DYNOJET jets vs FACTORY PRO on 93

[vfrgo]

hey all,

I'm considering re-jetting my stock carbs as I have a full TBR system with what probably will be a Delkevic can, on my 1993 VFR.

Im doing some research and hearing all kinds of stuff about both...

I'm a bit hesitant with the Dynojet stuff because you have to drill your carbs, and I'm not sure about that, but past that is there any other drawbacks?

that being said, what is the Factorypro stuff?

how would these two compare, in terms of performance.

I plan on running sotck air box, and stock filter unless otherwise suggested.

i'd love to hear some people who have some of these mods done on their 90-93. the good and bad, all welcome!

In the meantime I'm gonna go contemplate bike works over a cold one!

[timmythecop]

all either one consists of is some jets, needles and a drill bit. Before you buy a jet kit, try raising yer needles a notch and or going a bit fatter on the main jet. While the carbs are off, drill a tiny hole in the brass covers on each carb and pop the cover off. then you can adjust the air mixture at idle.

[VIFFER93]

I have installed 2 FP jet kits in my 2 93VFRS. I chose them because I did not have to drill out the carbs to install and FP has been really good to work with if I need to order different jets.

I have no experience with any other jet kit with my VFRs so I can not say if they are better or worse then others but I do like the way they work.

[gll429]

the "drilling of the carbs'

is VERY simple.. in fact if you can the carbs on and off with out screaming and crying like a little girl.. then you can use a drill bit that come in the kit and widen the existing "breather' hole at the bottom of the slide.

the other drilling is to make a hole and insert a screw in a plug.. and pull the plug out.

this gives access to the air fuel mixture screws

other than that... both kits are about the same.

[SEBSPEED]

The Factory Pro kit has an OEM-style taper to the needle while the Dynojet needles are shaped differently. People will argue that the FP needles offer better driveability on the street.

FP sends their kit with a sheet of "owner install feedback", which summarizes specific bike details, and how to set up the entire carb for certain mods, along with dyno results. It takes a lot of guesswork out of getting a good baseline.

FP kits do NOT require any drilling.

[NakedViffer]

I put together my own jet kit, I just can't justify the expenditure.. For whats in the kit I think its ridiculous, I'm a prior Carb Tech and I know what this stuff costs, and its outrageous what these guys charge. I got a set of adjustable needles in a like new rack I bought off ebays for $149, spent about $15 in jets and bam, got a jet kit.. I understand I don't get the other jets, but I know what to jet for and those other jets end up never getting used 9 outta 10 times. Plus they are real cheap to buy anyway.

That being said, everything I hear says the FP kit runs better. Also, I think you would be well advised to compliment that exhaust setup with a modded airbox and free flowing filter and then jet for that setup.

[vfrgo]

The Factory Pro kit has an OEM-style taper to the needle while the Dynojet needles are shaped differently. People will argue that the FP needles offer better driveability on the street.

FP sends their kit with a sheet of "owner install feedback", which summarizes specific bike details, and how to set up the entire carb for certain mods, along with dyno results. It takes a lot of guesswork out of getting a good baseline.

FP kits do NOT require any drilling.

I kind of like what Seb is saying here... and I really like the idea of not drilling anything, and being able to return to stock in a snap. Also getting setup testemonials and setup guides sounds good.

Before I started this post, I had already purchased a Dynojet kit. I've received it last night. Seems pretty straight forward, but I'm not sure that I wanna go ahead with it... I don't want to get into a situation where I have to buy an another carb set, to get back to normal... if the kit doesn't work for whatever reason..

I may be just freaking out here and crying like a little baby about a bit of drilling - as VFRDefness put it...

I also looked at the FP website and they offer a titanium set that is supposed to be for a lifetime! only 20 bucks extra...

I'm thinking...

DOES ANYONE WANT TO BUY A STAGE ONE JET KIT BY DYNOJET??

[JZH]

I put together my own jet kit, I just can't justify the expenditure.. For whats in the kit I think its ridiculous, I'm a prior Carb Tech and I know what this stuff costs, and its outrageous what these guys charge.

True...but it's a little like saying that Microsoft Office 2010 is just a bunch of 0s and 1s optically coded onto a DVD.

