Topic: 83 Nighthawk 550 question

[Laminar]

so there is no tuning of the jets? just take em out, clean them,  and put them back in?

That's probably why no tutorials have mentioned it.

Correct. They get screwed in fully. Carbs on the SOHCs have adjustable metal floats and a screw on each carb to adjust idle mixture, but the Nighthawk has plastic non-adjustable floats and no idle screws.

One thing you will want to do is at least a bench sync of the carbs. You want to make sure that when you open the throttle, all four throttle plates are opening up the same amount. If one opens more than the others, that cylinder will be doing an unequal amount of work and the bike won't run right.

What I do is take two 1/8" drill bits. I open the throttle and place the non-drill end of the bit into one carb (#2 is a good choice) so that when the throttle plates close, the carb's throttle plate closes on the drill bit and it holds the plates a little bit open. Then I go through and try and slide the non-drill end of the other drill bit under the other three throttle plates. If it slides in too easily, I close that throttle plate a little bit by adjusting the linkage between the throttle plates. If there's a lot of resistance or it doesn't slide it at all, I open that plate a little bit. Keep in mind that if you use #2 as the standard, adjusting #3 affects #4, so do #3 before #4. It only takes a few minutes, it's as easy as turning a screw, and the results are great.

[bull city]

hey Laminar, can you help me on this?

Got the new bike and I am going through to get everything functioning.

The brakes were locked, I took them off, pressed the piston back in, flushed with new fluid and they seem to be doing well. I plan on rebuilding them as soon as I get everything functioning. No point in spending money on something before assessing the whole bike.

The clutch: the master cylinder was pretty much dry. The clutch would not engage and there was no resistance on the lever. So I flushed the system with new brake fluid. The bleed hose was coming out clear and I was getting a lot pushed out with every squeeze. But- I never got any resistance on the lever, the clutch would still not engage. What should I look for next?

I haven't started the bike yet and no battery is hooked up at the moment.


Thanks-

[bull city]

wait.. since this is a wet clutch and I need engine oil for it to work, should I run the engine a bit to see if that solves the prob? I'll try that.

[Laminar]

You should get resistance at the lever without running the engine. As far as I know, the fact that it's a wet clutch doesn't affect its engagement or disengagement.

What method are you using to bleed?

When I flushed my clutch fluid, I grabbed a brake bleeder kit (basically a little jar with a tube going into the bottom of it) at an auto parts store. I put a little fluid in the jar so that the tube was immersed. I then filled up the clutch line by putting a funnel over the banjo fitting and pouring fluid in there.

To bleed, I'd pump the clutch lever a few times, hold the lever in, then open and close the bleeder screw. I heard that you don't want to pull the clutch lever all the way to the handle, but leave a 1/2" gap. I'm not sure if that's important or not, but it's what I heard. I made sure that there was lots of fluid in the reservoir and bled it a lot - pump several times, hold the lever in, open and close bleeder screw.

It should eventually build up pressure. It was a pain when I did it, hopefully it works for you.

[ColinMc]

Is the clutch slave OK? I'd check the seals on that...

Wait...the clutch won't engage? As in when you put it in gear you can still roll it no matter what? Since you have to change the oil anyways, i'd pop the clutch cover off and have a look-see in there. Usually by default if there is a problem with the clutch it stays stuck so the clutch is constantly engaged.

[bull city]

I think I had it backwards. I can put the bike in neutral and it rolls, put it in gear and it doesn't. I just cant have it in gear, pull in the clutch and have it roll in gear. is that engaged or disengaged? i figured the pulling of the lever would  "engage" it, but maybe it's counter-intuitive?

Someone on another board said to pull off the slave and put a clamp on it to keep the piston from moving. Not clamp it tight, just keep it from moving.You can evidently bleed it much faster that way. The idea is that brakes have the disc to stop the piston which makes it much easier to bleed brakes.

sorry for my noob questions and thanks for the help.