NC30 Fuel/Electrical fault?

[thedonsRVF]

Before winter the bike was running fine, no problems at all.

After winter it would only run on 2 cylinders so replaced plugs & fuel, now starts fine on choke, does sound a but lumpy to start with but then settles down when reducing choke & sits on idle.

First time out
Runs fine initially, up through the gears 1-6 without going over 5000 rpm, nice & smooth, as soon as I gave it a good bit of throttle, it took off then started to splutter, down to 3 cylinders & then died & wouldn't start again, even with a push & trying to bump start it wouldn't fire. Thought I may have flooded it trying to start it so had to push it 3km home.

Checked plug leads for cracks & fuel hoses for any kinks but all look fine.

2nd time out
Starts fine & runs well initially, same problem after 10 mins or so of easy riding all around 5/6000 rpm, starts to splutter but thankfully manage to limp home on 2 or 3 cylinders.

Anyone any thoughts? Could it be once it heats up something fails or?

Has the following mods
- Tyga Larger Capacity Carbon Airbox Lid
- Pipercross Dual Density Filter Foam
- K&N Crank Case Breather
- R1 Reg/Rec
- 120 Dynojets/Drilled Slides (2.25mm)/Rick Oliver Needles (rasied)
- Ignitech Programmable CDI (Advanced Standard Map)


Just looking for some help before putting it into an expensive garage.

Thanks in advance.....

[CMSMJ1]

30 or 35?

If it is a 35 and you have 120s in it, then flooding it is the answer

[thedonsRVF]

30, it's in the title :)

Any thoughts? It's Alex's old Lucky Strike

[VFRkieran]

Fuel vacume hose has possibly perished and has gone so soft and rubbery that its just closing up with the extra suction when raising the rev's.

Or your fuel tank breather is blocked causing fuel flow to cut off when it warms up.

Both are easy and cheap to check and replace, if it was me id do those first before going any deeper.

[Cammo]

That's what I'd be checking also.

You can check to see whether the tank breather is blocked by opening the fuel filler cap when you have the running issues - if you can hear air being sucked into the fuel tank when opening then it's likely the breather. Or just remove the breather and see if you can suck air through it.

Does the bike have an aftermarket fuel filler cap? Some I've seen don't allow the tank to breathe properly (the standard filler cap has an air passage). I've had to drill a small hole in a couple of aftermarket caps in the past to eliminate this issue.

[CMSMJ1]

30, it's in the title :)

Any thoughts? It's Alex's old Lucky Strike

LOL - sorry mate

Yeah, as they say - start with simple stuff

[marti]

Sounds like its running rich, dirty air filter??
What colour are the plugs