-EDIT- PLEASE READ LATER POST. HELP NEEDED -EDIT-

My dynojet kit arrived today. I have two questions about fitting it.

1) There are 140, 144 and 150 main jets. Which should I use? I have a foam filter without an airbox and I have an equal length 4-into-1 manifold witha straight through can.

2) It says to epoxy closed the "brass main air jet" near the "aluminium bell mouth boss". Both Haynes and the R1 sevice manual say that there is a "pilot air jet" near the trumpet. Is this what they are talking about?

[Edited on 18-1-2006 by smart51]

[Edited on 30-6-2006 by smart51]

I think this is the top view of the R1 carb, hope it helps:
Rescued attachment untitled.JPG

Hi,

I would put in the 144 mains to start with - it should get you thereabouts until such time you can check it on a rolling road.

Regarding which jet to block up, I'm pretty sure its the smaller of the two jets that you cannot screw out i.e. the pilot jet in the picture above. Just to be extra sure I would seek confirmation of this with TTS or another person on this site who has done it more recently than me.....

Cheers

Paul

The instructions read:

4) remove the float bowls, locate the standard main jet and remove. Replace with a 144 main jet, [I should have read this more thoroughly] and refit bowl.

5) Locate the fuel mixture screw undeneath each carb at the front next to the float bowl. Turn in or out to obtain the best idle.

6) Remove the aluminium bell mouth boss (2 screws). Using more of the epoxy, blank off the brass main air jet. Refit bellmouth boss.

The only thing I can think this means is what haynes calls the pilot jet near the trumpets. I though I'd better check before doing it.

nothing gets blocked off in the float bowl,,its the air jet .when the carbs are on the bike look into them and it will probably be at the bottom of the opening

Oops, sorry you did say main air in your first post.
Might be worth doing a how-to when youre doing it with piccys to help peeps in future. Its an often asked topic.
Are you balancing the carbs? Doing the same to each should in theory not throw the balance out, but Im not sure how open to problems "Turn in or out to obtain the best idle" is. Might be worth it for piece of mind
I think I might still have a kit here for that if I hunt hard enough.
Rgds

Rich

[Edited on 14/1/06 by RichieC]

I have fitted the dynojet kit a described. 144 main jets, new needles on groove 2 (counting from the bottom). Blocked up 1 hole on the slide and the air jets near the trumpet bosses.

It sounds wrong at idle. Very stacatto. It doesn't seem to matter where the idle screw mixtures are set.

At 2500-3000 it sounds like a machine gun. It doesn't like driving at these speed and in 1st (2000 = 9mph ish) it kangaroos like crazy.

at higher revs it is better and runs without coughing or spluttering. (without the dynojet kit it used to at full throttle at high revs).

Any ideas what is wrong and how I can fix it?

I think you should take your car to the rolling road and get it properly set up and as they set it up ask them what there doing so you learn aswell

quote:

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Originally posted by zxrlocost
I think you should take your car to the rolling road and get it properly set up

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you have blocked the pilot jet and not the air jet

the air jet is underneath the trumpet ,take air box off look underneath one of the trumpets and its the only one there

144 jets on the outer 2 pistons and 150 jets on the inner two pistons..

They run hotter so need a richer mixture...

Sounds like you have blocked the idle jet not the main air jet...

So the main air jet is inside the throat of the carb, between the trumpet and the throttle butterfly? Where is the other end of that? I'd rather no put epoxy in the airflow in case it comes loose and gets sucked in.

"even an idiot can fit a dynojet kit and get it right"

On another subject, I don't actually have any trumpets as none came with my engine, I just have the trumpet bosses. Do I need them? Will they fit under my foam filter?

there are 2 big oval holes on the out side of the tube where the butterfly is ,the air jet is down one of the holes,,damn it i wish i could explain better,cant load a picture into my archive

From memory, you can block the correct hole through the slots in the trumpets (as stated by OX), this is what I did. Picture is below with an arrow to the hole to block up (I think this is correct, OX please confirm as my memory is not as good as it used to be and I've since sold the car!).

Notice that the trumpets have been turned down and radiused - this means you can fit a low level foam filter OK and is supposed to give you a bit more top end (at the expense of some midrange)

Cheers

Paul
Rescued attachment Carb hole.JPG

I've just spoken to TTS on the phone. There are two holes, the main air jet and the pilot air jet. the pilot air jet is the removable one (and the one that I blocked). The main air jet is the other. Thanks for the pic

The grooves in the needle count from the top not the bottom, they said, so I have to change that too

Their instructions could be improved then.

I was looking for a pic to help you out on t'internet but failed dismally....

As the trumpets are difficult to remove without damaging them, I fitted the resin into mine by pushing it into the jet with a matchstick. It seems to have worked fine!

I must agree that the instructions are a tad vague though......

I've done it properly now and it seems to be better although the noise is different at idle. I went out in the rain and no kangaroos but my head was frozen before I'd got a quarter of a mile from home so no speeds over 30 or revs over 5000. I'll go out tomorrow when its dry to see how it runs.

when you drop my silencer off i'll see if i can borrow these just to ballance the carbs,i dont work at the place any more but they might let me



and then i'll have a play with your mixtures ,,its no rolling road set up but it will do untill you get it done

Thanks OX

Balancing the carbs may well help, but I believe that the kit does make the idle a little "rougher" than normal until its really well warmed up. However when its on the road it will fly!

