Olafsson

Hello
I´m new here, I have got a 98 VTR 1000 last week , really good condition ,23000 mil , with a open system on it, stock filter, don´t know more at this moment.

I´m new to twins, love the sound, but it feels like it´s not much power in the bottom at 2000-3500 rpm, compared to my RF 900 it feels less powerful , According to tests I´t should be powerful to do a power welly on 2 gear but there is no way on this bike.
Can some one let me know what to expect??

The choke don´t stay open by it self I have to hold it is that correct function on the VTR?

I will do the suggested mod in the thread this winter, I have not opened the bike yet but I can´t find info where to connect the houses for sink carbs. I can´t find that in Service manual either , is there some pictures on where to connect?? I want to have all the necessary hardware at home before I start

Thanks From COLD Sweden
Tomas

basford

I did the 48 polit jet, .04 shims and TPC adjustment and it made a world of diffence in crusing around. Stopped the coughing surging and is smooth. I'm not sure what the true potential is for these bikes either, but mine too doesnt take off it get over 4K or so.
tighten the set nut on choke to get it to stay on.
For sinking carbs you can use the vac line leading to the fuel petcock for the rear, the front is a pain. There is an allen bolt just below the rubber boot were the carb slides in on the right side of the engin. I've been putting the fitting on with the carbs off. After I sinking I have been using some rubber tubing over the head of the allen bolt to fish the bolt back into the vacume hole so I dont have to pull everything apart again.

basford

Stock cab setup did the #48 idlel jets and set front and back needles up 0.04 and did TPC to 490, have stock airfilter, and devil upswept exaust.
Bike runs nice and is smooth. I commute with it and like lower end performance.
Two questions
1) What does setting the rear needle up to 0.06 do? (leaving the front at 0.04) Should I raise it?
2) Will putting a taller stack on the front carb give me anything. (to clarify, is the post about a longer stack is refering to getting a second stack to match the rear one? sorry to sound dumb but the stack is what bolts between the airbock housing and the filter the plastic piece that has the tabs that cover the screws holding the airbox to the carbs?

NZSpokes

I am going to try this. My stock filter is in bad shape and i got a K&N that was unused.

I also have done all of this mod but have to run 3 turns out to get a steady 4k rpm cruse without surging. Im in New Zealand at sea level so this may have something to do with it. I will try going up one size main and start again from scratch.

gab

hi guys i just finish tune my carbs with a wideband. well fine tuning since i was pretty close before.

1999 with stock engine
airbox mod with bigger opening and no snorkel
velocity stacks
mig slip on
42 slows
178/180
needle 20 shim F & R
one hole in the slide both f and r
thumbs fuel srew

quillinsmat

so i did a major engine rebuild a couple years ago and never having owned anything with carbs before when it got to the tuning stage i took it to the local honda shop. They asked if they could put in a KN filter and dynojet kit, i hadn't found this forum yet and i just told them " make it run". so now after tearing into my carbs a couple times for cleaning e4tc. since and having read (almost) this whole sticky i'm wondering what would the drawbacks be of following hawks setup but using the DJ spring? It's way easier to install the slides with that short spring lol.

8541Hawk

Some have gotten them or say they have gotten them to work but that hasn't been my experience.

The short springs cause a rich mid-range condition IMHO.

The English guys that do run the DJ kits run the stock long springs and don't drill the extra lift hole and report good results.

NZSpokes

I use 8541Hawks set up now as my base line. I know the motor runs very well from there so any changes that dont work I go back to it.

NZSpokes

A question Hawk. As it seems the slides open a bit fast making for a rich mid range, would packing the spring for more preload help? Just a random thought.

And is a DJ needle a lot different to a stock one?

8541Hawk

Well you could try it but I believe they would still open too fast. The folks that run them (that I know of) run the stock springs and also do not drill the extra lift hole but I haven't tried that combo and it has been around 16 years since I pulled the DJ kit out of my bike.

As for the needle, they look very similar but you would need something like an optical comparator to really know for sure. IMHO I think the DJ needles have a slightly larger O.D. which them allows for them to run a larger main jet so you can say...oh my mains are bigger than yours.....like it really matters but you know how people are about stuff like that.

NZSpokes

Good point on the needles, DJ kits do use big mains. I may pop round to a carb guy I know and see if he has some stronger springs from another model. Just for giggles.

sjscicluna

Love your work keep us posted wight the results

CrankenFine

Mike,

I just completed this setup yesterday, using single lift hole mod front and rear for Dr.Honda velocity stacks. I am also using 48 slow jets with stock main jets, stock needles and springs, .040 lift on the rear needle and .030 on the front.

Initial impression from first ride today is very satisfying. Bike seems to pull strongly across the entire RPM range. 6th gear roll on from 70 to 90 mph was surprisingly quick. I did not feel ready to run WOT yet as the front end was getting very "light" in first and second at a freeway on ramp.

The bike seems to warm up quicker but then runs a few degrees cooler than normal once fully warmed. The only thing I have not sorted yet is attaining a strong steady idle rpm before it's fully warmed from a cold start. When I was opening vac ports to attach synchronizer tool idle immediately jumped so I probably set idle mixture too rich. Have to travel on business Monday &Tuesday so likely will not sort this part til later in the week.

Thanks for providing your write up for this level of tuning. I am glad I spent the time to do this, it was worth it.

ssscottyyy

So my bike is suffering from the dreaded "clunk-die." When it doesn't fully die, it makes the bike give an aggressive jerk at low speed rolling or turning, and then continues on. Other times the bike will just cut off and will start right back up when hitting the starter no problem.

So now I am going to attempt to mess with the carbs. Ordered #48 series 21 jets, will be shimming the stock needles, and will be adjusting the mixture screws accordingly. Hopefully this will cure the dreaded problem I am having because it really makes me get really annoyed with this bike.

7moore7

Make sure to sync your carbs when you're done too. The richer pilots as well as sync'd carbs both in combination both have the biggest effect on my carbs as far as gettting rid of the farts (still happens once every few rides).

8541Hawk

Glad you had good luck with the set up. Two things, if I read your post right, it is normal for the idle to jump when you open a vac port to hook up the gauge.

Though you still might be rich down low if you ran the pilots at the base line setting. The Dr. Honda stacks normally run with the pilots in 1\2 a turn from the stock plastic stacks.

ssscottyyy

Farts...do you mean the backfiring or do you mean the bike cutting off? My bike farts quite a bit right now. Probably from running lean?

NZSpokes

Question Hawk, Im going to do a track day at at a place 1100 feet above sea level. I live in a place on the coast. Reckon I will need to change mains or will leaning off the idle screws will do it?

JamieDaugherty

1100ft is not enough to make a difference. I'd just run it as-is and you should be fine.

xeris

I have read the set up guide several times and the whole thread a couple of times. I have eliminated all the other text to be able to focus on the two quotes I have marked. I don't believe that I'm taking them out of context, but maybe I am.
Number one makes sense to me, by its self. Engine in stock tune is a little lean for best performance. Number two also makes sense, again by its self. When I look at both together they contradict each other.
So the questions are: Is the rich condition in #2 a result of the larger pilots and shimmed needles? Is blocking one hole in the front slide a way fine tuning the change in pilots and needle postilion? Or something else entirely?

cybercarl