carb rejetting

[seanycozzie16v]

right so now i have all carb issues sorted out and its running quite sweet i find towards the top end in 3rd or 4th gear the engine starts to struggle a bit and the revs will drop slightly. so i want to make a little more power towards the top end so its carb rejetting time! the question is what size of jets shall i put in the thing? currently the pilot jet is #20 and the main jet is 102.5. also anyone got any tips to make this bike perform a bit better? its quite sluggish taking off in 1st too sadly. and yes i know its only a 125 vtwin so its not gonna win any speed records but i'd like just a little more power so i can do 60mph on the carriageways. atm i can only get 54mph out of it

[Stu]

getting a bike to go faster is not a case of just sticking different jets in!

you need to know how it is fuelling before up or down jetting

you may only need to adjust the needle hight for all you know

getting it wrong could cause you to blow the motor!

Ideally you need to get it on a dyno

but if you really dont want to do that then you need to figure out how it is running some how and if you are prepared to trial and error then go for it and buy a load jets of different sizes and try them

[Tango]

Checking the spark plug colour will give you an idea on whether it's running rich or not.......

As Stu says, raising or lowering the needle height could help too......

[seanycozzie16v]

its running quite good across the range just towards top end its a bit sluggish. plugs show a good sign of running correctly and there is no coughs or splutters on full open throttle. plugs are a tanish colour with no white spots which indicates its not running lean. maybe even the next size up which is a 105.0 main jet may help a little on wot situations?

[seanycozzie16v]

another thing to mention i added stainless steel wool to the exhausts to quiten them down for mot. i assume that too much would cause too much back pressure and therefore cause a loss of power towards the top end

[Mr Fro]

Have a look at This. It'll give you an idea how to go about fiddling your carbs (you want the low rpm version I think). You're lucky insofar as you've only got one carb to play about with.

I've used this guide and got reasonably close to ideal conditions but you really can't beat a dyno run.

[seanycozzie16v]

these little vtwins rev to 11000rpm iirc so would that be high rpm?

[Mr Fro]

11k on a diddy V? Yeah, that'll be the high one then.

[Lumor_uk]

How heavy are you? That's pretty slow for a v twin. On my 125s they've been faster than most cars (not racing) up to 45mph and all have got up past 60 to 70 eventually

[Hoggs]

Whilst I admit I am lardy, I always found our intruder was quite slow at the ole acceleration

[seanycozzie16v]

I'm quite a lardy fella mate. 18 stone. Had the bike doing 65 on the dual carriageway yesterday. Would happily sit at 60 but I really had to push it to do 70

[Lumor_uk]

You need a bigger bike, 13 stone here.

[seanycozzie16v]

I'm surprised I near got it up to 70! I'm rarely on dual carriageways anyway