NC30 rings/piston kits

[motorbyclist]

nothing breaks either

[racefactory]

I have white smoke coming from my exhaust- it seems to be really thin... not like a typical ''smoke'', like water vapour almost. When the choke is on when i first start it there is quite a bit, when it idles there is nothing.. but when i rev it that white smoke/vapour comes out. It dissappears quickly, it doesnt linger round. It is pretty cold recently though! What's more is that I forget to check for it after the engine is warmed up, don't know if it's just a warm up thing.

I have heard this means either rings are worn or valve oil seal is worn or lastly, that the cylinder is worn. However the engine starts first time always and goes hard- sounds healthy to me. Or is it just because i have been riding 2 strokes and this is my first 4 stroke?

[motorbyclist]

it is infact water

one of the products of combustion is water vapour, and on cold mornings it condenses to steam which we can see. on a two stroke you wouldn't have noticed for all the blue stuff ybut it happens to them too

so you'll see it most when the bike (and exhaust) is cold, but any bike will do it on a cold day

[racefactory]

GREAT! Yeah, i guess i would have really noticed if it was proper smoke wouldn't i?

Love the sound of these v4's with the gear driven cams. These motors are bomb proof it seems- I have even found it really hard to come by any motor failure, seizure stories when searching the net.

I'd be most interested to hear a story here frm someone who's had the motor gone on them. As long as your so much as half arsed to keep the motor going I reckon the wheels will fall off these things before the motor pegs it!

By the way- as long as the bike is going hard and the valves are not making any sounds is it neccessary to check the valve clearances? Is it just when the valves start going tapety tapety you need to address it?

[racefactory]

Oh and how much did the top end cost you in the end?

I'd be interested to know where i can get rings, gasket, gudgeon bearing and maybe piston for a good deal.

Hey you said your VFR has been ''playing up for the last year'' in anothe thread - what probs did you have exactly?

Thanks.

[motorbyclist]

i didn't buy the parts in the end, as i don't need them and won't have the time til the summer

big problem with these honda bikes is that there's little or no aftermarket parts for them as there's no demand due to their amazing reliabilty; so if you do feel the need for parts you spend a small fortune on genuine honda bits

viffer hasn't been playing up, although i hear cyote's one has. i just have a habit of fixing stuff that isn't broken (or before it breaks)... only issues i've had are breaking/bending bits on power poles, finding the shitty workmanship from the last owner, a dead battery i've since replaced and a sticky brake piston for which i have a full set of seals to do my front calipers and master cylinder. so far i've thought i bent it, thought the clutch was going, thought tappets needed doing, became concerned for gearbox, worried about indicator relays, and thought i was burning oil, and all those were just me being paranoid - a bike abused this badly just shouldn't keep running

only ACTUAL problem i've had was vacuum hose on carby coming loose one day.

valve clearances don't need doing until they get tappety as even when out of tolerance there's alot of room to play with, but it never hurts to check as happy valves mean MOAR POWER

I've read a good post up from a novice mechanic who bought a dodgy bike and had to do a whole load of general maintenance to get her going properly... of course nothing was actually broken, it just needed clean carbs and new rotors... found it

[racefactory]

hey thanks man ill give it a read!

...........damn great article!!!

[motorbyclist]

i get the feeling you've come into 4 strokes with all these fears of things going wrong what with all these moving parts and the like...

i find the trick is not to overthink these things - more moving parts may mean more to replace and more to go wrong, but a 2 stroke relies on such a careful balance to operate, and anything outside the narrow operating range either stops it starting or siezes the thing.

always drives me nuts the way the two stroke crowd goes on about "the cost of a modern four stroke" and how 2 strokes are somehow more reliable.
sure there's many more moving parts but it's MUCH less temperamental, only needs one rebuild for every ten a 2 stroke has, won't seize because you didn't get the fuel mix quite right, and don't get two-stroke-itis or sulk.
good example being my yamaha motorcross bike: meant to be rebuilt every 150 hours, i've had her since 2006 and clocked up MANY times more than that without issue. neighbours/family all in the same boat with bombproof yamaha 4 strokes - occasional sparkplug changes and it's all sweet

not saying anything bad about 2 strokes here as they are very fun machines which can be very reliable, but don't believe the BS alot of 2 stroke riders spout forth about 4 strokes they usually have never owned

it's alot like bike shop salesmen raving on about 600 and trying to talk me out of my very happy position on my 400, which many a time has embarrased 600cc+ riders on a windy road

valve clearances don't need doing until they get tappety as even when out of tolerance there's alot of room to play with, but it never hurts to check as happy valves mean MOAR POWER

you egg motorb!

if the valve clearances close up it won't get tappitey at all

and if they close up far enough you'll develop some nasty issues beginning with power loss

whereas if you can hear them getting tappety, the valves are still closing properly so no damage being done, just power loss

[racefactory]

motorb you are right on- i think i may have come into 4 stroke thinking it could seize if i dont rebuild it etc. thanks man that's really given me another perspective on it.


are they any more likely to close up or open up?

so its better or worse that they open up or close up?

any other signs when they close up? What happens other than power loss when they close up?

