NC29 Wont fire - any help?

gullarm · Post by **gullarm** » Wed Apr 27, 2011 8:39 pm

Im having major problems getting my nc29 to fire.

To cut a long story short bought a non runner a few weeks ago, guy said battery was flat but would run good as he had i running 3 months ago -blah blah blah.

Needs some work on the plastics/tank and forks seals are gone but then what 20 year old bike doesnt need work.

Now I cant get it to go - at all.....

I wanted to make sure it ran before stripping it.

Turns over nice and fast
All electrics workings except for left hand indicators

So far I have checked.........................

Battery - totally flat - jumping the bike from my car
Coils - all within ohm tolerance and sparking
HT leads - tested number 1 with a nail in it - again sparking ok
Fuel pump - pumping fuel - have also bypassed and now gravity feeding into carbs
Neutral switch - removed and cleaned - and also tested on bike
Removed air box and air filter
Kill switch - tested to where it joins the red connector on left hand side - all ok
Tested the pulse generator coil as per haynes manual - all ok
Occasional backfire from exhaust on turnover - one nearly deafend me

The only thing I havent tried is removing the plugs as I dont have a plug spanner. And they are a pain.

Any help....

Also how hard is it replace the forks seals?

Please.

Post by **hallsie** » Wed Apr 27, 2011 9:05 pm

Kill switch can be an arse causing it not to start but if it's sparking and fuel is getting through ( new fuel I presume ) then possibly plugs , I had issues with mine that are similar and I checked and double checked everything and it still turned out to be the neutral switch playing up !

gullarm · Post by **gullarm** » Wed Apr 27, 2011 9:19 pm

The neutral switch was my last attempt.

I removed it, oil shot out- make sure it was moving in and out - all ok.

Tested in situ with a meter - with wire removed - connection to gound in Neutral - open circuit in 1st or 2nd.

Put wire back on and havent touched gear lever to make sure it still in correct place.

I will trace the cable to make sure its working and may try and bypass it tommorow, just ground the cable to the chasis. I cant understand how the neutral light can be on but the bike thinks its still in gear it doesnt make any sense.

Plugs are my next roll of the die, which Im not looking forward to.

micklewright · Post by **micklewright** » Wed Apr 27, 2011 9:39 pm

Just a word on these CBR motors, I have had the experience of two of the inline 4 NC23 and NC29's over the years, out of the dozens of bikes I have owned or worked on, fault finding on these has got to be the biggest nightmare I have ever had.

My current NC23 bike was ridden to me from 50 miles away and ran as sweet as could be. It was laid up for a month at most and would NOT start, every inspection came up without fault...

I usually clean up plugs to at least get some running out of an engine and then go out and buy new, the honda's were no exception, did it work....No! Went and got a set of new plugs (to the standard lower performance recommendation in the haynes) and off she ran!

Have not looked back, both occassions new plugs was all it took and Im tracking said NC23 this year without a missed beat as yet!

Good luck!

Post by **Cammo** » Thu Apr 28, 2011 2:03 am

micklewright wrote:Went and got a set of new plugs (to the standard lower performance recommendation in the haynes) and off she ran!

+1 What Mickle said ^

Sounds like you've flooded the plugs, pull one out and see if it's wet...

gullarm · Post by **gullarm** » Thu Apr 28, 2011 12:39 pm

Right got the plugs out - covered in petrol and very wet.

Got some new plugs and a spanner - had to modify it to get it in.

Had to remove the coils so decided to test HT leads, have tested the coils before. But not the leads.

Cy1 was firing with a spark last night.

Anyway.......

Cyl 1 HT lead ok - 5k resistance ( is this right? )
Cyl 2 HT lead - open circuit!!!!!!
Cyl 3 HT lead 50k Resistance ( hmmm too high? )
Cyl 4 HT lead 5K resistance

Pulled the cables out and measured the actual caps. The cables are ok the 2 caps are the problem.

Been to back to my local bike shop - very expensive £15 each from HONDA and he would have to order in.

There are a few on ebay is there an alternative type I can use? From a different bike.

Or cheaper place to get them from.

leopard_pagan · Post by **leopard_pagan** » Fri Apr 29, 2011 10:38 am

"very expensive £15 each from HONDA"
>MUG!!! NGK are the standard and can be bought from anywhere who sells am.. car shops inc

take an old plug to a CAR shop and buy them over the counter £7-10 each tops!

gullarm · Post by **gullarm** » Fri Apr 29, 2011 2:39 pm

The dude in the bike shop has the NGK ones - but they dont have the seal at the top to keep out the water/dirt etc

So Im looking at some on ebay.

Loads of things to do on the bike so I can wait for the HT leads for another week or so.

Yesteday and today I took the whole front end off.

Replaced headstock bearings this morn and had shocks rebuilt.

Now to put it all back together.

Its going better than I could have thought. Though I do have this web site to thank and you tube as well.

leopard_pagan · Post by **leopard_pagan** » Fri Apr 29, 2011 9:55 pm

seal? new one on me, never seen a "seal" in the 9 odd years of owning a NC29 with several plug changes.. and i aint gonna type what i think of your bike shop guy!

my bog standard NGK plugs only come with a metal washer thing that you cant get off a plug on the threaded end. ALL spark plugs i have seen have one. kinda like a crush washer.
HT leads ARE the "seal" that keeps the crap out of the plug recesses. the HT leads have a kinda umbrella that pushes on to each plug to seal it in.

NC29 HT leads look the same as pictured, the top "cap" seals the plugs in.

gullarm · Post by **gullarm** » Sat Apr 30, 2011 12:04 pm

When I said seal i meant the lip at the top.

Like in your photos - the shop can supply leads but not the correct ones so if any water got into the tube where the plug sit it could fill up with water and not run.

Unlikely I know but it could happen.

Id rather try and get the real thing from ebay or even honda than get stuck on a road after a heavy ride in the rain.