In other words, the reason why "jet kits" cost a lot more than the cost of their components is due to the time and effort DJ and FP put into developing them. Absolutely, any good bike tuner with a dyno and some 2mm washers should be able to re-jet any carbed bike without using any "jet kit" at all. But it might take him (or her!) some extra time on the dyno (and R&Ring the carbs) before achieving similar results to what the jet kits produce without any dyno time at all. There is a hefty mark-up, but it's not that crazy once you factor in the development and testing time.

Ciao,

[vfrgo]

I put together my own jet kit, I just can't justify the expenditure.. For whats in the kit I think its ridiculous, I'm a prior Carb Tech and I know what this stuff costs, and its outrageous what these guys charge.

True...but it's a little like saying that Microsoft Office 2010 is just a bunch of 0s and 1s optically coded onto a DVD.

In other words, the reason why "jet kits" cost a lot more than the cost of their components is due to the time and effort DJ and FP put into developing them. Absolutely, any good bike tuner with a dyno and some 2mm washers should be able to re-jet any carbed bike without using any "jet kit" at all. But it might take him (or her!) some extra time on the dyno (and R&Ring the carbs) before achieving similar results to what the jet kits produce without any dyno time at all. There is a hefty mark-up, but it's not that crazy once you factor in the development and testing time.

Ciao,

agreed!

looking at carburators, they are the mechanical equivalent of an iPhone - I know roughly what it does and how it should perform, but the actual insides are shrouded in a mystical fog...

thus, I have to bite the bullet on buying a jet kit...

its cheaper then going to mechanic school!!! or quiting my job to become a mechanics apprentice...

but I'm still not hearing any praise of the DJ stuff... how's the performance with the DJ's? Anyone have them on their 3rd gen??

[NakedViffer]

I put together my own jet kit, I just can't justify the expenditure.. For whats in the kit I think its ridiculous, I'm a prior Carb Tech and I know what this stuff costs, and its outrageous what these guys charge.

True...but it's a little like saying that Microsoft Office 2010 is just a bunch of 0s and 1s optically coded onto a DVD.

In other words, the reason why "jet kits" cost a lot more than the cost of their components is due to the time and effort DJ and FP put into developing them. Absolutely, any good bike tuner with a dyno and some 2mm washers should be able to re-jet any carbed bike without using any "jet kit" at all. But it might take him (or her!) some extra time on the dyno (and R&Ring the carbs) before achieving similar results to what the jet kits produce without any dyno time at all. There is a hefty mark-up, but it's not that crazy once you factor in the development and testing time.

Ciao,

You're mostly right, ecept for the dyno part.. In the majority of situations, there is a combo that works good, if you go and check out all of one gen with a slip on and a K&N, they are gonna average the same jet setup on the best running bikes. Its not as advanced as you think. Its certainly a long ways from tuning EFI and modifying the Volumetric efficiency table or tuning a timing curve on a boosted engine. Which in all honesty isn't that hard. I'm not trying to give you a hard time or argue, but I truly believe people make fuel/carb tuning out to be a lot more complicated and involved than it really is.. And while I agree, dyno's are very useful tools, I don't find them very well suited to carb tuning. they are great to be able to say I put down XXX amount of power, but there are so many variables in the mix between bikes, tires, dyno drives.. They are really better to get a baseline number and test gains. Now if you are tuning fuel injection and need to do low fuel trims for cruising and part throttle, using a wideband among other sensors, dyno's are invaluable.

Personally, I've dyno'd quite a few bike and jetted at the dyno runs too, but they don't simulate real world conditions, you always end up jetting at the track and getting faster. and thats why I prefer to tune at the dragstrip, between trap speeds, 60 foot times, and ET, it works great. I've never seen a bike jetted on the dyno and be at its best running, fastest state without further attention.

Keep in mind, this is just me, not everyone feels comfortable tuning their own bikes, or making passes on a dragstrip for that matter.

[JZH]

You're mostly right, ecept for the dyno part..

Given that I've never been in a dyno room in my entire life, I'm happy to settle for being "mostly right"!

Ciao,

[vfrgo]

ok,

so aside from technical disagreement on how complicate/not a piece of mechanics the carbs are, is there any testemonials of DJ users, or someone who's used FP and DJ stuff?

would like to hear what if any difference is between them in terms of performance...

