My exups been jetted by p/owner

andy88 · Post by **andy88** » Mon Oct 03, 2016 4:12 pm

Hi all..jyst done a carb stripdown, and found its been jetted by previous owner(s)......originally stripped it down to clean and synch carbs to cure a carb pop on number 4 (sitting on bike, last pot on right) and slight bogging in 2nd at low revs to open throttle.
Carbs were grainy inside, and found fitted main jets 143's, and a flat stubby needle..ive Googled the needles and they look like a dynojet kit..anyway, needle was set at middle position. My plugs were fouled black aswell, so running rich.
Ive adjusted needle lower by 2 steps, making it leaner,and re set my fuel air mix to 2.5.(they were all over the place). Running k/n filter and a stubby..
Just took her back out and she is running a lot better, very very slight bogging in 2nd but no where near as bad..

Should i lower my needle to lowest setting for even leaner running, as she's still slightly hesitant when throttle is cranked open in 2nd..
If you wind her up normally,, she goes like a bloody rocket in overdrive

..

Any help or info is appreciated

Teego · Post by **Teego** » Mon Oct 03, 2016 5:14 pm

What is the state of your toobs? Any ovalling?

andy88 · Post by **andy88** » Mon Oct 03, 2016 5:31 pm

Hi...my toobs are round...no mishape, needles are clean,no scoring etc..exup valve stripped, greased and set,.... I know its been jetted, as there is now a cap in the air inlet as described in dynojet instructions..

But dont know if this is a dynojet kit etc.....the mains at 143 seem high....which would cause it to run rich..hence liwerin needle for leaner running.....

I hate it when these bikes are jetted and you then have to mess around wirh them...

Teego · Post by **Teego** » Mon Oct 03, 2016 7:25 pm

Get standard needles and toobs from Stig.

YAMAEXUP · Post by **YAMAEXUP** » Fri Nov 04, 2016 3:49 pm

I've got a DJ kit in my carbs together with blanking plugs in the air jet. If you're running individual or dual pods then the main jets you've got fitted sounds about right. The DJ factory suggestions state that if you're running a free flowing exhaust & pods then the Stage 3 kit is required. But if using the standard airbox & a K&N standard replacement filter, then the Stage 1 kit is to be used. But in either Stage 1 or 3, the DJ needle is utilised.

One thing that you don't say you've checked is the float height. I adjusted my ones & it made it a lot better.

Dynojet suggested using the middle 'C' clip position on the needles first, then choose either of the 2 largest main jets, then do a plug chop.

The good thing about Exup carbs is that the jets are easy to change when the carbs are in place