A couple of hybrid questions.

[smemly]

i had a look in a spare set of thundercat carbs i have in the garage & i feel slightly more confident in changing jets & having a play.

A couple of questions before i go pulling apart my working carbs, one of which will become obvious when they're on the bench

1 are the needles adjustable, or is this one of the reasons for a dynojet kit?
2 where do i get different size jets for foxeye carbs?

If the jets are adjustable then hopefully i can lean the mixture with the same jet and get some midrange back otherwise, i was going to drop the main jet size down and see if my logic is right.

[Evilchicken0]

Yes the needles are adjustable ... there's a clamping washer on the top which can be put into different positions. Nearer the top and the needle sits further into the jet so the difference between the two surfaces is smaller therefore less petrol and a weaker mixture.

The jets themselves are fixed so they're not tunable once they're in. You move the needle position as above.
if you get to the max setting of the jet / needle you need to change the jet for a different size.

DynoJet sell kits of needles and jets they'll have four or five different size jets and a set of needles which might have a different profile to standard. They're usually brass needles wheras the standard ones can be steel or Ti ... the softer brass ones can be filed in a lathe to alter the profile and get more petrol at a different point in the rev range. The drawback can be if they're not installed properly you can fuck the carbs up and it's also possible to get the needles croked so you can get them to give a consistant mixture anywhere.

[cagiva996]

Smemly have a look at this page for setting up carbs from factory pro http://www.factorypro.com/tech_tuning_p ... gines.html" onclick="window.open(this.href);return false; it may give you some good tips and help setting up your carbs.i used one of their jet kits to set up my first hybrid with titanium needles it cost about 50 quid from straightline racing.before you buy a dyno jet kit check that you dont have to drill a hole in your carb bodies as some of their jet kits you have to do just that to install the kit if your gonna to do it yourself.if you want some standard yam jets get some from fowlers they will do all the sizes you may need.for my first hybrid i ended up with 115 jets and the needles on their weakest setting and it ran ok but was still very rich.if you can afford it do it on a dyno as you will need the patience of a saint as every change you make will need a test ride followed by removing the tank,seat,airbox,carbs and getting soaked in petrol and its a pain in the arse,i would have done it that way but i was too poor at the time! the beauty of the dyno is you can do it all in one hitand get it right after a cuople of hours well worth the money!if you do it yourself write down every change you make as a reference so you dont get confused as to what youve done and end up repeating any mistakes you make-i know this from bitter experience-saying that other forum members have set their hybrids up without too much bother but be prepared to say goodbye to your hair!!!

[smemly]

most likely i'll end up getting it setup properly at one stage, last night i stripped the carbs off again & opened them up, current main jets are 124, so i'll get some 110's and see if that makes any improvement.

It looks like the standard needles have no adjustment, the thundercat ones i have are smaller, so that maybe the only adjustment i can make on that side. If i can get it in the right area then i'll be happy.

Cheers for all your help so far guys.

[w00dzy]

How you getting on now mate

My dyno session didnt go to well..

Dan the mechanic said it was puffing out blue smoke so have since swapped in my spare engine. I decided to buy a stage 2 dyno jet kit, fitted the largest jets (124), drilled the slides with 2 holes and got some piper cross sock filters.

Fitted it all today however the filters are far to big!! Any idea what ones to buy

As for your poor running.. might be an idea to go for a high speed run then check your plugs..

http://www.v6z24.com/mods/howto/images/ ... lugs19.jpg" onclick="window.open(this.href);return false;

They can tell you a lot.. Will help you find out if its running rich or lean up high in the revs.

Its more than likely running too rich.. Maybe swap the 124's out for some 120's?

The peeps at Carbontek are alright, ask for a guy called Dan. Will be taking mine back for fine tuning if it needs it and an Mot. I couldnt find the mixture screw.. I think it involves drilling out a blank plate above it first.

Get some pics up man!

[smemly]

swapped the jets last night, now have some 110's in place. Carbs are now back together and everything built back up. Need to seel the airbox to the carbs again but will try a run around the block first to see if they make a difference.

Was presently surprised that it started and ran well, so at least it would appear i haven't screwed anything up in playing with jets (so far) will update when i get a change to take it out for a spin.

As for pictures, didn't take any of the carbs in bits, did take this one on my phone yesterday as it was sitting in the garage

[w00dzy]

Looks clean mate..

Probably not a good idea to drill the slides.. Think it allows to much fuel to early in the revs as they slide quicker.

Let us know how you get on

[smemly]

Well, finally got out for a quick spin this morning, roads were a bit damp but it gave me an opportunity to test out the roll on response, part throttle and one butt clenching full throttle run. All seemed pretty good. Bike now revs from about 4k to 13k in a pretty linear fashion. No noticable flat spots at the moment.

However a longer run on dry roads might make me think a bit different, i doubt that'll be happening at any point soon.

So, certainly from my standpoint, dropping the standard Foxeye jets to 110's seems to balance out the smaller airbox.

Onto the Brakes, I was planning to try and obtain one from a late model r1, fireblade,zx10 etc etc. I am assuming that all modern day bikes use a radial setup?

[Evilchicken0]

YUp pretty much any radial master will improve the setup, but you might get a bit of an on / off feeling to them depending on the ratio.

I'm going to say .... ford SOHC sump washer if yo need to pad the bar end weight out from the throttle twist grip

[dobbslc]

I've got standard calipers with a 19mm Brembo master cylinder & PFM discs and the brakes are very powerful, even on track after 20 mins.