NC30 wont start??

Post by **Cal Walker** » Fri Jul 31, 2015 8:57 am

Hi guys

Just been to go and have a morning ride and started my NC up, fired up on the first turn with a little bit of choke. Started fine and all of a sudden the revs started to get lower and lower and eventually it cut out. I'm finding this really weird as last weekend I took it out and it ran absolutely fine!

Been trying to start it for a while now and I cant get it going, last thing I wan to do is flood the thing. Tried starting it with various stages of choke, with the fuel tap in "ON" and "RES" and still nothing. It sounds like it wants to start but I get nothing. Checked also the tank vent pipe and that isn't blocked.

If anybdsy can help me!?

Kind regards....Cal

vfrman · Post by **vfrman** » Fri Jul 31, 2015 1:46 pm

Hmmm.. I'd crack open one of the float drains to see if there is any fuel coming out. If the battery is good and the bike is getting spark, it is fuel. Perhaps the vacuum line for the fuel tap is split or damaged (assuming the tap isn't HRC modded).

Post by **Cal Walker** » Fri Jul 31, 2015 3:07 pm

Cheers for the reply mate. That's what I thought so I put some fresh fuel in and still no joy. I haven't had chance to check for a spark or the float bowls as of yet but im pretty sure that all the Sparks are there.

I did check the vacuum pipe to make sure it wasn't trapped but I'll take the tank off to make sure it hasn't split. It was all running perfectly fine last weekend, can't see how much could of gone wrong in a week with it sat. It was its first proper run out last weekend though due to work.

Any idea how I check if my fuel tap has been modified? I don't think it has but again I'll check.

All comments welcome.

Many thanks....Cal

vfrman · Post by **vfrman** » Fri Jul 31, 2015 4:29 pm

The easiest way is to take the fuel line off that goes to the carbs and turn the tap from off to on or reserve. If fuel comes out, the HRC mod was done. The mod basically removes the spring and I think diaphragm from the tap so you don't need vacuum to open the tap. This is done on race bikes that are prone to high rpm fuel starvation.

Post by **Cal Walker** » Sun Aug 02, 2015 7:17 pm

Right been out in the garage this afternoon. Tried to start it quickly, yet again no joy.

Took the tank off and the main pipe was full of fuel on removal. Opened the fuel tap to check for the HRC mod and it hasn't been modified, no fuel came out. Checked the vacuum pipe and all was good there, no splits tears or blockages. Checked the main fuel pipe also and all was good as well.

Pulled and cleaned the two rear cylinder spark plugs and checked them both for spark, they both were getting spark no problem at all and the clearances were within range.

I wasn't able to get to the two front plugs because of space and I also wasn't able to check the float bowls as the drain screws are obscured when in the frame.

Put the tank back on to see if it would pull fuel through when turning it over. I pushed the button for a good 10 secs and then popped the main pipe back off the tank. There was traces of fuel as the pipe inner was wet, but it wasn't full of fuel.

Could this mean that my fuel tap isn't working correctly? I'm really needing help with this guys as I cant find the problem as to why my NC wont start!!??

Any help is much appreciated.

Kind regards....Cal

Post by **Kenthammer** » Mon Aug 03, 2015 8:26 am

Mate

Invest in one of these, not only will it take your tank, filter and tap out of the equation, you get the tank out of the way, so you can access components with ease and secondly you can actually see the fuel level and how much it changes by when you fill the carbs etc. Just suspend it above the bike from the garage roof or wherever

http://www.amazon.co.uk/gp/product/B004 ... ge_o09_s00

Post by **willandrip** » Mon Aug 03, 2015 10:48 am

^ The linked auxillary tank is more than sufficient if you have something to hang it from.

If you need to work outside with nothing to hang it from, something like this can be stood on a window cill or similar.

It's only a few quid more and good quality.

http://www.ebay.co.uk/itm/Motorcycle-JM ... 20fdf6fda6

If your skint......an old "Fairy" round type washing up bottle,(ones with the flared end nozzle ) can be used.
I still often use the above......you can squeeze them and apply a bit pressure to a fuel system similar to that supplied by an electric pump (5psi) to diagnose pinhole leaks.

vfrman · Post by **vfrman** » Mon Aug 03, 2015 3:29 pm

You can test the tap with the tank off the bike by applying a vacuum and then turning on the tap. Fuel should flow.

It couldn't hurt to pull the fuel tap off the tank and check out the filters as well.

Post by **Cal Walker** » Mon Aug 03, 2015 7:40 pm

Cheers for all the replies guys.

Funny enough, I ordered a auxiliary fuel tank last night to test without having to include the tank, hopefully it will let me know if there's an issue with my fuel tap as well.

Right if I suck on the vacuum line then open the tap, should fuel then flow correct?

Again any other issues as to why it wont start are much appreciated.

Many thanks.....Cal

Post by **willandrip** » Mon Aug 03, 2015 7:46 pm

Do it the other way round.

Open the tap then no fuel should flow.
Leave it open and apply suction....fuel should then flow.
Remove suction ...fuel flow stops.

It easier that way unless one is octopus related.

NC30 wont start??

NC30 wont start??

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