[NakedViffer]

I've been researching (google) like crazy today and I can't find any hard evidence that one is better than the other. Everyone just says the Factory kit is better because so an so said so, which is the type of crap I don't buy into. I'm also learning that the slide drilling with the DJ kit isn't needed and arguably makes the bike run worse. Apparently from what I've read, they don't come with those drill bits anymore either. I have the Dynojet style needles and I haven't gotten to ride my bike yet.. That should happen this coming week and I'll let you know how they run. They seem to run great in neutral though! Keep in mind I haven't altered the slides and have no intention of doing so. The only thing that will accomplish is making the needle move up faster, and the way they are tapered, I would say thats gonna cause too big a rush of fuel into the engine.

[gll429]

drilling the slide allows the slide to lift faster.. giving you a hard hit when you wack the throttle open. thats it! if you a SMOOOTH rider then it will still be smooooooth.

[NakedViffer]

drilling the slide allows the slide to lift faster.. giving you a hard hit when you wack the throttle open. thats it! if you a SMOOOTH rider then it will still be smooooooth.

Have you actually done this mod and tested against stock? Because the effect its gonna have is making the slide a lot more sensitive to pressure change, thus yanking the needle out of the tube at a faster rate, which in turn will increase speed of fuel delivery, i.e. a huge shot of fuel. Depending on a couple things, mainly RPM and throttle position, this will likely make the bike stumble, especially with their style of jet needle. So I have to kindly disagree with the smoothness comment, because we don't own sport(y) bikes to have to roll the throttle on slow and smooth all the time, most of us like to be able to whack that throttle when we please and get a lunge forward, not a stumble thats likely to mash your face on the windscreen because you are bracing and countering for what was supposed to be a neck snatching surge forwards..

[gll429]

yup, i am a certified honda tech.. worked in shops with a dyno.. and i dyno tuned bikes.. the "huge shot " of gas as you say.. is UP TO YOU!!

put the clip where you want it.. add washers or not. put the jet size YOU want.. in other words.. read the set up instructions that match what you have on your bike.. and go from there.

[NakedViffer]

yup, i am a certified honda tech.. worked in shops with a dyno.. and i dyno tuned bikes.. the "huge shot " of gas as you say.. is UP TO YOU!!

put the clip where you want it.. add washers or not. put the jet size YOU want.. in other words.. read the set up instructions that match what you have on your bike.. and go from there.

I still don't think you understand what I'm talking about, its not up to you.. Needle position and jet size have nothing to do with what I'm getting at. The holes in the bottom of the slide are metered so that the CV slides go up evenly with how the motor responds. Changing jets and changing needles or position does not warrant changing the rate of movement on that slide. Everything the user needs can be achieved without touching that, it might be beneficial in an engine with a higher brake specific fuel consumption like a turbo motor that needs the delivery to come on quicker. Anything outside of that, its not helping. And while I respect the fact that you are a Honda tech, I am a carburetor technician, and have built/tuned carburetors for hundreds of applications.

I'm gonna leave it at that though, take it for what its worth.. I didn't state my opinion for argumentative purposes as I'm sure you didn't either. I'm just trying to help the OP make a more informed decision.

[gll429]

i understand perfectly.

however.. the hole lets the slide move faster..

thats it!!!!!!!!!!!!

you control how much gas comes out an any given slide position by changing the needles or jets and playing with them

as for getting the slides work evenly.. that why you sync the carbs. and yes.. honda tech.. for 20 years now..and worked on every brand out there.. my point.. its not brain surgery and it doesnt make it a like a cbr 1000 either.

now THATS a bike with a huge hit of gas.

[gll429]

hey all,

I'm considering re-jetting my stock carbs as I have a full TBR system with what probably will be a Delkevic can, on my 1993 VFR.

Im doing some research and hearing all kinds of stuff about both...

I'm a bit hesitant with the Dynojet stuff because you have to drill your carbs, and I'm not sure about that, but past that is there any other drawbacks?

that being said, what is the Factorypro stuff?

how would these two compare, in terms of performance.

I plan on running sotck air box, and stock filter unless otherwise suggested.

i'd love to hear some people who have some of these mods done on their 90-93. the good and bad, all welcome!

In the meantime I'm gonna go contemplate bike works over a cold one!

you didnt say WHAT YOU WANT!!!! if your going to run a stock filter your getting much if any gain from your exhaust pipe. ..aside from less weight. you need a better filter to get any gain from the jetkit.. however...

WHAT DO YOU WANT?? faster bike? better response? a bigger hit for passing power? smoother transition in speed? all can be done by playing with carbs and other stuff.

now remember.. you have to stop by my shop so i can take it for test ride and give you an expert opinion on how you did.

