Hey everyone

Had my NC30 race bike sitting for 2 years without starting and have issues since. Just wanting to get it running smooth again before selling it, but it has been proven a headache as of late. Cleaned the carbs as they were gunked up from old fuel (cleaned one at a time as not to mix up the parts) and then replaced seals while I was at it. Pulled the spark plugs out and gave them a clean due to some carbon build up, sparks were not sparking well until after I cleaned them, so all good now. Bought a new battery as the last one was dead.

Now the bike starts with choke and idles without it, but the exhaust note doesn't sound right. Went about and touched each exhaust to find that only 2 of the 4 exhaust pipes were hot. Sitting on the bike, Rear right pipe was hot and rear left was cold while the front left was hot and the front right cold. I have cleaned the carbs and cleaned the spark plugs and all plugs showed blue spark. Could there be an issue with compression?

I am also running a HRC carb set up and i turned the mixture screw 2.5 out...I just read it should be 1.5 turns out. Would this cause a lot of issues other than running too rich?

Really want this fixed before I sell it.

Thank you all in advance :)

Cheers
Phong

I had similar issues with a bike that had stood for years and had gunked carbs, you may need to get new pilot jets as they are very narrow and even with cleaning they could still have obstructions that are stopping fuel from flowing freely and causing it not to idle on those 2 cylinders.

Next have a look in the carbs, where the butterfly seats there are 3 very small holes, these can again be blocked and cleaning may not have cleaned them out, get some compressed air on these to ensure they are clean and free of any blocjages. Mine weren't even after cleaning with carb cleaner and a toothbrush, it was only after i had used a compressor on them that it idles on all 4 nicely.

If you increase the revs to pick the carbs up off the pilot circuit do the other 2 cylinders chime in? if so you have a blockage on the pilot circuit somewhere which you can solve by running through the above.

Where is the bike? i have a mate looking for a f400 race bike so may be interested. Could you give me an idea of spec.

Good luck doesnt sound like there is a whole lot a miss with it.

Hello 28hodge

Thank you for your reply and sorry about the late notice! Been busy and forgot about this post.

I will pull the carbs out again and have a look at the butterfly seats you mentioned...I never noticed them so I'll make sure they are clear of obstruction. I have cleaned the pilot jets very thoroughly and didn't stop cleaning until I could see light through the tiny holes. So that should be all good.

I am from Australia and judging from your location, you're a bit far to purchase the bike? Unless your mate is from Australia, then I'm in Northern suburbs of Melbourne.

Thanks again.