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View Full Version : C14SE & twin 40 weber combo...



Mk1'SR'Dan
28-06-10, 08:15 AM
hello folks, got my nova running properly now, just had to re-jet my carbs to get it running a bit richer in the higher RPM, ive just changed the set up slightly (was 115 mains on 200 airs, changed to 120 mains and 180 airs on 30mm main venturi) as it wasnt jetted right by the bloke i bought them off, after re-jetting it still does seem a little bit lean in the high revs, ive now got 30mm main venturi, 120 mains, 180 airs, F11 emulsions, 45 F4 idles, and 40 pump jets... i know ive got the main circuit right now, but its the idles that are now making me think its them that need changing as well... anyone got any ideas? cheers peeps...

PaulW
28-06-10, 01:31 PM
My engine is a fairly heavily modified 1396cc 8v, and these were the jets i used in my sport carbs. No harm in giving them a go.

32mm chokes, 140 air collectors, F16 emulsion tubes, 130 main jets, 45F6 idle jets, 40 pump jets

The first page of this thread has the spec of the engine.
http://www.pngclub.com/forum/showthread.php?t=133351

I hope you sort things out and get it running the way you want.

Mk1'SR'Dan
28-06-10, 08:13 PM
cheers for the advice mate, although, ive got a very reputable weber book and it says you should times the size of the main venturi by 4, the add 60 for the air corrections, ur setup does seem a little odd but that i guess, is the way of the weber, idles to be changed next methinks, and maybe even changing to F16 emulsions, its running nicely, just seems to hunt a little bit when its over 4500rpm... backfires like a beaut too... drops from about 4500rpm and finishes with a nice crisp pop...

PaulW
03-07-10, 04:20 PM
Edit nevermind sorry misread post, you just said it runs nicely up to 4500, an airleak would affect idle. Please ignore this post sorry.

Mk1'SR'Dan
25-07-10, 12:47 AM
perhaps i need to tighten the misabs up a bit more, i cant hear any air leaks but the doesnt mean there isnt one, i actually got it off the lawn and attempted to drive it today, its fine up to around 3k, then it just totally peters off, and nigh on stalls, i havnt had the carbs balanced yet because ive just about rebuilt it, its not a daily driver and it barely moves, i just want to get it jetted right myself so the dyno place doesnt try and bugger me sideways for new jets, i think the problem lies with the idles and the emulsions myself, i need bigger idles and F16 emulsions, maybe even smaller airs, running 180s at the moment... it must be so lean in comparison to yours Paul... i think i need to bite the bullet and buy a syncrometer... and the elbow, for ANOTHER 30 quid...!!

Mk1'SR'Dan
25-07-10, 01:00 AM
yeah... just checked out my jet supplier and done a bit of research, and, the F11 jets ive got in my carbs are best suited to applications using airs of 2.00mm and over... so they're definitely getting changed... and up to 45F6 idles... and maybe even down to 160 airs? or maybe upping the size of the mains could make a drastic difference...