After having a few shortish rides on the new-to-me 'k' model nc30, I have a couplke of Q's......

What is the engine performance like through the rev range on a well set up bike with stock exhaust & filter?

Mine starts & runs like a peach but feels a little lacking in the 4500-6000 rpm area - from 6k the engine (intake) note changes & she pulls strong right up to 13ish, only had chance to redline it once & it felt like it ran out of revs at about 13,500???
The bike is still nice & tractable below 6k though, it's not like theres a big hole in the power delivery, basically, I'm interested whether I have much more to gain by dynoing or changing the jets/needles as documented on this site.
Obviously, I have no idea what has been done to the carbs previously but wouldn't want to start fiddling only to cock up fueling elsewhere in the rev range.

Handling;
It's not as poised/surefooted as I'd hoped, admittedly, I need to familiarise myself with the bike a little more as it's quite a change from my day to day hack of a 650 Transalp (great bikes , honestly ) but the front (early type) forks feel a little bouncy (underdamped) & the rear feels a little harsh in comparison.
Are the later cartrige forks much of an improvement over my damper rod items or the later shocks with the remote reservoir better than mine???

Re-reading this sounds like I'm having a bit of a whinge, I'm not, I love the bike to bits

Thoughts & opinions welcomed

Phil

you need to sort that flat spot out by reading cammos carby guide.

Your motor sounds typical of a bog stock setup, overhual your carbs and set them up as per cammo's guide.

Handling, your standard suspension is most likey shot to bits by now, a few pogo sticks would probably work better than what you have. Later forks and shocks are a improvment but again they need to be serviced and setup right to get the most from them.

The slides in the carb being drilled will help your mid range if they haven't been drilled already, the carbs could do with a check over in general I imagine as it sounds like you haven't delved into the bike yet.

The suspension is probably worn through age and need updating, there are quite a few upgrade options about, you just have to read what others have fitted and choose what becomes available.

Wow, thanks for the replies guys

True, I haven't had time to delve into the bike yet - hardly had time to ride it, never mind fiddle
I will run the bike through the summer & have a good check round carbs/valves & check/lube all bearings & change fluids in the winter.

I have had a quick look at the carb mod thread but not gone through the whole lot - to be honest if mine is typical of a stock early bike (very lean) I'm surprised how good it is.
I might be tempted to just lift the needle a bit, drill the slide & leave the mains - as it does run great & below 6k really isn't that bad If I can tweak & improve on that then great but wouldn't want it stinky rich either.
One more thing, the bike shop where I bought it said that it was running badly & someone had put the wrong jets in the wrong carbs (front to back) - an easy mistake as the Haynes info is incorrect. Apparently.....
Until I have a look we won't know though.

The forks do feel underdamped & will get a thorough strip & check in winter but to be fair the rear shock feels fresh with good damping - even on it's minimum setting

Cheers again, Phil

Oh yes, one more thing......

As others have said, it does sound typical of the performance of a stock early model bike. Standard bikes should have no trouble revving all the way to redline (14.5k rpm) in the first 5 gears. If it doesn't, something is amiss.

Performance can be much improved IMO by raising the needles and jetting correctly, gear it down a tooth on the front sprocket (from 15t to 14t) and it will be even better.

phil x wrote:the bike shop where I bought it said that it was running badly & someone had put the wrong jets in the wrong carbs (front to back) - an easy mistake as the Haynes info is incorrect. Apparently.....
Until I have a look we won't know though.

Sounds like the jets aren't the stock size then, early models had 110's all round which is very lean, so lean in fact that they often don't like to rev out (especially with the addition of an aftermarket can). Even stranger if the garage took the carbs off, opened them up, noticed the jets were the wrong way around and left them like that?

Regarding suspension, although they have a reputation for great handling, the suspension on many nc30's is just plain tired and won't be working well at all. Nothing that can't be fixed, some new fork springs, a replacement shock and grease up of all linkages will do it wonders. Some late model suzuki and honda shocks will drop in with some minor modifications, a good option if you don't want to spend hundreds on an aftermarket shock, not ideal but they'll perform better than a tired standard shock.

There's a wealth of information on the forum, enjoy your new ride!


p.s. The haynes doesn't list the wrong jet sizes for the carbs, you need to have a word with your mechanic. Or better yet - do the work yourself with the guidance of the forum and a haynes manual and save yourself the cash.

Cammo wrote:As others have said, it does sound typical of the performance of a stock early model bike. Standard bikes should have no trouble revving all the way to redline (14.5k rpm) in the first 5 gears. If it doesn't, something is amiss.

Performance can be much improved IMO by raising the needles and jetting correctly, gear it down a tooth on the front sprocket (from 15t to 14t) and it will be even better.

phil x wrote:the bike shop where I bought it said that it was running badly & someone had put the wrong jets in the wrong carbs (front to back) - an easy mistake as the Haynes info is incorrect. Apparently.....
Until I have a look we won't know though.

Sounds like the jets aren't the stock size then, early models had 110's all round which is very lean, so lean in fact that they often don't like to rev out (especially with the addition of an aftermarket can). Even stranger if the garage took the carbs off, opened them up, noticed the jets were the wrong way around and left them like that?

Regarding suspension, although they have a reputation for great handling, the suspension on many nc30's is just plain tired and won't be working well at all. Nothing that can't be fixed, some new fork springs, a replacement shock and grease up of all linkages will do it wonders. Some late model suzuki and honda shocks will drop in with some minor modifications, a good option if you don't want to spend hundreds on an aftermarket shock, not ideal but they'll perform better than a tired standard shock.

There's a wealth of information on the forum, enjoy your new ride!


p.s. The haynes doesn't list the wrong jet sizes for the carbs, you need to have a word with your mechanic. Or better yet - do the work yourself with the guidance of the forum and a haynes manual and save yourself the cash.

Cheers for that mate

Don't worry, I do everything on my own bikes (& friends') - wouldn't let a mechanic near them for all the tea in China
The stuff about the carbs needing bits swapping over sounded dubious but plausible but that was in the dealers before it went in the showroom.
The only way to know for sure is to open up the carbs & have a peek, like I say, I'll prob get the summer out of it & do a full job when the nights draw in again.

Are there any dyno graphs showing fuelling for stock & rejetted '30s???

Cheers, Phil

Dont wait for winter pal, its half a days job the first time you do it, then when you know what your doing rejetting takes 20 mins. Fuck riding my bike all summer with dodgy fueling, suspension costs £££'s so unless you got cash to burn then that can wait till winter but fueling costs very little just a bit of time.

^^^^

Just crack out the haynes manual and have your computer near by with Cammo's carb guide open and you cant go wrong.
As Drunkn Munky said, half a days job and its done, getting the carbs on and off can take some black magic sometimes but everyone has their own technique that works.

Little tip for getting the carbs in, use NC35 rubbers with a little red rubber grease and they will pretty much just fall in, yes i did say fall in. Try it guys, no levering, jumping on them or nothing.