• Jetting Guru's....

Posted: **Sun Jun 15, 2008 5:31 am**

I finally purchased a Factory Pro Jet Kit to get rid of the bogging on my RVF, so now I need to know what the Jetting Guru's advice is for a starting point. Here's the particulars:

Engine Mods/Info:
Engine newly rebuilt with all new pistons, rings, valves. Pistons have friction reduction coating on the skirts, ceramic coating on the crown- both for heat reduction. Front and rear head pipes are coated inside and out with ceramic coatings to make the heat go OUT the exhaust instead of radiating from the pipes. Exhaust is a Yamamoto half system with a single carbon can. Stock air filter. When I say newly rebuilt, I mean it just passed the break in miles.

Although this may not change the starting point any, I think that I should share that I don't want absolute top end power, I want best drive-ability for the street. That being said, this bike will be ridden when ambient temperatures can get to 105 degrees F.

It typically bogs hard when a stiff head wind+high gear+5,000 RPM meet. I can usually ride around this problem, but if it starts to bog I have to down shift, most of the time twice, to get it to pull out of it.

Please Jetting Guru's

.... help me.....

Posted: **Sun Jun 15, 2008 10:41 am**

Does this kit include the emulsion tube / needles what size bellmouths are used and are you running a filter?

are the pistons oversized?

if so how many holes are present in the emmulsion tube? and what is the FP needle code you are using.

Posted: **Sun Jun 15, 2008 12:05 pm**

I don't know too much about rvf carbs, but yours don't sound right.

I would stay clear of the Factory brand kit, you'll get just as get (if not better) results with the oem stuff. Not sure about the rvf kit, but the nc30 kit is known to be not much good.

Make sure that the carb settings are optimal before changing any parts, i.e. cleaned/fully functional (no blocked passageways [air jets!]) pilot screws set to std and balanced etc. Check the pilot jet and main jet sizes so you know what's in there.

Many of these bikes have changed hands and been mucked around with along the way, the only way you'll know what's in there is to take a look.

The mods you have should only require minimal fuelling changes, most jet changes on these bikes are purely based around induction mods, exhaust/engine mods to a much smaller extent. Is the airbox completely standard, front flap, snorkel and all?? Modifying these parts is where a lot of people run into fuelling glitches.

All in all, the bike should run/fuel sweetly if the above is all good, you may need to tinker with the pilot screw setting to find the optimal, and maybe also raise the standard needles which will richen up the rev range slightly where you're having problems.

Posted: **Mon Jun 16, 2008 2:05 am**

I'm interested in the responses here also. Stickshift are you saying stick with the standard 108 jets and just fit an extra shim under the needles? I've read that somewhere else here before. Don't bother cahnging to 110 jets? I'll be running stock air box, stock filter, and race can. I shouldn't bother with a jet kit, either from Factory Pro or someone else? If so, where can you buy the .5 mm shims? CaliRVF re-jetted and I would be interested in knowing what he used. Cali?

Posted: **Mon Jun 16, 2008 3:20 am**

RVFHooligan wrote: Stickshift are you saying stick with the standard 108 jets and just fit an extra shim under the needles? I've read that somewhere else here before. Don't bother cahnging to 110 jets?

You should certainly increase the main jet size, 112's all round would probably be on the mark with your setup (depending on altitude, etc). What I meant was that these sorts of mods only require a relatively minor change (due only to your slightly freer flowing exhaust) compared to those that run no airbox/filter etc (145+ size jets).

Raising the needles helps with the lean midrange flatspot. I can't remember if rvf needles are adjustable (anyone?), if not just raise them with a washer. The washers are a common hardware shop part, just make sure the needle fits through and that they seat properly! If you have trouble finding some, some of the other US members might be able to help.

RVFHooligan wrote: I'll be running stock air box, stock filter, and race can. I shouldn't bother with a jet kit, either from Factory Pro or someone else? If so, where can you buy the .5 mm shims?

Forget the Factory Pro kit, the needle taper and diameter is changed (and economy is poor apparently). All you really need for a good street setup is slight mods to the standard gear. Jets can be had from any Keihin dealer, and will be an off the shelf part (99101-393 series)

Raising the needles and jetting for a safer top end will give good results.

