1982 Nighthawk Issue

[5.4L to Freedom]

Hey guys, its been a while since on the forum... I sold my CB and got a Harley (please don't banish me)

However a girl I know has a nighthawk and because I spent so much intimate time with my old CB I just work on hers all the time now, and this bike finally stumped me.

So any ideas what would cause the following:

Has symptoms of sucking the carb bowls dry, however auto shutoff has been bypassed and I know the tank filter and fuel tank are clean. I doubt there is a clogged jet because the oddest part about this is this bike starts up fine without the choke on. My old CB had a hard tiem starting even with the choke on... I've never heard of a CB starting in 50 degree weather without choke.

The choke thing indicates a sticky choke or a super rich condition. However unless you nurse the bike... it dies out. Sometimes even when you nurse it it dies out.

I'm going to throw fuel stabilizer in there to test for water in the fuel, and ride with the gas cap open (check for clogged vent), however is anyone aware of any other issues such as charging system or anything that can present themselves like this? All help is appreciateed we are supposed to leave on a 200 mile road trip this evening, and right now i'm not comfortable with throwing stabilizer in and just going hoping for the best.

[Volker_P]

Welcome back.
Good to know you are all right.

However a girl I know has a nighthawk and because I spent so much intimate time with my old CB I just work on hers all the time now...

Of course everyone here appreciates your purely nostalgic reasons to work on this bike.

Has symptoms of sucking the carb bowls dry, ...

This would mean it sputters and gets alive again at least for a short while when pulling the choke. That's what it does? Would be a bit strange together with "starts always without choke".
Did you already check for a clogged air filter? Try a short turn around the block without it to see whether it is a mixture problem.

[5.4L to Freedom]

Well believe it or not, I solved this one and man am I a dummy! Turns out the new fuel line I installed got hot and collapsed on its self while the tank was on, and of course once the tank was pulled off the line popped back into shape so I had no idea that was actually occuring.

Ironically once I solved that issue on the test ride I discovered weak top end engine power which led me to find out some interesting stuff!

The bike has 27500 miles on it, and is ridden quite regularly. Shockingly it has about 5 years on its current airfilter and plugs. Tonite I'm going to start tuning it up... its way over due for a carb sync and I need to dig up the sync tool. I just find it amazing the amount of miles on it and lack of maintenance how awesome of a bike this is!

Now having another road bike to compare it to, you 650 guys have no idea how refined those bikes truly are! After riding the Harley then hopping on 650 I was in shock. It felt like I was riding a hair dryer lol. Next to no vibration, smooth clutch, easy shifter, quiet, and a good ride. My only beef was the bike felt like it didn't have any balls. I was riding it like I stole it, and kept saying 'dam it where's the balls' and was incredibly disappointed... soon to find out I was going 90 mph in about the time it takes my Harley to get out of first gear. So it felt like there was no balls, but man, these 650's are decieving!

[Volker_P]

Good to hear you found that tricky fuel line issue.
Funny that you describe a CB650 as a real step forward. Compared to a Harley it might be because that's almost 1970's against WW2 state of the art. Never try an actual bike!
One reason to keep my CB is that even with that old fashioned chassis you still go easily beyond speed limits and stuff. With an actual bike, maybe even with a fairing, you will loose your driving license long before you get the idea of a feeling that you really move forward.