TOPIC:

20 Pilot
115 Main

Thanks Patton, I kinda figured it was the same concept ( ) but now I almost HAVE to find a special tool to make that work. Pretty large diameter screws on the bottoms of those bowls...

six862m6 wrote: ...almost HAVE to find a special tool to make that work. Pretty large diameter screws on the bottoms of those bowls...

Thinking basically same as clear tube test on Mikuni smoothbores.
Without a side located drain screw, fuel is collected from drain hole at bottom of float bowl.

Some folks adapt a spare drain bolt by drilling and fitting a nipple to attach the clear tube.

I just use a cone shape rubber plug pressed into the drain, with a hole through the rubber plug, and the clear tube fitted snugly inside the rubber plug hole. Then hold the rubber plug in position during the measurement.

Others report using an inch of 3/8" fuel line (to fit snugly in the bowl drain threads), with a clear 1/4" hose inside the 3/8" hose.

Some minimal leakage won't affect the results, because fuel volume entering the bowl exceeds any leakage.

Regardless of particular method employed, clear tube test may be performed with carbs sitting level on the work bench or on a fully assembled motorcycle.

Good Fortune!

Where RS34 carb float height is significantly maladjusted, and desiring to get it set within the ballpark as prerequisite to the fuel level adjustment via clear tube method, here's the float height setting procedure.

And to again beat this very dead horse, float height is NOT assurance of correct fuel level.



Good Fortune!

six862m6 wrote: 20 Pilot
115 Main

i run 17.5p's @ 1/4 turn out, and 122.5mains in my kz1200

To test pilot try this method
Take a note pad with u.

cruse in 1st gear at 2000,3000,4000,5000 up to 1/2 throttle. hold each rpm for 15 seconds or until u are at a stable cruise (no accel , no deceleration). write down at what rpm's the bike stutters or fluctuates. adjust the pilot screws in or out (usually out) 1/8th and retest. continue this until it is smooth. if it is getting better as u adjust but cannot achieve a smooth cruse before u run out of adjustment , u must change pilots up or down 1 size and start over.
for RS carbs the pilot adjustment range is only from 1/8th to 1/2 turn out from seated max.
if u are lean, u can also try raising the needle, if u are lean in the middle anyways , this will help a bit. remember that all circuits DO have some overlap.

Main jet
hit the throttle from 3/4 to full hold for a sec then back out to 3/4 again. if it stumbles when u back out, try a bigger main until there is no change when u back out.
also, u can time your accelerate from say 40 mph to 60mph at wot. change mains until u achieve the shortest time.

for RS carbs the pilot adjustment range is only from 1/8th to 1/2 turn out from seated max.

Thanks for all the info, will be doing some adjusting and tweaking if and when the weather ever dries up again here. And REALLY?! (On the above?), the HS manual said between 1/4 and 3-1/2 turns out!!! So I started at 1 turn out thinking that was a decent starting point, sounds like not really at all though!

just go to the mikuni web site and download the RS manual. if u cant find it pm me and i'll email it to u.

I think I've got it, they call it "Series Application & Parts List" on the site's link for some reason, but it looks to have tuning info in it as well. Thanks!

You know, after taking a look at that info and specifically the carburetor applications section; it lists a set of RS36's as the correct set of carbs for my bike. Looking across the specs between the 34's and 36's on that sheet, the only difference is a 115 main vs a 130 main (for the KZ1000). So I would say I should probably get some 130s in my carbs, but does anyone think I may be beating a dead horse? That I really need to get myself a set of 36's and quit trying to tune a set of 34's that really aren't made for my bike to begin with? Thoughts?

36mm carbs will not fix the problem.

34's will work fine, one you get the jetting straightened out. You could jet a set of 26mm carbs to run that engine, if you where so inclined.

If it is falling on its face when you go WOT, sounds like going with a bigger main is a good direction.

130 sounds like a big jump though, I would start with 120's. 20's for pilot jets sound good.

Hopefully someone running rs34's on a 1075 will chime in with their jetting.

That would definitely be helpful if someone is running the same setup (1075 kit, very mild head work, stock cams, pods, header). It WAS falling on it's face before WOT, well before, until I moved the needle up a notch. Still has issues before WOT now, as mentioned before, but not near as bad. But raising the needle to the last (highest) position takes it in the wrong direction. SO, going to try some of the suggestions given here and up the main jets size.... suppose to quit raining here tomorrow and Thursday, just need to see if I have the right size jets in my stash.

tachrev wrote: 36mm carbs will not fix the problem.

34's will work fine, one you get the jetting straightened out. You could jet a set of 26mm carbs to run that engine, if you where so inclined.

If it is falling on its face when you go WOT, sounds like going with a bigger main is a good direction.

130 sounds like a big jump though, I would start with 120's. 20's for pilot jets sound good.

Hopefully someone running rs34's on a 1075 will chime in with their jetting.

I'll chime in then since I'm running a 1075,ported head with big valves, .410 cams, pods and a header with those carbs. My bike in northern Indiana likes 1/8 turn out, 20 pilots, needle on the 4th clip, and 125 mains. With that being said, it's not your bike and therefore your jetting will be slightly different depending on elevation, fuel quality, engine condition, and so on. As for putting 36's on, that's probably a bad idea since 34's will run up to a 1197 without problems. My bike would probably run better on the low end with smaller carbs say in the 29-31mm range, which is where it runs on the street, but on the top end move over 'cuz she's coming through.

EDIT: I could also stand to drop down to 122.5 mains but I've been to lazy to do it.