mikuni rs 36 s

does anybody know what needles i should use i have 130 mains and 17.5 pilots p-4 needle jet and the needles i have now are 9dzh5 all the specs i found says the needle should be 9dzh1 will the needle make much of a difference???? i have the a/pump back off and i have no throttle responce i took the plugs out there black the motor is stock all but pods and 4into one

What bike are these carbs on? I can't see the bike very well in the avatar and you don't have it listed in your signature line.

Later, Doug

It is hard to say without knowing about your bike, but I have recently purchased rs carbs, and was having similar problems. I found going to 15 idle jets cured a lot of the problems.I have a pretty open exhaust though.
Jet needles are 9dzh1 set on 4th clip position. Hope this helps

stock 83 gpz 1100 just pods and 4 into one vance and hines maga fone

boo9_23_78 wrote:

does anybody know what needles i should use i have 130 mains and 17.5 pilots p-4 needle jet and the needles i have now are 9dzh5 all the specs i found says the needle should be 9dzh1 will the needle make much of a difference???? i have the a/pump back off and i have no throttle responce i took the plugs out there black the motor is stock all but pods and 4into one

As known, black plug color may result from several non-carb conditions, such as ignition and/or compression issues. But agree the richer 9dzh5 jet needle (compared to leaner 9dzh1) is a suspect regarding plug color and poor throttle response.

Might help to re-clip the existing 9dzh5 jet needles to a higher notch (closer to the blunt top end of the needle) so the needles sit lower into the jets while running, which would affect mostly the mixture at 1/4 to 3/4 throttle openings.

May also want to check the float bowl fuel level to assure it's not too high causing an over-rich mixture. And assure that pilot fuel screws are properly adjusted. (And that choke is fully off )

Could be mistaken, but the jet sizes seem okay.

Good luck!

i tried to reclip from the top down still the same the compression is 180psi its a 1089 cc i was told the carbs might be to big for my motor my compression is a bit low i was told my compression should be 190psi or higher to use the rs36s the ignition system is stock the air fuel screws are 1/4 to 3/8s turns out

Post edited by: boo9_23_78, at: 2007/11/24 11:36

Post edited by: boo9_23_78, at: 2007/11/24 11:40

Post edited by: boo9_23_78, at: 2007/11/24 18:23

boo9_23_78 wrote:

i tried to reclip from the top down still the same the compression is 180psi its a 1089 cc i was told the carbs might be to big for my motor my compression is a bit low i was told my compression should be 190psi or higher to use the rs36s the ignition system is stock the air fuel screws are 1/4 to 3/8s turns out....

tried to reclip from the top down still the same -- Re-clipping closer to the pointed end of needle jet raises the needle which enrichens the mixture which blackens the plugs even worse.

the compression is 180psi.... -- Seems high enough to me, but am unaware of specs per FSM.

its a 1089 cc i was told the carbs might be to big for my motor -- First time hearing this (doesn't mean it isn't so, but seem to recall other users being well satisfied with the RS36's).

ignition system is stock -- As earlier noted, black plug color may result from several non-carb conditions, such as ignition and/or compression issues, both of which should be tested and assured to specs before addressing the carbs.

Perhaps someone having more RS36 carb experience will offer better suggestions.

EDIT: I did a forum search and see where the smaller RS34s are sometimes recommended for motors closer to stock configuration. To see these posts, type RS36 in the search forum box and press enter.

Good Luck!

Post edited by: Patton, at: 2007/11/24 19:48

Post edited by: Patton, at: 2007/11/24 20:06

well i put new rings and had the head cleaned and rebuilt with all stock parts the only thing that comes to mind is valve clearance i havent check it yet i did a comperssion test 180 psi across the board and maybe the ignition system has any one done this should i change the ignition system ???? ill have to check the valves thanks for the imfo should change the needles

boo9_23_78 wrote:

well i put new rings and had the head cleaned and rebuilt with all stock parts the only thing that comes to mind is valve clearance i havent check it yet i did a comperssion test 180 psi across the board and maybe the ignition system has any one done this should i change the ignition system ???? ill have to check the valves thanks for the imfo should change the needles

Compression seems fine, and am guessing valve clearances were adjusted incident to head rebuild (but won't hurt to re-check them).

Ignition system may also be okay. Would check for good fat blue spark at plug tips. If still using original oem ignition components, might want to measure ohms between posts on coil for primary windings and between spark plug caps for secondary windings. If both coil primary windings measure the same and both coil secondary windings measure the same, the coils are likely okay.

Would also assure full battery voltage is reaching coils. And that battery is in good condition, and reading about 12.5 volts across terminals at idle rpm and about 14.5 volts at 3000 rpm, and wire from negative battery terminal is well connected to ground.

Would also assure that carb pilot circuits are perfectly clean (air passages, fuel passages, pilot jets, and pilot air jets). That the float needle/seat interfaces are not leaking. And that the pod filters are allowing ample air intake.

Btw, is 4/1 exhaust baffled or open?

If not already at hand, here's a link to some detailed information and parts diagrams of the Mikuni RS carb series. Be patient when downloading.

RS Carbs

the carbs are clean and iam going too check for good spark what would you do for ignition mods

boo9_23_78 wrote:

the carbs are clean and iam going too check for good spark what would you do for ignition mods

If the factory equipped 1983 GPZ1100 ignition components (coils and igniter) are functioning properly, I wouldn't expect a dramatic improvement from any particular after-market modification. But am out of my league here and could easily be wrong. Believe some members are using Dyna 2000 ignition on GPZ1100 with good results (ignition housing with seal from KZ1000J motor )

Btw, for better help with ignition mods, might consider starting a new thread topic in the electrical forum. Just a suggestion.