Under hard acceleration my bike is bogging down @ 3000rpm until I ease of the throttle, only happens if I'm accelerating hard from standstill. Is this too rich or too lean ?
Will adjusting the AS effect this? Is in lean out rich or the other way round?
3000rpm. You're trying to accelerate hard from 3000rpm? :O Not going to happen!
Adjusting the AS will not affect this at all if you are WOT. That's the main that's too rich, for those revs. When you back off, you're mainly running on the needle. The AS only affects very small throttle openings, up to 1/4 open. Jetting depends on throttle openings, not engine revs! I am not saying you should go smaller on your mains to compensate, unless it's rich throughout the rev range.
The answer is, if you're trying to get away quickly, then you should not be trying to accelerate hard from such low revs on a two stroke especially.
If you find the same sort of behaviour throughout the rev range (i.e backing off at 8,000rpm and at 11,000 causes the bike to speed up) then it is likely you need to run a smaller main, as the bike is too rich, in that case.
Cheers guys, so if this is user error - whats the best way to get a 2 stroke off the line quickly, I've tried revving it high feathering the clutch and re- revving pretty hard and popping the clutch - found out it pops up pretty quickly like that
My technique that got it bogging down was revving to @ 6500 - 7500rpm then dumping the clutch and twist on the throttle to WOT ... ( probably not very technical but worked on the CBR)
Found that mine was a bit slow off the line, too. I could rev it up, but as I let the clutch out the revs would drop and it would bog if I wasn't enthusiastic!
I got it a lot better, right up until the oil line came off and it seized
What I recommend doing is checking your power valves are set as per the HRC method outlined on the tuning part of the site. That should make things a lot better if it is out, don't rely on the marks on the butterflies that the power valve cables attach to. That's where I'd start.
I did that, and tweaked with my jetting a bit and the bike was awesome! Though, start there before you go fiddling with jetting, and if you do jet, be very careful. Do make sure those damn oil lines don't slip off... I'm going to use better clamps (and a LOT more caution) despite what Andy says.
Apart from that, sounds like a typical NSR, rev it, let the clutch out, wheel stand. It's a blast.
The NSR is a 'race bike' with a high first gear, desinged to be great on the track. It's really not great for fast get-aways from a standstill no matter what you do with the jetting. I always lost places at the start of a race as I never mastered the art - maybe Fontyyy has some advice?
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NSAAGGHHH wrote:Cheers guys, so if this is user error - whats the best way to get a 2 stroke off the line quickly, I've tried revving it high feathering the clutch and re- revving pretty hard and popping the clutch - found out it pops up pretty quickly like that
Do that, but if it pops up, feather it some more till it's all the way out.
But really, it's a closet race bike, it's not designed for drag racing.
You are still going to be quicker off the line than most snoozers in their cages. And its only a problem till you get to the twisties, where you can really let her sing!
True!! But getting my ass handed to me by my wife, until I get it moving ain't cool haha .. Im happy with it, tried a few today an realized the best way is just smooth acceleration from the line and enjoy the top end crazy acceleration, keeping it on the boil when upshifting is a lot of fun
To be fair an NSR should be able to take full throttle from 3k. On the dyno we test them from 4k upwards but they do take it well.
If it wont have a look at the reeds as well as the jetting. Alot of these bikes are 20 years old and have never had a new set of reed valves in their lives. _________________ If I have to take the carbs off once more...
NSAAGGHHH wrote:whats the best way to get a 2 stroke off the line quickly,
Rev it to about 11000 and let the clutch out as fast as you can without really wheelieing.
A mechanical lack of sympathy is required for fast launches. _________________ Please do not PM me technical questions, if you can't find it on the Forum start a thread
anonymous.shyster wrote:Umm, what does your wife ride?
CBR250RR, in fairness it is very well setup and very very easy to launch hard and revs to 19000rpm. The NSR pulls it back in pretty quickly but it's already a fair way behind by the time I can get to WOT.
I've ordered unifilter pod filters, chasing a jet kit (anyone know a good place online to order one?) and the reeds sounds like a good idea, are all carbon reeds the same? As I've seen various ones on eGay with big price variations.
silly Q the AS .. The recommended 1.5 turns out - to lean would I turn in or turn out?
My screw was already at 1.75 turns out and I'm wondering if this may be the reason but don't want to adjust it and run it without knowing which way to turn it.
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