New Guy from uk.

[smiley]

honda night hawk.jpg (14.68 KiB) Viewed 10924 times

Hi all, Im in Cambridge in the Uk.
I have just acquired a 1982 Honda Nighthawk 650, this is originally from America and was bought over by the usa forces at somepoint. it is registered in the uk in 1987.
I took this on as a project
so far problems I have had are:
no keys, leaking fuel tank, and the main one which is cannot get the bike started.
Handle bars were on the wrong way round as well!
New battery, dismantled the ignition barrel so I can turn it on,Changed the plugs, had the carbs soaked in a sonic bath to clean them through. checked the valve heights and also the valve timing. we have a spark and fuel is getting through to the plugs but still no firing. Very occasionally it will produce a backfire, but will mostly just keep turning over. The carbs are sucking well. any ideas or pointers would be great. I will try and upload some pics but its not very exciting to look at. The best parts are the powder coated wheels!!!!!

[cb650]

Did you remove the idlejets? They should be removable in the 82. Does it still have the pos automatic fuel petcock?
The bars are unique to that model and a handfull of others.
In UK they are called a Luxury Custom for some reason.

[Folsoml]

Welcome here!

Check to make sure your spark plug wires are going to the correct plugs. Coil #1 (left) wires should be going to plugs 1 and 4. Coil #2 goes to 2 and 3. How is your compression?

[Volker_P]

Welcome here!

The SC probably is a very unique bike in the UK, similarly like the earlier CB650 models, see viewtopic.php?f=2&t=8085

As written, check plug cable positions first!

[smiley]

Hi guys, not been out to the garage much as back to work and its dark and rainey here in England, but did check the coil cables and they are in the right position, maybe I'll get to have a play on sunday

[Volker_P]

Basically one can generate a similar effect by reassembling the advancer the wrong way.
For the details please refer to:
viewtopic.php?f=2&t=6933&p=47196#p47196

[Folsoml]

I had this exact effect with my latest project--a 1980 CB750C--and the previous owner had the plugs going TO the coils reversed. Check that also.

[smiley]

Hi guys so after 2 days going over this bike, still no start
I have done what has been suggested and even gone over the electrical connectors
I have found a crack on the intake manifold on cylinder 4 but would of thought It would have started on 3 cylinders?
Anyway I'm a beaten man and have decided to put it up on ebay as I just don't have the time or cash to get it running. thanks for all your help!

[Volker_P]

No need to give up that early.
But right, basically you will need some time for a bike of that age to keep it running.

[MEHall]

Volker_P is right, dont give up so soon. It took me a half biking season here in Sweden before my electrical problem showed up to be a broken harness!

[smiley]

Ok, so after some time away from the bike I have decided to carry on with the bike, I got myself a compression kit.
cylinder1 was 115 psi, 2 110psi, 3 60psi, 4 80psi
I popped some oil down the plug holes and the pressure improved.
cylinder 1 went up to 140psi, 2 115 psi 3 130psi 4 135 psi

so am I correct in thinking that the rings need replacing?

[Volker_P]

Probably yes, but it depends also on how long this bike was not running. Possibly the rings are just stuck a bit and get free again after some time of running.
It should run like that somehow anyway.

[jcasey007]

also from the UK here

the starting procedure (outlined on this site) worked for me, basically

open the throttle full 5 times, pull the choke and hit the starter button.

mine would only start this way

[smiley]

Hi Guys, just an update.
Managed to get the bike started and running. the wires to the coils were wrong. It now has a massive oil leak. I don't think its the head gasket and believe its the rubber coins. I was going to take the head off but have discovered the previous owner has rounded off 3 head bolts and there was actually one missing as he had also stripped the threads. any one got any ideas how to remove them. thanks

[cb650]

Try a set of 6 point. Might try a standard set to and drive something smaller on. A few good hammer blows driving something on will help break them free also. Be sure all the crap is cleaned from the whole length of the bolt. It gets packed in like cement.