carb set up advise please ,

[motostorm]

hi all , i just want to say first , i know members here have put a lot of effort into posting much info already ,

i have searched already and found great info, and links (on and offsite ) in this thread , : http://vtr1000.org/phpBB3/viewtopic.php?f=31&t=14214

i dont want to choke that thread up with loads of posts as its staying fairly specific

so any informed help with a couple of questions would be appreciated (especially if youve posted already )

bike set up , theres a dynojet sticker on it , maybe it is , maybe it isint , standard airbox , standard filter , snorkel fitted , micron carbon cans , motors good !

i had planned to do the tps mod , but wanted to run the bike on the dyno first to see whats going on with the fuelling , hopefully do the lot together ,

the bike is fuelling fine on the main jet , the needle is slightly lean

but the idle circuit is very lean , this explains 1/8 1/4 throttle ''stall''/ ''delay'' i am having .

1. so...... my bikes a 97 , and it seems first models were fitted with 45 pilots and later models 48 , im guessing that i will get a better base to work from replacing the pilots to 48;s rather than trying to ''dial out'' the leaness on the fuel screw (always called the air mix screw)

2. anyone have an idea where changing the pilots would leave me in relation to the fuel screw setting , e.g. at that point would i be likely to be rich or lean?

3. i know the fuel screw settings are 3 out f , and 2 3/4 out r ,but is that for both set ups ,, 45 pilot and 48 pilot equipped machines ?

any input anyone?? mucho appreciated

[Phimosis]

Cheese, a good cheese and port, then forget.

[motostorm]

Cheese, a good cheese and port, then forget.

closest i have is hulahoops (in date!!) and cheap beer ,

[Kev L]

You Sir are a classy dude and no mistake. In date you say, pure class.

[VTRDark]

1st Why not have a look inside the carbs so you know exactly what sort of set up it has. whether it has a dynojet kit in there or a mix. You just don't know for sure otherwise. Check what size and brand mains you have, are the needles adjustable, how many holes in the slide and what size pilot are there too.

2nd If they are 45's and you put 48's in then it will richen it up. So if the needles are a tad on the lean side increasing the pilot will help there without adjusting the needle. It will also help the low end even more so if that is lean. Have you done a choke test to determine if it is defiantly lean. By pulling the choke it increases the fuel. Don't pull it all the the way out as this will just richen it too much and flood it, so just pull it out a tad, maybe an 1/8 of the way, and see if this improves things.

3rd What you have there is the standard set up for 45's according to the workshop manual and is just within it's limits of 3 turns. Anymore than that then you should go up a size on the pilots. This does not mean you have 45's for sure as they might be more turns out to compensate for something else like an overly lean needle. What's the bike idle like, does the rev needle fluctuate. Blip test will tell you if the mixture/pilot screw is set right.

With larger pilots it will require less turns out. Approximately 2 1/4 rear and 2.5 front. Basically the larger the pilot the less turns out required and the smaller the pilot is more turns out.

If it was me I would remove the carbs give them a clean and at the same time see exactly what's in there. Adjust the TPS, re-balance carbs and go from there. Obliviously a dyno will tell exactly what's going on with the fuelling. And for lunch break cheese and wine

(:-})

[motostorm]

hi carl , the plan is to pull off the carbs next couple of days , im just trying to get an idea where ill be in relation to the different pilots ,
i knew something wasent exactly right with the fuelling just on the very start of the throttle at low revs and a quick jolt open at tickover ,
thats why i did the dyno run yesterday which revealed it running very lean on the idle circuit , and only very slightly lean on the needle side dyno man suggested move one clip position richer on the needle , its putting out 95 hp (accurate road racers dyno) and thats fine , im not chasing hp just as good fuelling as i can get ,just nice characteristics getting on and metering the throttle !

re; blip test revs drop correctly no ''settling ,, just nice , tick over is sweet ,

ill report back , on what i find , but i doubt the screws have been adjusted on my bike ! , from the reading i done on the other thread my guess at the mo is , i will find the 45's

plan will be tps , check pilots / fuel screw position / after that balance , and possibly stick coil convertion, i have set there (but im sceptical about any results there ,,,

thats the plan anyways

i have the fancy cheese for lunch , already sliced and each slice is indiviually wrapped , luxury !!!!!!!!!!