Well done on getting it fixed in the end.

- Paul

It isn't raining today so I've taken the car out but it isn't good. It doesnt rev cleanly at any speed. It will stall if trying to pull away at 2000 RPM which it would do effortlessly before (I have to be gentle when taking it out of the garage).

From 3000 RPM the acceleration is rough with lots of harsh vibration in through the chassis and it doesn't want to cruise below 3500.

From 4000 RPM at any throttle above a tickle it makes a deep growling noise like someone pressing the lowest note on a pipe organ that is lower than the normal noise of the engine and it follows the pitch of the engine all the way up through the revs. It sounds a bit like a resonant vibration but mainly it just sounds broken.

Things do improve slightly as the revs build but the car doesn't accelerate nearly as much as before from 5000 RPM. Perhaps half to two thirds.

Help

what might the problem be?

I have removed and cleared out the idle air jets, making sure no debris got into the hole and I've blocked up the main air jet correctly now.

I can't take it out on the road as it is. It is just undrivable.

I tried setting the fuel level more accurately and I removed all the jets and made sure they were clean. It made a slight difference.

So I put it all back to standard, except for the epoxy on one hole in each slide. Everything is back to normal now. sound more like a sewing machine with none of the bad low frequency noises. pulls at low revs again. warp speed is back to how it was. It is so much quieter and sweeter now than with the jet kit fitted that I've doubled my estimate of how bad it was.

It is back to "normal" at not being right at full throttle at full revs though. Any ideas what I should do? perhaps 140 jets instead of the 144s? I'm not sure why that would affect the idle and low throttle though.

[Edited on 19-1-2006 by smart51]

As you are not far from TTS at Silverstone, I would be tempted to take it to them and their rolling road and get it sorted once and for all. They charge £45 +VAT per hour for the rolling road session - pretty good compared with others I've seen. You'd need 2 hours max

- Paul

Success. I refitted the kit with the smaller 140 main jets. was fine below 3500 RPM and below 30 MPH and below 1/4 throttle, but not above. Phoned TTS, whose dyno is still being upgraded (and will be for some time judging by the disapointment in the guys voice). They suggested richening up the needles all the way. Hey presto. No spluttering, smooth reving all the way up at all throttle positions. Smooth response to openeing and closing the throttle at different rates. I think I will get it dynoed when they're back up and running.

Not quite as fit-and-forget as they suggested but a result non the less.

[Edited on 21-1-2006 by smart51]

Glad you got it sorted. Using 140 mains suggests that your exhaust is probably a bit restrictive in some way (manifold and/or can). If you get the urge for a bit more power you'll know what you need to improve.

Anyway, enjoy driving!

Paul

very glad you posted this topic. i am just fitting the dynojet kit and was not sure which hole the main air jet is. the manual is about as clear as mud.
I will set it up as per the instructions but at least i know to go to the 140 mains if necessary. Which position did you end up with the needle setting. 1 to 6... 1 being at the top. cheers Paul

6 is richest ie bottom groove as that lets more fuel in

Mine is currently set to the richest groove on the needles - that is with the needle as far out of the jet as it goes.

What I did was try a selection of grooves each with the 140 and 144 main jets. I drove at low engine speed, mid engine speed and high engine speed at low throttle, mid throttle and full throttle to see how it felt and sounded. I also tried rolling the throttle on and off plus snapping the throttle on and off.

It was terrible at some settings, marginal at others but there was only one setting where it was good at everything.

I think, to be fair to Dynojet, the kits are designed to be used on bikes, most of which will still run the standard airbox, and the mods might be a new air filter and exhaust and / or can. This is the sort of range of adjustment they are looking to cover. (Although I do agree the descriptions in the instructions could do with being a little clearer!)

We have a foam filter and a much better flowing exhaust system. My dynojet kit for the ZZR came with a range of needles and jets. I fitted the 155's to start with and the clips on the needles as instructed. As you found it was very rough and spluttered.

I spent a few days experimenting with needle position and jet sizes. Eventually settling on drilling the mains out to 205 and the needles right out with two washers under them. Now it goes like a rocket.

I am planning a trip down to Holeshot next month to get it set up properly on their rolling road, as I think that'll be the only way to ensure that it is right throughout the rev range.

Cheers

Mike

Mine has a TTS kit which they have developed especially for a BEC installation usinf a foam filter and a decent exhaust. It works a treat!

why do i need to block this hole ??

what difference will it make? is it worth doing?

why do i need to block this hole ??

what difference will it make? is it worth doing?

why do i need to block this hole ??

what difference will it make? is it worth doing?

Which hole? the idle air jet? On my car, blocking them makes the engine sound brokend and kills the power by a staggering amount. unblocking the holes restored normal service.

I used silicone sealant, that way it was easy to remove.

quote:

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Originally posted by Coose
Mine has a TTS kit which they have developed especially for a BEC installation usinf a foam filter and a decent exhaust. It works a treat!

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I have an All-Bikes spec 4-2-1 exhaust (as per Rich Miles' Striker) and have used his settings. They were: -

144 mains
Needles on 3rd notch
Air screws out 3.25 turns.

I've never had to touch it since, except for the occasional carb balancing (once a year)!