Does this sound like an air-leak to you?

Post by **Neosophist** » Fri Sep 19, 2008 10:10 pm

Right, stripped down and cleaned the 35's carbs, checked the float heights, worked on them all one at a time to avoid messing any jets up. Float height's are all fine, jets are standard and after a clean and blow through with compressed air the horrible flat-spot between 4-7k has gone.

After putting the carbs back on the bike I balanced them using the carbtune II (morgan) which most of your are familiar with.

The only problem is the idle doesn't seem to want to stay where I put it, say if I set it to 1400rpm when the engines warm, i'll drive a bit, pull up to some traffic lights and the idle willl be really low, say 6-700rpm, so i'll adjust it up a little and next time I stop the idle will be like 2000rpm.

I was thinking the carbs might not be sealed 100% on the rubbers, anyone agree with me, otherwise when i get them off again i'll re-strip and clean them.

Post by **wullvfr** » Fri Sep 19, 2008 10:34 pm

how was the idle before you carried out the work?could be not sealed right on the rubbers but in my opinion it would run a little crap whilst riding but its maybe worth while taking them back off and back on just to rule it out....what about the valve clearances,when was it last done? :D

Post by **Neosophist** » Fri Sep 19, 2008 11:06 pm

Idle was rock-steady before taking the carbs off, forgot to mention that! Checked the valve clearances and there all ok.

Dont' really wanna be dismantling the carbs again if it sounds like an air-leak. Bike runs fine other than the idle not being right.

Post by **wullvfr** » Fri Sep 19, 2008 11:23 pm

its a strange one this one,i would maybe check the vacuum hose just to be sure and take the carbs off and then straight back on just making sure they are on the rubbers good and proper........making sure the clamps are nice and tight!!!!!!!
if you've set the idle correct when its heated up.
its strange how its idles low and then the nxt it will be high.....

randallbass · Post by **randallbass** » Sun Sep 21, 2008 5:19 am

is the spring still on your idle adjustment?
if your idle adjustment screw isnt moving, make shore carbs are seated correctly, and hoses to fuel tap are ok, air box is clear n filters ok.
if these all check ok id check the mixture screws.
try holding you hand on the exhaust when the revs are higher to load up the engine, watch the revs drop then take your hand off the exhaust, or put bike in gear and let clutch out with front brake on and no throttle just to lead engine and see if revs drop when your hand is removed from the exhaust or when you pull the clutch back in.
if the revs do drop thats a sign of poorly seating carbs or mixture screws are not right, did you adjust them at all?
cheers Tim

russ tyson · Post by **russ tyson** » Sun Sep 21, 2008 11:59 am

an air leak normally shows on tickover because when you blip the throttle it takes a while to get back to the same idle speed. Russ

Post by **Neosophist** » Sun Sep 21, 2008 4:51 pm

got the carbs in complete, can't take them apart anymore pieces now.

Never noticed before but it has the rounded sliders in it with the two air holes (identical to the ones in my 24) and is running 115 jets all round, different number of holes in the emulsion tubes though.

Theres some faded pen on the top of one of the carbs that say it was tuned in 98 in Japan. Although the pilot screws varied between 3 and 6 turns out :S

Carb -> Manifold rubbers dont' look too bad tbh, so when I get them back together i'll make sure they are properly seated and see how it runs. I think i'll need more equipment than I have here to get it set up properly.

Best place to get jets from btw?

Post by **Neosophist** » Sun Sep 21, 2008 7:17 pm

ok carbs are deffiantly seated properly now.

The idle speed is quite wild, jumping from 1300 - 1450 and back again. I think im gonna have to take it to a bike shop, carbs really arn't my thing

Post by **CMSMJ1** » Mon Sep 22, 2008 11:19 am

Neosophist wrote:
Never noticed before but it has the rounded sliders in it with the two air holes (identical to the ones in my 24) and is running 115 jets all round, different number of holes in the emulsion tubes though.

Are you sure theya re '35 carbs?

35 carbs are semi flat slide and you would not be able to fit the rounded slides out of an NC24/30.

Post by **Neosophist** » Mon Sep 22, 2008 12:12 pm

I think they are NC30 carbs

I'm in the process of putting it back together as we speak, see if it's any better. If not i'll source some 35 carbs.

Does this sound like an air-leak to you?

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