Where do you buy carb jets from?

[lloyd_christmas]

I am going to rejet my carbs on my 1999 curvy as it has a full micron system but runs like crap.


Where can i buy jets?

Does anyone have any first guesses as to what sizes i need?


Cheers

[yorkie_chris]

Allens performance.

What mods? Everything else healthy?

[lloyd_christmas]

The bike has never ran that great while i have had it, it tends to be a bit hesitant when the throttle is first opened so i am guessing it was never rejetted/is poorly jetted for the micron system.

The airfilter is standard as far as i know, although i will take a look, plugs should be okay but i will have a look when i have the airbox off. I have balanced the carbs relatively recently.

[yorkie_chris]

Try 3rd gear, whack the throttle wide open at 6k rpm, see if it hesitates.

[Dave20046]

Try 3rd gear, whack the throttle wide open at 6k rpm, see if it hesitates.
soz to derail but mine does in 1st and 2nd - I put it down to the restrictor kit. was I wrong?

[yorkie_chris]

If it's very lean it will be horrible around there in all gears. Hard to say, but the leo system you have is a much better one than stock.

[Dave20046]

If it's very lean it will be horrible around there in all gears. Hard to say, but the leo system you have is a much better one than stock.
I'll take more notice. Really can't be arsed to rejet it though lol, meh I'll do it when I balance them.

[yorkie_chris]

Haha rejet is wayyy more effort than a balance.

Tell you what I'll swap your pidgeon $hit welded leo for a nice condition stock set of pipes :-P

[Dave20046]

Haha rejet is wayyy more effort than a balance.

Tell you what I'll swap your pidgeon $hit welded leo for a nice condition stock set of pipes :-P
I know lol you've got to overcome the cheesey bolt masters of the float bowl. But I'll be in that general area I suppose.

haha **** off :P It's a decent exhaust keeping it til I sell the bike. I've got a stock set aswell anyway. Getting a new downpipe made when I can be arsed.

[yorkie_chris]

You need to take carbs off which is a bit of a ball ache. Speaking of, just check the carbs are seated right and the clamps are snug before you start rejetting.

Get hold of some stainless screws to replace the stockers with, and an impact driver to get old ones out if it does need a rejet.

If you want it all sorting then your best bet is a trip up here to beowulf, they can make new pipes etc. and also have a dynapro dyno there which is IIRC £20 for an AF run or £35/hr for tuning.

[Dave20046]

Cheers (that's useful to me and lloyd)
Yeah checked and got all that, probably is the jetting. Don't look forward to removeing the carbs, hoses cables and all though. might be optimistic and double check with the plugs before píssing about.
No point dynoing a 33bhp really is there - would just need to do it again when I take the washers out.

[yorkie_chris]

Derestrict it, check it's fuelling ok, then restrict it again. PITA I know but it's the only way I could get mine right!

[lloyd_christmas]

Try 3rd gear, whack the throttle wide open at 6k rpm, see if it hesitates.


It does a little bit, but it is far worse when slightly opening the throttle at low revs.

[yorkie_chris]

Is it worse when hot or cold? It could be lean in the mids rather than up top.

A dyno is the easiest way unless you are prepared for a lot of faffing about

[lloyd_christmas]

Is it worse when hot or cold? It could be lean in the mids rather than up top.

A dyno is the easiest way unless you are prepared for a lot of faffing about



Deffo worse when cold.



Power also dies off at high revs. quicker than it used to though, although i have a feeling i may have a slight airleak.

I am going to have a look at it now, check the plugs, check for airleaks and balance the carbs again.

[lloyd_christmas]

Okay, it looks like i had a slight airleak around the carb-airbox joint. I have now rectified this and the bike feels better.



I would still like to fiddle with the jetting though, a performance gain would be nice and i will surely learn something along the way.

Over the course of the summer, i would like to do the 'stage 2' cam mod, and fit a different air filter.

I would presumably be best doing these mods first and then sort the carbs afterwards?

I would much prefer to fiddle with everything myself rather than pay for someone to tune it but Chris, you say the easiest way is to get a dynorun?

Will dyno places be happy to let me just pay for a dyno run without having any tuning done there?

Is this a reasonable order of events;

acquire filter and cams
fit filter and cams
adjust jetting etc. by best guess
get dyno run
readjust jetting etc. according to dyno printout

[yorkie_chris]

What's the point of changing jets now when it's jetted right? You'll just end up back where you started...

Changing jets adds no power, it's simply to allow breathing mods to work. Airflow = power you just need to add the correct amount of fuel.


Yes that seems like the best way to do it to me.

I have BMC race RS filter and micron with stubby can. 165 mikuni main jets seem alright.

What is stage 2 cam mod? Pointy intake cam swap you mean?

[lloyd_christmas]

What's the point of changing jets now when it's jetted right? You'll just end up back where you started...

Changing jets adds no power, it's simply to allow breathing mods to work. Airflow = power you just need to add the correct amount of fuel.


Yes that seems like the best way to do it to me.

I have BMC race RS filter and micron with stubby can. 165 mikuni main jets seem alright.

What is stage 2 cam mod? Pointy intake cam swap you mean?


Pointy intake, and then switch the curvy intakes onto the exhaust. Is that right?


Thanks