

ady8077 - 6/7/04 at 07:26 PM

Hi

Have you balanced the carbs? sounds like 3 & 4 not open enough/open too much

Also what idle jets are you using? Mine wouldn't idle very well and had to change them to 55F9's

Also are the pump jets ok? one of mine got blocked and that affected idle at start up

Adrian

Jon Ison - 6/7/04 at 08:09 PM

why would you look like a @!@! taking a rough running engine to a rolling road ???

people spend hundreds on engines then lose loads a performance by not having it set up properly, as stated earlier it sounds very much like you may have 4got to set up (balance) the butterflys, once the throttle is opened this symtom would go away,

another thing people miss is are they opening all the way, ive seen £100's spent on big carbs then the whole lot wasted by not checking if they are opening all the way on full throttle........


if you tried the "bit o spit" on 3&4 exhaust manifold, best tried on an engine b4 you rev it........... ie only idle speeds warming the exhaust.

robbydee - 6/7/04 at 08:24 PM

here goes...
choke 34
main 135
emulsion f16
corrector 180
idle 45f9
pump jet 40

any obvious problems here?

Jon Ison - 6/7/04 at 08:28 PM

all IMHO but all i ever do is get them running summat like then go play on the rollers, without it you'l never know......

ive seen the sweetest sounding running engines that you could'nt fault by ear or feel go on the rollers and still come of with impressive gains

Dave Ashurst - 6/7/04 at 08:40 PM

quote:

any obvious problems here?




The obvious problem is that one carb seems to work and the other doesn't.

If the jetting is the same on them both then the jetting doesn't sound like the problem, does it?

I'd recommend taking Jon and ady1077's advice. Perhaps you could borrow a flow meter to try balancing the carbs in the meantime?

robbydee - 6/7/04 at 08:45 PM

brain wave going to swap all the jets over form one carb to the other and see what the result.

robbydee - 6/7/04 at 09:35 PM

how you alter the balance>?

britishtrident - 6/7/04 at 09:49 PM

quote:
Originally posted by robbydee
how you alter the balance>?


Very basic the little screw between the carb spindles BUT when setting carbs check everything is as it should be first first only then do the adjustments.
Suspect you really should get yourself a book on setting carbs first before you start twiddling, setting up multiple carbs to give a clean idle is quite a skill, but Webers are easier to balance than clapped out twin SUs.

robbydee - 6/7/04 at 09:58 PM

just curious being a gas engineer I use a manometer "U" gauge so going to rig up to see whats going on..

jacko - 7/7/04 at 07:48 PM

British Trident
Hi-all: Easier to balance than clapped out twin su's.
How much does it cost for twin webbers? Ive fitted twin 1.3/4 su on a 2.1 pinto and it cost £24 for the carbs and £46 for new needles and jets etc. and it runs very well. Jacko. ps Please look back on previous posts under SU carb's.

gjn200 - 7/7/04 at 10:14 PM

quote:
Originally posted by jacko
British Trident
Hi-all: Easier to balance than clapped out twin su's.
How much does it cost for twin webbers? Ive fitted twin 1.3/4 su on a 2.1 pinto and it cost £24 for the carbs and £46 for new needles and jets etc. and it runs very well. Jacko. ps Please look back on previous posts under SU carb's.


This sounds interesting, wheres/whats the manifold from?

NS Dev - 7/7/04 at 11:02 PM

If you can get a manifold then there's nowt wrong with SU's, especially the later ones, for road use. You may sacrifice some power over Webers but the fuel economy will be miles better and so will the tractability. Fuel injection better still but costs a lot more!!!

jacko - 8/7/04 at 06:47 PM

Hi Gin 200, I made my own manifold. The fuel consumption is about 40 miles per gallon and the performance is about the same as twin 40 webbers. I dont know bhp figs. yet because I have not been on a rolling road yet. I am very happy with the set up. I would just like to thank Mark a mate of mine for getting me to go ahead with the set up. Jacko.

gjn200 - 9/7/04 at 07:07 PM

Any chance of a piccy?