dmrider_10
|
posted on 6/10/14 at 01:51 PM |
|
|
People running bike carbs, whats your throttle tip in like?
2.0l I4 from an RS2000 with ZX6R bike carbs
I know my AFRs are all good etc and the car pulls well. But If I'm going from the overrun back onto the throttle theres a slight hesitation and
its very slightly jerky unless you apply the throttle VERY gently. This is more of a problem when driving slowly around town than when giving it some.
On a mappable injection car, this would be cured by adjusting acceleration enrichment, but on carbs????
|
|
|
whitestu
|
posted on 6/10/14 at 02:27 PM |
|
|
I can't say I have the same problem on mine with ZX6 Carbs.
Is it actually a problem wiht the carbs or could it be the throttle linkage / pedal travel being too sensitive?
Stu
[Edited on 6/10/14 by whitestu]
|
|
MikeRJ
|
posted on 6/10/14 at 02:44 PM |
|
|
Sounds like your pilot jets may be a little on the small side.
|
|
dmrider_10
|
posted on 6/10/14 at 02:46 PM |
|
|
No it's deo not a linkage/cable issue or anything. It's a throttle "tip in" issue. I'm wondering if it's the ratio
of pedal travel and throttle opening? As in it's too aggressive?
|
|
whitestu
|
posted on 6/10/14 at 02:49 PM |
|
|
quote:
No it's deo not a linkage/cable issue or anything. It's a throttle "tip in" issue. I'm wondering if it's the ratio
of pedal travel and throttle opening? As in it's too aggressive?
Sorry - that's what I meant by the linkage / pedal.
Stu
|
|
dmrider_10
|
posted on 6/10/14 at 02:53 PM |
|
|
Ah right I thought you meant sticking etc.
In that case, how far into your pedal travel is your throttle fully open? Have you kept the standard cable "cam" on the carbs?
|
|
19sac65
|
posted on 6/10/14 at 02:58 PM |
|
|
Ive heard some suffering this because the slides are opening too wide too quickly due to a car engine creating way more vac than a bike does
The fix is to close up the hole (s) in the diaphragm
Happens occasionaly on mine if ime aggresive with it at low rpm
|
|
whitestu
|
posted on 6/10/14 at 03:39 PM |
|
|
Yes, the cam on the carbs is standard.
I moved the point where the pedal connects to the cable closer to the pivot though to make it a bit less sensitive.
Stu
|
|
BaileyPerformance
|
posted on 6/10/14 at 06:14 PM |
|
|
quote: Originally posted by 19sac65
Ive heard some suffering this because the slides are opening too wide too quickly due to a car engine creating way more vac than a bike does
The fix is to close up the hole (s) in the diaphragm
Happens occasionaly on mine if ime aggresive with it at low rpm
Yes, we have seen this issue and a way around it is as 19sac65 suggests
Also, the springs can be changed for some heaver versions slowing the the response of the slides, a fast acting slide causes a lean mixture when the
throttle is snapped open, is its damped by a heavy spring or close up the hole it enriches the mixture. If it was an SU you would put heaver oil in
the dashpot to correct the issue
Regarding jetting, what AFR to you see at very light throttle, light load?
www.facebook.com/baileyperformance
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
|
sjmatthews
|
posted on 6/10/14 at 09:17 PM |
|
|
I had a hesitation when going back onto throttle or when using very light throttle. The occasional spit back confirmed a lean spot which I cured by
fitting a couple of washers under my needles. See here...
Needles...
I'll be in the garage dear!
|
|
coozer
|
posted on 7/10/14 at 11:31 AM |
|
|
I moved the cable further away from the pivot point on the pedal and that smoothed out the action but made the travel a lot longer. It was jerky with
the short throw on the throttle.
1972 V8 Jago
1980 Z750
|
|
monsterob
|
posted on 7/10/14 at 11:42 AM |
|
|
not had mine driving :-(
|
|
Jenko
|
posted on 8/10/14 at 02:47 PM |
|
|
I think also this can also be caused by the AFR being too lean between fully closed throttle and very light throttle load.
MY BLOG - http://westfieldv8.blogspot.co.uk/
|
|