NC30 running on 3.

arsey30 · Post by **arsey30** » Sun Mar 30, 2014 5:18 pm

Most likely only 1 float valve will be leaking, did number 3 have the fuel in the cylinder.
Would account for smoking, [unburnt fuel] and flooding will kill the engine at low revs, but will cut in at higher revs when the throttle is well open.
Make sure fuel is not running through the vacuum hose past a split diaphragm, it would bypass the float valve and go straight into the head.

mitchyboy01 · Post by **mitchyboy01** » Sun Mar 30, 2014 6:30 pm

arsey30 wrote:Most likely only 1 float valve will be leaking, did number 3 have the fuel in the cylinder.
Would account for smoking, [unburnt fuel] and flooding will kill the engine at low revs, but will cut in at higher revs when the throttle is well open.
Make sure fuel is not running through the vacuum hose past a split diaphragm, it would bypass the float valve and go straight into the head.

Took plug from 3 and it still wouldnt turn. Took plug from 1 and it turned. Went out with the missus following in my Volvo. She said there was no smoke at all today even when thrashing. Bike pulls really well although above a ton (private road) my Volvo leaves it for dead. Forgot how quick my car was lol.

Will order a new fuel tap. Can I just get a repair kit? How can I test the float valves?

Got my knee down for first time 2 years. Felt good!! I love the bike. It feels very stable, fantastic handling, great brakes.

arsey30 · Post by **arsey30** » Sun Mar 30, 2014 7:45 pm

Depends whats leaking.
If it leaks with petrol tap on, then diaphragm/shut off valve suspect, but leaking with tap off suggests the O ring arrangement, but tap not designed to come apart from that side, and dont think O rings available.
Rick O is the best one to ask for parts.

The float valves can be tested by sitting the carbs in a tray on the bench, fed from a dummy or bikes tank, leave for a day or 2 and check overflow pipes.

It is possible to hold the float lightly closed by hand and blow in the fuel pipe or feed fuel into the carbs via a tank.
Trouble is, with 4 floats, 2 pairs of hands required to hold 4 floats closed then release each float in turn.

Post by **Morespeedvicar** » Mon Mar 31, 2014 1:37 am

It does surprise me that nobody's suggested that number 3 carb maybe full a fox piss......................................................................................................................................................................................................

Not meant at mitchyboy just a long standing joke..........on here.....................

arsey30 · Post by **arsey30** » Mon Mar 31, 2014 8:22 am

Mice nesting in air box have corroded RC45 injectors and heads before now, mouse piss is corrosive.

mitchyboy01 · Post by **mitchyboy01** » Tue Apr 01, 2014 1:11 am

I heard they run better on mouse piss.

mitchyboy01 · Post by **mitchyboy01** » Wed Apr 02, 2014 5:03 pm

I have ordered a fuel tap rebuild kit so can hopefully sort it so it's not still on when switched to off. The diaphragms and spring all look in OK condition though. Does the NRP diaphragm kit come with the O-ring to seal to the tank? I found quite a mess on removal. Looks like the o-ring fitted was too big and on tightening the previous owner has warped the mounting (see pic). Where can I get the correct o-ring from?

See where it's warped at the top! FFS.

O-ring

More bodginess!

Does anyone know the o-ring size and where I can get one without ordering online? Thanks.

Hopefully with the correct o-ring and some swearing I can get it to seal up but the jury is still out on this one.

mitchyboy01 · Post by **mitchyboy01** » Wed Apr 02, 2014 5:17 pm

This is going on ebay. Is this the same as mine as it's very hard to see?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... ink:top:en

Cheers.

Post by **Cammo** » Wed Apr 02, 2014 11:31 pm

I got the correct o-ring through the local Honda shop. Critical that it's fuel resistant material, most rubber is not.

egonski · Post by **egonski** » Fri Apr 04, 2014 4:57 pm

Mitch
The fuel filter has been dissolved by the ethanol in our clean fuel!. I had this exact same problem with my RS250. I put the filters in as I was fed up of cleaning the carbs!. They worked fine for a while and then began to break down and eventually block completely. It took ages to solve as we hadn't given that a thought as they were all recently new and only spotted it by chance. The bloody fuel reacts with the plastic hence yours was bent and probably partially blocked, this probably didn't help but I don't think it would cause only one cylinder to die as it feeds all four carbs. I have tried to source metal filters, but despite suppliers knowing this happens, they don't seem to want to help solve the problem by importing metal sets. I still use plastic ones, I think it is good practice to really ensure the fuel is uncontaminated, easier to replace than strip the carbs!!, but I change them frequently and try to run the carbs dry before I leave the bike standing. They only cost a quid each. Up to you of course, but to put your mind at rest it probably wasn't the filter.
Is your track day at Lyden by any chance?, done a few there and it is great for smaller bikes as there as it is a twisty track, my 250 usually eats the bigger bikes and 400s usually do very well, very satisfying!!. Ian

NC30 running on 3.

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Re: NC30 running on 3.