[VTRDark]

OK didn't realise you have done a dyno run. If the dyno guy says to richen the needle a clip position then that's what you should go with. After all the dyno tech can see the A/F reading throughout the whole range so knows where adjustment is required. Did they give you the printout, it would be interesting to see the readout.

The stick coils do work well. A noticeable difference in power and less cranking to start the bike. The power increase is more than likely because your abandoning the HT leads which are more than likely deteriorated to begin with anyway. I'm not sure if just replacing the HT leads has the same effect, but considering the HT leads are fixed to the coils and they are not easy to change on their own the stick coils are are good move.

(:-})

[popkat]

The needle on a cv carb effects wide open throttle in the midrange, you can get away with it being slightly lean for better pickup and response.

[motostorm]

right ,

carbs off and indeed 45 pilots fitted , just changed to 48s , im wondering now should i leave the airsrew/fuel screw as is , mmmmmmmm?

front is at 1 1/2 turns out rear is at 2 turns out , will the swap of the pilots from 45-48 cure the idle circuit lean issues on its own ?

non adjusable needles , the spare carbs i have have adjustable needles , and 180 mains fitted , but as im not chasing bhp , i think i might just stay with the standard jet / needle set up , 175/178

[VTRDark]

Sounds like you have a mix of dynojet mains and standard needles which is not a good mix to begin with as they are designed to work with the dynojet needle profile. What about the slides, is there an extra lift holed drilled out from possible previous dynojet needles?

The pilot will have an effect throughout, more so on the idle circuit but will taper off. With the standard jet / needle set up and 48's things will be just fine. Though you may want to consider shimming the needles. http://www.superhawkforum.com/forums/te ... -up-24769/ 1.5 turns out on the 48's is not enough, approximately 2 1/4 rear and 2.5 front give or take an 1/4 turn should be fine with 175/178 mains.

(:-})

[motostorm]

well i said feck it and fitted the dynojet kit with non drilled slides 180 mains

48 pilots , standard airscrew/fuel screw settings

standard filter and airbox

tps mod done 1024 initial reading


ill probably go back to the standard mains and needles if its pants in the midrange tho

bike sounds different on the bench , still not right giving a small crack to the throttle from tickover , but itll need to be driven

[motostorm]

Sounds like you have a mix of dynojet mains and standard needles which is not a good mix to begin with as they are designed to work with the dynojet needle profile. What about the slides, is there an extra lift holed drilled out from possible previous dynojet needles?

The pilot will have an effect throughout, more so on the idle circuit but will taper off. With the standard jet / needle set up and 48's things will be just fine. Though you may want to consider shimming the needles. http://www.superhawkforum.com/forums/te ... -up-24769/ 1.5 turns out on the 48's is not enough, approximately 2 1/4 rear and 2.5 front give or take an 1/4 turn should be fine with 175/178 mains.

(:-})

thats a good link , one of the first things he says is going to the 48s and installing a dynojet kit wont work , lol

and i didnt realise the standard needles were different , i knew the emulsion tubes were but not the needles



ill drive it before i do anything else ,

[VTRDark]

Talking about the difference in needles, when I last had my carbs apart I checked out the part numbers on the needles which did not match the numbers on the needles for Hawks anyway I measured the two and there is a slight difference in height. I can't remember the measurements right now, but the point is one was a tad longer, .2 or .3 mm or something. I'm wondering if the needle profiles are different for European models hence the difference in part numbers.

With the Dynojet kit, you may get on OK with it as others have had no problems. The important thing is not to drill the extra lift holes and not to use Dynojet springs (only supplied with US kits) IIRC benny done extensive trials with the springs and lift holes and had a lot of problems with it.

Don't forget with 48's you want more than 1.5 turns out. 1-1.5 turns out would be good with 50's.

(:-})

[motostorm]

done 2 1/4 and 2.5

[motostorm]

You Sir are a classy dude and no mistake. In date you say, pure class.

sorry for delay in getting back (food poisoning) but i suppose i is classy innit