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struggling to start newly acquired bike

Posted: Tue Oct 11, 2011 9:27 pm
by psalliss
Just bought the below bike off ebay for £250. Its been sat for 10 years in a working garage but was started several years ago.

http://www.ebay.co.uk/itm/120789070216? ... 500wt_1219

Have stripped the bike down abit with all fairings off and have had tank off and air box removed and calpers off. Emptied the tank out and drained the float bowls. on checking the carbs the pistons appear ok and moved freely as does the throttle cable and the choke cable. spark plugs have been checked for spark and all spark ok. also put brand new battery on and fully charged it using optimate.

tried to start the bike and starter motor spins fine but the bike wont quite start. mate bought a nc24 in worse condition a week ago and got it going by spraying carb cleaner into the carbs and eventually got it going.
i have swopped the spark plugs with some spares that my mate had which appear ok and like i saw are sparking fine.
the bike almost caught several times when mate was sucking the vacumm tube. (not sure why he was sucking but he was adament it was how he got his going. lol)

Anyone got any suggestion as too how to get it going. debating putting new plugs in, but dont want to spend too much on the bike unless i have too. and spraying carb cleaner directly into the carbs and then trying to start it again.

Re: struggling to start newly acquired bike

Posted: Tue Oct 11, 2011 10:42 pm
by magg
Vacuum hose has to be connected at engine and tank. No vacuum, no fuel flow. Doubt sucking on the hose is going to be the best method to get fuel flowing into the carbs.

Re: struggling to start newly acquired bike

Posted: Tue Oct 11, 2011 11:35 pm
by psalliss
Cheers mate thought the same myself. Any suggestions on hOw to get it going

Re: struggling to start newly acquired bike

Posted: Wed Oct 12, 2011 2:27 am
by magg
To check the vacuum operated fuel tap works, connect the vacuum hose between the fuel tap and engine ( make sure the vacuum hose has no holes or cracks), connect a hose from the tank tap outlet into a suitable container. With kill switch ON, turn on fuel tap and press the starter button. Fuel should flow.

Re: struggling to start newly acquired bike

Posted: Wed Oct 12, 2011 11:42 am
by psalliss
Thanks mate. Pretty sure fuel is getting through as checked the float bowls and they had fresh fuel in. Thinking the spark plugs aren't much cop and the carbs need cleaning with carb cleaner. Does that sound about right?

Re: struggling to start newly acquired bike

Posted: Wed Oct 12, 2011 12:47 pm
by arsey30
I would rather do the fuel flow test with the kill switch OFF.

Usual problem when left standing is dirty/gummed up pilot jets and circuit.
Strip and clean all jets and airways.

Re: struggling to start newly acquired bike

Posted: Wed Oct 12, 2011 1:38 pm
by Neosophist
Although the bike doesnt start at present, it will only require the carbs cleaning and a fresh battery.
Did you strip and fully clean carbs?

NC24 plugs are a lot more robust than 30 plugs so give them a wire-wool cleaning.

Check / set float heights, clean all jets and passageways.. verify right needles, jets and emulsion tubes are in right carbs and re-fit.

New battery is a must (fully test the electrical system when it's running as these are a weak point)

With the carbs stripped and cleand and vaccum hose attached.

5 seconds of cranking with full choke and NO throttle at all until it fires up then rev it gently. Rest for 2 mins between cranks... make sure battery is fully charged and it will take a minute or two for fuel to fill the carbs (vaccumn tap)

Wouldn't even bother trying to get it running until I had

1. cleaned / overhualed carbs
2. good new fully charged battery
3. verified fuel tap / vac hose is working

Re: struggling to start newly acquired bike

Posted: Wed Oct 12, 2011 2:37 pm
by psalliss
thanks mate for the advice. yes brand new fully charged battery has been fitted. i didnt strip the carbs and clean them as to be honest although ive had bikes for years they have always been modern stuff and never fiddled with them and i dont really know how to clean the carbs or what it entails and what parts are what.

pretty sure vac hose is working as is fuel tap. i think. lol

Re: struggling to start newly acquired bike

Posted: Wed Oct 12, 2011 9:13 pm
by psalliss
hurrah bike started first time today without doing any of the above but wouldnt idle. im presuming carbs are still a bit gunked up

Re: struggling to start newly acquired bike

Posted: Thu Oct 13, 2011 4:04 pm
by Neosophist
psalliss wrote:thanks mate for the advice. yes brand new fully charged battery has been fitted. i didnt strip the carbs and clean them as to be honest although ive had bikes for years they have always been modern stuff and never fiddled with them and i dont really know how to clean the carbs or what it entails and what parts are what.

pretty sure vac hose is working as is fuel tap. i think. lol
Cammo has a carb guide that is stickied at the start of this section of the forum.

Have a read through it!

With NC24 carbs just do not drill the throttle slides or shim the needles.

Float heights are 6.8mm.

Ensure jets and emulsion tubes are in right carbs, often get mixed up.

Should be 115's all around or if it's and early bike will be 112/115.

The emulsion tubes, the 5 holes go in the rear.. 4 holes in the front.

It will all make sense after reading cammo's guide.. a good full clean will have them running great.

After thats done and while there off, chekc and set valve clearnecnes (can't stress importance of good clearnaces) there are no shims to replace on this engine just locknut adjusters so wont cost money to do.

finally re-fit carbs, fire it up and balance the carbs.