[gll429]

and by the way.. the dilling out of the slide hole.. its going from 1.5 mm to 1.75mm or something like that. it not going to to 1/2 inch!

[vfrgo]

hey all,

I'm considering re-jetting my stock carbs as I have a full TBR system with what probably will be a Delkevic can, on my 1993 VFR.

Im doing some research and hearing all kinds of stuff about both...

I'm a bit hesitant with the Dynojet stuff because you have to drill your carbs, and I'm not sure about that, but past that is there any other drawbacks?

that being said, what is the Factorypro stuff?

how would these two compare, in terms of performance.

I plan on running sotck air box, and stock filter unless otherwise suggested.

i'd love to hear some people who have some of these mods done on their 90-93. the good and bad, all welcome!

In the meantime I'm gonna go contemplate bike works over a cold one!

you didnt say WHAT YOU WANT!!!! if your going to run a stock filter your getting much if any gain from your exhaust pipe. ..aside from less weight. you need a better filter to get any gain from the jetkit.. however...

WHAT DO YOU WANT?? faster bike? better response? a bigger hit for passing power? smoother transition in speed? all can be done by playing with carbs and other stuff.

now remember.. you have to stop by my shop so i can take it for test ride and give you an expert opinion on how you did.

well,

I had the exhaust only on the bike last season and it ran sort of fine... it Idled well, and it accelerated well, but it would pop on desceleration and it seemed like the bottom range (taking off from a stand still) was lacking compared to stock. Now, i did have exhaust leaks, as the old exhaust sytem doesn't fit well, and I haven't discovered muffler sealant stuff.. this year I'm better informed.

Also, while I was taking off my carbs, I've discovered that one of my carb insulators (boots, or the rubber things that connect the carb to the engine) had some imperfections (gouges of sort) running perpendicular to the groves that allow it to seal to the carb and engine. This in turn made that whole side of the engine mucked up with a fuel/road grime mix... It also, more importantly, probably means that some of my bikes sub par performance was due to one cylinder getting a less than optimal air/fuel mixture.

now keep in mind I haven't ridden any other VFR to compare my bike to, but from what I understand this bike should not be topping out at just over 200km/h (under 120mph), it should be passing that mark with relative ease. I havent found that to be the case.

So, as to what I want,

I want to get rid of the pop on downshifts, I wan to get a butter smooth idle (after a carb sync, that should take care of that), and I want to achieve that beautifull linear power delivery all the way up to over 10 000 rpm...

If by re-jetting I will get to this (which is what the DJ jets promise to do), and if I get a bit more power, that would be great!!

I don't really want to keep chopping parts on the bike, as bottom line is I trust the engineering of honda's engineers when they put this thing together more so than my guessing at how many holes I have to drill into an air box... or whatever....

I would prefer to do this with as little alterations to the stock parts as possible.

so a good combination of a aftermarket filter, or filter screen removed or whatever needs to be done to make the combination that I have (a well running 61 000km VFR, ceramic coated 2 bros headers, custom high mount midpipe with a Delkevic CF stubby can) work well is what I'm looking for.

I'm installing the DJ kit this weekend.

I think that I'll do it without drilling the slides, first, then check the bike performance (once the bike is back together) with stock filter and snorkel and all that, see what it's like on the street and highway, then if there is still more to be desired, I will deal with the air delivery system...

sorry for the lengthy response...

gll429 I may contact you today throughout the day as I progress with the DJ instal.

Nakedviffer and gll429 I'm intersted in what you both think would be the thing to do with the air box and air filter... what would give me most out of what I have with least amount of airbox mods....

thank you both !!!

really enjoying this 'healthy discussion' tween you two - and learning a few things along the way!

cheers,eh!

[gll429]

Ok :)

A few things...

Do you have a mig welder?? Even a cheap one?? If not call your pals and borrow it..

The "sealer" stuff sucks.. All of them.. Sooner or later they get baked to death and fall off. Weld up any holes and cracks in your headers..

Have you DEpaired your bike???

If not .. Read my TOPIC on it. you will want the mig welder for that too.

Air box.. Leave it stock. Or remove the snorkel.. I tested both on a dyno no difference. And that was with the DJ kit a K&N filter and a vance&hines slip on.

intake boots.. When you pull the carbs. Check the INSIDE of the boots.. Make sure no cracks..

