My NC30 Woes

[Badgerboy]

Picked up my bike up Saturday, there were a few faults with it, but I used those to get the price down. I've fixed the electrical problems, but am having problems starting it.

If the bike is cold in the morning, I can normally start it quite easily with the choke. After that, its pretty hard to get going again. I've pulled the sparkplugs and they are usually soaked, so I'm assuming the bike is flooding due to overfuelling problems as causing the restart problems. If I pull all the plugs and clean them, the bike is normally happy to start again.

I'm going to try and take it to a garage on Thursday for a service. Can you guys arm me with some information on the likely cause of the problems? In addition, how much work is involved in a carb and shim service? (They probably need doing!)

Other than that, the 3 hours I had on the bike were good fun! It's a white and black K-Conversion with what looks to be uprated brakes front and back and a Yoshimura can. (Bloody loud!)

Just wished the bloody thing worked!

[Cammo]

The proper way to start them when cold is FULL choke, NO throttle. Sometimes even a small twist of the throttle is enough for it to stall due to flooding or stop it starting.

When it's warm you shouldn't need choke, but don't give it much throttle.


The plugs are expensive, you'll soon be familiar with what it needs to start.

[Badgerboy]

It'll happily start in the morning with the usual startup sequence, but once running it'll happily drown the plugs in fuel so restarts are a bit tricky!

I am planning to change the plugs tomorrow, but trying to figure out why the bike is overfueling in the first place.

[wullvfr]

hello-

usual suspects for flooding is poor starting technique but as you have stated that it starts great in the morning with full choke no throttle then that is pretty much ruled out.

it could one of a few things..

a problem with the floats,either too high,float needle valve broken or stuck open.or something like dirt etc causing the valve to seat incorrectly.

another issue could be jet sizes,if they were too big allowing way to much fuel into the cylinders but i highly doubt that.

do you get any backfiring at all?????


william

[Cammo]

Pilot screw settings out can also cause the plugs to foul at idle.

[CMSMJ1]

A choke that does not close is what my 20p is on. It starts fine from cold..unlike most NCs..lol! Then drowns itself..naughty moto!!

[wullvfr]

A choke that does not close is what my 20p is on. It starts fine from cold..unlike most NCs..lol! Then drowns itself..naughty moto!!

if this is the case then the bike will idle higher than normal...does this happen?

with the choke fully open the revs usually sit between 3500-5500rpm.when the bike is warmed up and no choke it should idle @1300rpm -+100rpm


william

[Badgerboy]

Well I changed the sparkplugs this afternoon, and she fired straight up. With the choke fully out, the revs rose to about 3k, and sat there for a little while. After a few mins however the revs started to drop toward 1k and a little spluttering could be heard. Had a friend tweak the throttle for me to keep it going while I got myself sorted and took it for ride.

Once fully warmed up and choke closed, if I park up the engine will drop to around 1k for a few seconds, and then cut out. I also noticed quite a few flat spots through the rev range, and it didn't really want to rev cleanly over 8k.

I personally think the carbs are filthy and out of balance, so I will try to get them looked at tomorrow. Hopefully the chap will find the overfuelling problem as well, and sort out the idle issues! Then finally we are good to go!

Thanks for the responses guys.

[wullvfr]

I personally think the carbs are filthy and out of balance

sounds about right,definately carb related.




william