What to expect when fitting dynojet kit?

[stinkwheel]

Ordered a stage 1 kit for the VFR750 along with a K&N filter. I've been suspicious of it running lean at the top end and it seems down on power since I fitted a stainless exhaust system. Also has a micron "Not for road Use" end can with a shorty baffle.;

I reckon it needs the jetting sorting out but there isn't anywhere within 100 miles of here I'd trust to work on my bike.

Never fitted a dynojet kit before so I'm not sure what to expect. It's one of the more expensive kits for my model so I presume that means there is a lot of stuff in it.

I presume it comes with a guide for which jets to select for some common exhaust/filter combos?

I've got the carbs off for a clean down so I'm ready to fit the kit.

I'm looking for some experience of what fitting a dynojet kit involves. Anyone fitted one? Did you get it right first time or was there a lot of trial and error? (V4 carbs = nightmare to remove/fit) What ought they to have told you that they didn't? What did you find you needed that they didn't supply?

Basically, I'm going to try to fit it at the weekend and I want to anticipate and eliminate as many problems as I can because I won't be able to go into town to get stuff.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Jenks]

Everything will be in the kit, its all in little sections.

youll have each of the jets needed Plus sometimes a drill bit.

Everything will be drawn on the picture diagrame included!

If your not sure, wait till somebody close to you mentions it and see if they can help.

its pretty easy, just do one carb, and one jet at a time!
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1978 MZ TS 250 1 Supa 5
1992 yamaha fzr1000 exup
1998 aprilia af1 sintesi

[Vincent]

I'd have to have it set up on a Dyno. They can be surprisingly cheap, I paid £45 for the dyno and a mechanic - money well spent I think.

[Bikeless]

I done mine myself,as said do 1 carb at a time including the springs and you should be o.k.The only dodgy bit on mine was drilling the slides as they can be brittle,take it easy blowing away any swarf.

Mine recommended the biggest jets(122) with a K+N and an open micron,got it on the dyno and it was way too rich,ended up dropping down to 116's.

[stinkwheel]

The nearest dyno and operator combo who I would allow to work on my bike is a 6 hour round trip in my van away. (There are three closer, one I wouldn't allow to check my tyre pressures, another exuded an aura of extreme disinterest in doing the job at all and the other I have heard nothing at all about).

I'm also allergic to being pissed about by motorbike mechanics and despite the ones I have in mind being competant, I'm entirely confident they would piss me about in some way.

I've never yet arrived at any garage at the pre-arranged time to find them ready, willing and able to get on with it.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Bikeless]

I'm the same,i do everything apart from tyres,don't trust anyone working on my bike.

[Vincent]

[Bikeless]

[Tristan.]

Ooh excellent, posting so I can keep track of this thread.

I've searched for exactly what your asking a few times but never got round to posting it myself.

[Jenks]

[chillpill]

what do you get in a dynojet kit anyway

just jets and a filter ?

[4Stroke]

I've got a factory pro jet/needle set in my zx7 essentially its pretty straight forward but can be fiddley if shimming the needles and tedious to go back and try a slightly different setting.

Your mostly paying for the R+D and making of the needles themselves since the jets are the same as any you could get off the shelf for your carb(likely mikuni or kehin) occasionally you can get better emulsion tubes also depending on kit.

The needles will likely taper earlier to allow more fuel at part throttle positions(mainly mid rpms). And upping the main jet will boost full throttle slightly. They may advise float bowl tweaking for lower rpm increases.

Mixed with a full system and better flowing airfilter then setup correctly you'll have an excellent boost in almost all RPMs and possibly even very low down if they supply the pilot jets though this isn't critical.

Its probably advisable to spend in dyno time with someone who knows carbs well even if it would be out of your way. Whilst its not difficult its just extremly time consuming going back to make slight adjustments. I've dialled mine in well enough finally but to be honest I wouldn't want to make a living out of it without a dyno. Having said that most good manufacturers like dynojet have a database all the setups they have tried+tested which would include most likely ones like system+filter and rely on feedback from others with unusual or alternative setups/conditions so they can usually advise the best settings to your given machine if you supply adequete info so you can avoid tinkering around too much.

Take care.