She lives! But still having problems :s

[fatkat]

Morning all,

Firstly, nice job on the new forum! Looks, and feels, much cleaner.

Just a quick refresher, I have a 1996 NC35 which I have been slowly bringing back to life after a long period of neglect in the shed. To date:

New spark plugs
New air filter
New oil and filter
New battery
New chain and sprockets
Cleaned carbs and new gaskets o-rings
HRC carb slider springs
Overhauled calipers, new pads, new fluid
New coolant, with system flush
New fork oil, and seals
New clutch cable
New fuel tap
Various cosmetic changes

Initially, I had a hard time getting it started, and after a little investigating (and getting petrol absolutely everwhere) I discovered the fuel tap was borked, the diaphragm wasn't sealing properly, no vacuum was forming, and thus no fuel was being pulled through. Changed the fuel tap, it started for a few seconds then died, then failed to start at all despite all my persuading.

I removed the spark plugs, the front and rear right hand side plugs were slightly carbon fouled, and had a fair bit of oil on them, cleaned them up with some tissue and a wire brush, swapped them with the left hand side ones and it fired up. Woohoo, happy days.

After a little messing around with the idle speed and the choke, I finally got it to idle with no choke without dieing. Now I'm fairly pleased that it actually starts, but it runs like a one legged badger. It's rough, and the idle fluctuates a fair bit. On blipping the throttle the return to idle is taking longer, almost as if it is sticking. I cleaned up all the gunk from the throttle controls on the carbs, so I don't think it is this that's causing the "stiff" return. There was a fair amount of white-ish smoke from the exhaust when it first fired up, and when I blipped the throttle. Also, it sounds rough too; possibly running on two cylinders? There is a slight flat spot when blipping around 5k.

The one thing I know I haven't done is check the valve clearances, could this be an issue? Or have I borked the carbs (I didn't check the float heights either, doh) when I cleaned them? Could this at all be related to an electrical issue? That would be something that's beyong my realm of "I'll give it a go" (and yes, the speedo is plugged in and all the dials are working).

Any thoughts people before hand it over to my local garage to have a look at?

Cheers,

Jason.

[viper_biker]

If you are mechanically minded I'd take the carbs back off and balance them as well as do the valve clearances. As for the sticky throttle, make sure the cables are routed correctly as this can cause a slow returning throttle.

[wullvfr]

2nd that,balance carbs and make sure valve clearances are ok......
its maybe worth while taking the throttle cables off and giving them a lube,double check the grip hasnt slid down slightly onto the bar end coz that sometimes happens with mine and it doesnt snap shut as fast as it usually does.

[Sam]

I see your in finchley, me too, do you take your bike to Bob Thomas?

[fatkat]

I've had it serviced by them in the past, but when I spoke to them recently they said they didn't do imports

[Cammo]

I've had it serviced by them in the past, but when I spoke to them recently they said they didn't do imports

Tell them it's a UK nc30....


It sounds as though the carbs aren't right. Take them off again and check the float heights and also the idle screws (check Haynes for the spec). Definitely a balance also, the quick (drill bit) method is easy once you have the carbs off.

You should be using full choke to start it from cold, and it should die if the engine is cold and you shut the choke off. It will take a good few minutes to warm up to when you can shut off the choke. Let it warm up at full choke and don't be tempted to use the throttle, often the bike will die. Once warm, set the idle to what the Haynes says. In my experience the choke is needed either full on or full off, no in between.

[fatkat]

There is a problem with the engine, so I've had enough and decided to try and sell the lot. See the for sale page for more details.