Out side can be chewed up to a point.. .

When you reinstall the carbs.. Put the boots in HOT water..makes them soft.. Lube the ports on carbs install the front FIRST.. Pop them in...

Then do the back.. You may need to use 2 LONG screwdrivers with FLAT blades.. Place at the back of the boot lower carb.. And PRESS down the should slide in .. Remove drivers and install clamps :) lube your cables.. Adjust cables so you have about have a 3mm play in rotation.. Have fun!!

[vfrgo]

Ok :)

A few things...

Do you have a mig welder?? Even a cheap one?? If not call your pals and borrow it..

The "sealer" stuff sucks.. All of them.. Sooner or later they get baked to death and fall off. Weld up any holes and cracks in your headers..

Have you DEpaired your bike???

If not .. Read my TOPIC on it. you will want the mig welder for that too.

Air box.. Leave it stock. Or remove the snorkel.. I tested both on a dyno no difference. And that was with the DJ kit a K&N filter and a vance&hines slip on.

intake boots.. When you pull the carbs. Check the INSIDE of the boots.. Make sure no cracks..

Out side can be chewed up to a point.. .

When you reinstall the carbs.. Put the boots in HOT water..makes them soft.. Lube the ports on carbs install the front FIRST.. Pop them in...

Then do the back.. You may need to use 2 LONG screwdrivers with FLAT blades.. Place at the back of the boot lower carb.. And PRESS down the should slide in .. Remove drivers and install clamps :) lube your cables.. Adjust cables so you have about have a 3mm play in rotation.. Have fun!!

hmmmm...

no welder... and nobody I know has one...

but, what I'm talking about is the stuff that is used at a connections of pipes. the pipes themselves are great, no pin holes in them or anything... just need something to give an air tight seal where back two headers meet the front headers, by my right foot, and where the midpipe meets the headers on the left side...

As for the DEpairing thing, I've been baffled with that, for a long time, ever since you told me about it.. still don't see what that is... maybe i'm just being stupid, but I've looked the engine block over and don't really see where these pair holes are??? do you have a picture of it?

so, K&N filter is the way to go?

I guess I'll do that...

and the carb boots are all good except for the one, which was gashed on the inside, and across the groves... I'll take my time and great care when installing the new ones so that i don't do the same... I read somwhere that Vasaline does a great job of protecting and restauring rubbers and plastics... so should I put a bit of vasaline on the inside of the heated boot when re-installing back? or armorall? either way, ill do whatever i can to protect them and to make sure they have a good seal.

I guess, later this summer I may have to bring her to washington so that you can dyno her and see how well we did!!

thanks much for the tips tho!

Didn't get to the DJ's today, had my hands full with my new Spiegler steel braided brake lines... I installed them and when it came to putting brake fluid in, it took me a looooong time to work up some breaking power and to get the air out of them... the front is reall good now, but the rear still has a lot left to be desired... also bought some sort of hydralic brake thing.. supposed to be used to test hydraulic pressure in hydrulics on cars but says it can be used to refill brakelines... except when I tried to use it, it just made a mess and I resorted back to what i knew how to do... it took me a looooong time tho... and a lot of pumping of the brake. but its getting there now.. i think that there is still some air in there, but won't that rise up over time? the bike has three weeks now of just sitting till i come back from europe...

[gll429]

om sent on depairing the bike.

if you put vasoline on the boots.. do so before heating. it wont wash off.. then install the carbs FAST!

filters.. K&N have a very good rep.. the newer companies may be getting there.. b&m or something..

uni makes a sheet foam filter.. but it is not quite as good as catching all the dirt.

[vfrgo]

om sent on depairing the bike.

if you put vasoline on the boots.. do so before heating. it wont wash off.. then install the carbs FAST!

filters.. K&N have a very good rep.. the newer companies may be getting there.. b&m or something..

uni makes a sheet foam filter.. but it is not quite as good as catching all the dirt.

hey, got the pm,

ok, so I have a good feeling that my bike isn't depaired... but now wondering what the purpose of the pair is if you can just take it off without any ill effects? and why is it imporant to take it off? kind of confused... i'm open to the possibility, but want to understand why I'm doing it...

thanks..

[gll429]

the pair set up pumps cold air into the headers.. the cold air ignites any unburned gas.. a nd makes that popping noise when you close the throttle. it never worked very well in the first place and can be removed with out messing up your bike.