Btw, where can i buy the device to sync my carbs? Or is worth taking it to a honda dealer for that? haynes says its probably best left to a dealer because the device is expensive.

I want to make a comple base of maintenance to start off with and then do my checks at intervals from this point so i'd like to get it all done- sync, air filter, oil, valves, fuel filters, rad fluid.

[lostinflyz]

you can find the balancer about on here. search for them and a few people have mentioned them.

alternatively you can make your own out of oil and piping. but only sync the carbs if the bike isn't running well as if you touch the carbs and they are good then they will from that moment on forever be terrible. Its a pain in the arse to do and a dealer will charge you a fortune, if they do it at all. The local honda dealer i took mine to cahrged me a hundred bucks and told me it was fucked and didnt do a thing. never really been back there since.

the vfr carbies are designed by people with eyes in thier toes and 10 jointed fingers and only work if they are happy.

[racefactory]

fuckin ell- ok mate thanks. Haynes doesnt make it out to be a big deal and say you should do every 12 000

[motorbyclist]

motorb you are right on- i think i may have come into 4 stroke thinking it could seize if i dont rebuild it etc. thanks man that's really given me another perspective on it.

these engines are literally bomb proof, and like most 4 strokes have a wide tolerance before anything actually goes wrong, and usually won't run if anything gets that badly neglected. the 4 carbies are a bit of a pain, but once right they usually stay right.

are they any more likely to close up or open up?

more likely to open up (educated guess)

so its better or worse that they open up or close up?

close up means the valves may not close properly, increased wear/heat and exhaust getting past vale damaging stuff. never ever heard of it getting to that stage without intervention

any other signs when they close up? What happens other than power loss when they close up?

dunno, only seen closed ones after you remove/reinstall the head and as such got them correct before running.

Btw, where can i buy the device to sync my carbs? Or is worth taking it to a honda dealer for that? haynes says its probably best left to a dealer because the device is expensive.

just make one, from what i hear they cost a small fortune when a board and clear pvc pipe do the same job

I want to make a comple base of maintenance to start off with and then do my checks at intervals from this point so i'd like to get it all done- sync, air filter, oil, valves, fuel filters, rad fluid.

does it need doing? get a haynes manual and you'll be set

just a few notes:

• filter is paper, so if blowing it out isn't good enough then be prepared to shell out for a genuine one, or replace with a homemade one.
• carbies are a pain to get at and work with, but reliable too - jetting should vary front to back due to rear cylinders running hotter than the front
• oil is easy, oil filter requires you to swing lower radiator forward and reach between two header pipes - and honda dealer sold me wrong sort once so check!
• fuel filter is a stalk intake inside the tank plus the one in the float valve
• radiator drain bolt on pump, lower left side behind fairings... i just pull off a supply hose as it's faster

but with these if it ain't broke don't fix it; the NC30 was not designed by honda's street division like the cbr and earlier vfr, is was designed by HRC for performance AND endurance. as such the engine is great mechanically, and relatively simple to do a complete rebuild for, BUT is a right cunt for any 'minor' jobs.

[motorbyclist]

fuckin ell- ok mate thanks. Haynes doesnt make it out to be a big deal and say you should do every 12 000

there's what they say you should do in a magical happy land of free time and unlimited funds, what you will get away with, and what you actually do in the real world. try to find a balance

i'm meant to rebuild my dirtbike every 150hrs - 1500 hours later she's still going hard, but some recent noises tell me i may as well do it now the cam chain is getting slack (or the tensioner is stuck, one or the other)

vfr carbies meant to be balanced every 12000? well i'm 3 times past that and no problems... wouldn't mind doing it though, just for the experience

[racefactory]

thanks a lot guys.

I've noticed even after warming up she is puffing just a little smoke... thin white smoke. Do you guys have that?

Man, the oil level is off of the dipstick but the oil light is still not showing. changing today.

Does that mean new rings most likely? How likely does it mean new cylinder?

By the way i took her out last night and i was revving her on my driveway before hand... first time i went up the road i got misfires i think.. is that the plugs not being hot enough and getting fouled by fuel?

Motor goes really hard though.. no noises and taps and power all through the rpm range.

[racefactory]

Also, how much can i expect to pay someone for a valve clearance job? And where abouts would do that?

Alternatively, if anyone could show me for a first time that would be absolutely awesome! Is anyone interested?

I have haynes manual but it seems a bit daunting a...