9K and she dies...

[packman85]

So I just got my carbs back from a buddy at work who was a motocycle Mech and he cleaned and rejetted them so there are 135 main jets fore and aft.  Put the carbs back on, took her for a spin.  Hesitated a bit, like it lurched at around 5 or 6k but it smoothed out.  Then the instant I hit 9 grand the bike shuts off.  Tach shuts off, spark dies, lights on the bars die.  Restart it, rev it up, same thing, the instant the needle hits 9 its sputters off... Is it a rev limmiter on the fritz, did I bump a wire harnes or something when I reinstalled the carbs?  Help...please.

[Brian Moffet]

rev limiter accidently plugged into the main relay???  Sounds like it is a Rev limiter problem.

Brian

[YellowJacket!]

The rev limiter is a common problem.  Most of us have clipped the rev limiter wire on our bikes and they run fine.  It is a black and yellow wire that leads to the TCI, but WAIT for someone else to confirm that before you clip it.  I did mine a while ago and my memory is cloudy about it and I don't have access to my bike to verify.

Hang in there.

David

[Night Vision]

try going here:

http://www.jetav8r.com/Vision/IgnitionFAQ.html

[YellowJacket!]

try going here:

http://www.jetav8r.com/Vision/IgnitionFAQ.html

Actually, heres the pic of the wire to cut...from the above link  <special thanks to leather for this resource!  ;D  >



David

[h2olawyer]

A better solution is to unscrew the wire from the tach & wrap it in electrical tape.  No cutting & everything is still in place without damaging the wiring harness.  (I like to keep changes & cuts in the wiring harness as minimal as possible.)  This method will make it easier to put everything back to original should you or a future owner wish to attempt a factory correct restoration.

H₂O

[Night Vision]

sounds like you have two separate issuse to address.... the cut out and the carb tuning / cleanliness

I was reading your old posts... before you said your tach didn't work... when did that change?

also, what carbs do you have? modified (vac flap) or unmodified?

have the plugs for the pilot screws been pulled so the carbs can be adjusted?

were the carbs dipped? or just spray cleaned? new parts/kit?

did you sync the carbs?

I do want to commend you on finding 9,0000 rpms though... I'm not sure how many Vnaries visit that special place or how often... I go there once in awhile just to keep her on her toes  ;) just got to give her a couple more miles after the valve adjustment, before I go back again.  ;D


oops.. sorry, I forgot... it will be a special place for you to go to soon

[h2olawyer]

Nine K RPM is nearing the top of the powerband.  NV is right - it IS a fun place to be & I find myself there on occasion.  However, watch out when you're playing around up there if your rev limiter is disabled.   ;D

H₂O

[Lucky]

I do want to commend you on finding 9,0000 rpms though... I'm not sure how many Vnaries visit that special place or how often... I go there once in awhile just to keep her on her toes  ;) just got to give her a couple more miles after the valve adjustment, before I go back again.  ;D

Puss... ;D ;D ;D

[packman85]

sounds like you have two separate issuse to address.... the cut out and the carb tuning / cleanliness

I was reading your old posts... before you said your tach didn't work... when did that change?

also, what carbs do you have? modified (vac flap) or unmodified?

have the plugs for the pilot screws been pulled so the carbs can be adjusted?

were the carbs dipped? or just spray cleaned? new parts/kit?

did you sync the carbs?

I do want to commend you on finding 9,0000 rpms though... I'm not sure how many Vnaries visit that special place or how often... I go there once in awhile just to keep her on her toes  ;) just got to give her a couple more miles after the valve adjustment, before I go back again.  ;D


oops.. sorry, I forgot... it will be a special place for you to go to soon

So, I've eliminated the Rev limiter as the problem.  I disconnected the wire.  When I fired her up, she would go up to and past 9k in nutral without shutting off, thought all was well Then I took her out  for a spin and found that when I would slowly bring the throttle up the bike would hesitate.  So I tried goosing the throttle quickly to see if it would smooth out, and because I like going faster.  And the bike would.. well it felt like it was choking then died completely.  So, is my vacum flapper not opporating? 

Ok, Heres the answers to your questions.
Tach, the needle was stuck, I just opened it up, moved the needle by hand put it back together and it worked fine.

2. Modified vacum flapper airbox.
3.The guy that cleaned the carbs said that he cleaned the pilot jets but it sounded like he didnt do a thourough carb cleaning, I know he didnt dip it.

4.Havent synced the carbs, but they seem to be pretty in sync, at least thats what he told me. 

The bike was running better before He cleaned it, it hesitated, but it didnt die and the hesitation wasnt as bad.  And thanks for the compliment, I like the 9k zone, it sure is zippy when you get her up there. 

[Coil Coyle]

[quote/]

2. Modified vacum flapper airbox.

[/quote]

What mod did you do to the Airbox Flap? If you did the 2 gram weight and the bigger main jets you may want to pull the weights from the flap before trying smaller jets.

$0.02
???
Coil

[Lucky]

and just to clarify:
if the bike has the airbox flapper & small disk filter on the ft carb, no modification is needed, other than pilot air jets changed to 135.  the unmodified carbsets don't have a vacuume line to the airbox, so 2 nickles epoxied to the flapper door are the fix.

--Lucky

[Night Vision]

do you have access to the pilot screws? are the seals/plugs pulled out?

until those carbs are spotless (that means disassembly and dipping), sync'd and adjusted.... you either won't be totally happy, or you won't know what you're missing between 3k and 8.99k  ;)

I did a total rebuild last year and thought my carbs were tweeked as good as it gets... nope, I cleaned them again this winter and found some tiny passages I missed the first time around (mainly the choke supply.. thanks CND Louie..) starts better now, runs better than ever  ;D

I have the modified air box, uni filter, running 130f 135r top jets and one nickle on the flapper.... joy!