Posted: **Mon Jun 16, 2008 4:14 am**

RVFHooligan wrote: CaliRVF re-jetted and I would be interested in knowing what he used. Cali?

Mine was done when I bought it ..

Posted: **Fri Jun 27, 2008 2:17 am**

Stickshift wrote:I don't know too much about rvf carbs, but yours don't sound right.

I would stay clear of the Factory brand kit, you'll get just as get (if not better) results with the oem stuff. Not sure about the rvf kit, but the nc30 kit is known to be not much good.

Make sure that the carb settings are optimal before changing any parts, i.e. cleaned/fully functional (no blocked passageways [air jets!]) pilot screws set to std and balanced etc. Check the pilot jet and main jet sizes so you know what's in there.

Many of these bikes have changed hands and been mucked around with along the way, the only way you'll know what's in there is to take a look.

The mods you have should only require minimal fuelling changes, most jet changes on these bikes are purely based around induction mods, exhaust/engine mods to a much smaller extent. Is the airbox completely standard, front flap, snorkel and all?? Modifying these parts is where a lot of people run into fuelling glitches.

All in all, the bike should run/fuel sweetly if the above is all good, you may need to tinker with the pilot screw setting to find the optimal, and maybe also raise the standard needles which will richen up the rev range slightly where you're having problems.

The only mod I made to the induction system was to remove the chunk of foam from the Snorkel becuase it was deteriorating quickly. outside of that the front flap is there, the airbox is stock, and the air filter is OEM (although I am currently looking to find a same sized K&N to adapt to an old filter). I heard that making all four bellmouths the same size(short) will give gains, and have some more stock short ones. So after reading all of your posts, the questions are;
what size jets should I order?
how far should I raise the Needles?
should I drill the slides?
does the (lack of) snorkel foam affect anything?
would making all 4 bellmouths short be ok?

Thanks

Posted: **Fri Jun 27, 2008 2:55 am**

Welcome Goinphaster! Glad to see another member from the US on this board. I just received a set of 110 jets today in the mail from PJMotorsports and I ordered .5mm and 1.0mm carb shims from Rick Oliver. These are relatively mild changes. The bike will be bone stock except for the end can. I've cleaned the carbs inside and out and manually/visually synched the carbs by measuring the gap on the butterflys with a feeler guage. I'll hook them up later on when the bike is running for a final check. I'll change the jets and shim the needles this weekend and that should be a good starting point. I can make changes from there depending on how it goes. Of course, it will be a few months before I can report back on how she runs.

Posted: **Fri Jun 27, 2008 4:04 am**

Goinphaster wrote: what size jets should I order? 112's all round will be fine
how far should I raise the Needles? O.5mm, easiest with a suitable sized washer *This is with standard needles only.
should I drill the slides? No
does the (lack of) snorkel foam affect anything? I don't know what this is, there shouldn't be any in the intake. Is it at the front or back of the airbox?
would making all 4 bellmouths short be ok? I don't think there's much to gain. Probably best to swap them only once you have it running sweetly to notice any difference.

Posted: **Fri Jun 27, 2008 5:02 am**

Stickshift wrote:
Goinphaster wrote: what size jets should I order? 112's all round will be fine
how far should I raise the Needles? O.5mm, easiest with a suitable sized washer *This is with standard needles only.
should I drill the slides? No
does the (lack of) snorkel foam affect anything? I don't know what this is, there shouldn't be any in the intake. Is it at the front or back of the airbox?
would making all 4 bellmouths short be ok? I don't think there's much to gain. Probably best to swap them only once you have it running sweetly to notice any difference.

OK, found a good site to order the jets, but which jets are they? Pump Jets? Idle Jets? Needle Jets? Air Jets?

Thanks.

Jetting Guru's....

Jetting Guru's....

Re: Jetting Guru's....

Re: Jetting Guru's....

Re: Jetting Guru's....

Re: Jetting Guru's....

Re: Jetting Guru's....

Re: Jetting Guru's....

Re: Jetting Guru's....

Re: Jetting Guru's....

Re: Jetting Guru's....