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Discussion Starter #1
I know, I know, why didn't I do it before I started riding it?

Well the bike comes from a known source. I know both of it's last two owners, I know it to run fine and be viable as is. Basically it needed a tire, a battery and licensed to run. It still needs a back tire, the rubber is fine but nearly bald, but money is always the thing. So I just got the money, she's getting stuff done today (or tomorrow, depending a bit on weather), save for the back tire.

A few things to ask though. I remember the last time I owned a Nighthawk 450 the engine, even with everything adjusted correctly was still fairly clattery at idle. Same was actually true of my 700S as well. As soon as the revs pick up even a little the noice lessens, but they just aren't super quiet at the best of times IIRC? I remember the guy at the honda shop saying, that at idle all Hondas of that era make some level of cam chain noise, as long as it's not loud or obnoxious it's fine.

Now IDK about the strength of my cam chain tensioner spring, I'm thinking of giving it a little prod with a scredriver while I'm in there doing valves. Of course I don't wanna overtighten, so does anyone have any hints on this?

Also, will I need bent feeler guages for the valves?

Thanks ;)
 

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Discussion Starter #2
Oh yeah I also gotta make a home made manometer. I think my carbs are close, it seems to run good and idles nicely at less than 1000rpm which tells me it's ballpark, but being a perfectionist, it's time to get creative with clear tubing zipties a board and tranny fluid.
 

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I'm not the best person for noises :eek::lol::lol::lol::lol: but I'm learning to hear again. The tensioning of the cam chain should be done at idle hot. IF the tensioner is stuck, happens sometimes, of the spring is weak, rarely, then using a screwdriver to gently push the tensioner is OK. I'd advise against doing it as a normal function since it will be way to easy to over tension and cause wear. Yes, there'll be some cam chain whirring at idle, shouldn't be a rattle.
While you're adjusting things do the balance chain.
Normal feeler gauges fit just fine w/o bending.
The idle speed for this engine is 1200 +/-100 rpm and yes the tach is inaccurate. Mixtures can only be set at the recommended idle speed.
 

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If it sounds like and old Singer sewing machine clattering away then everything is fine. No clatter, too tight. Overly loud and clunky, too loose.

You will know if the cam chain is too loose. You'll be able to hear it clanking on overrun.

+1 for everything LDR said.
 

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Discussion Starter #5
Yeah what I'm hearing is a light "tic tic" nt a clack clack, so I'm not overly worried. I did do a running caqm chain adjustment and oddly with the locknut loose the noise clears up a little, but as soon as you lock ot back down goes to about same as before. I'm really pretty certain most of it is just normal though. Bike only has like 20K on the odometer.
 

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Discussion Starter #6
I'm not the best person for noises :eek::lol::lol::lol::lol: but I'm learning to hear again. The tensioning of the cam chain should be done at idle hot. IF the tensioner is stuck, happens sometimes, of the spring is weak, rarely, then using a screwdriver to gently push the tensioner is OK. I'd advise against doing it as a normal function since it will be way to easy to over tension and cause wear. Yes, there'll be some cam chain whirring at idle, shouldn't be a rattle.
While you're adjusting things do the balance chain.
Normal feeler gauges fit just fine w/o bending.
The idle speed for this engine is 1200 +/-100 rpm and yes the tach is inaccurate. Mixtures can only be set at the recommended idle speed.
One thing I learned about that balance chain, if you use a socket, tape it to the extention cuz it's easy to lose and then you are stuck removing the clutch cover.
 

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First time I adjusted the balance chain I wasn't thinking and was using a cheap 1/2 to 1/4 adapter between my ratchet and socket. Snapped it clean off in two. I had to very carefully fish it out with a magnet. :-?
 

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Discussion Starter #8
Well I didn't get it done yesterday, rained all day but sun is out today, so time to get on it soon.
 

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Discussion Starter #9
Well I'll be damned, she is prolly the quietest Honda I've ever owned now.

I didn't use a screwdriver on the cam tensioner, I figured light finger pressure would be less likely to be too tight and it seems to have been just the thing.

It's still got that tic tic sewing machine sound, but so quiet!
 

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Discussion Starter #10
I don't even think there's significant leak on the gaskets (which I did not replace becauase the local Honda shop is no more). Certainly does take a light touch on the cover bolts, mine are original too!
 

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Yep, snapped one of those cover bolts once.

Sounds like she's in good nick, got pics?
 

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Discussion Starter #13
Crazy as it is, the oiginal mufflers are still functional, not rotted out. BIG difference between Honda exhaust quality between the 70s and 80s. My Nighthawk 700S had original exhaust too, not at all rusted out.
 

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Very clean bike. I see you have the coveted crash bar. Nice!
 

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Discussion Starter #15
I've actually always wanted to own one of each Nighthawk bike. The 650 has always been my most coveted one, but I talked to a guy the other day swears the 550 was the best model.
 

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you are both wrong. The best Nighthawk is the CB700S
 

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Discussion Starter #17
you are both wrong. The best Nighthawk is the CB700S
IDK I think that's arguable. I'm a former 700S owner (2nd gen) and I was not a huge fan of the 16" front wheel. It's great on the highway but not near as friendly out in the country. I think a 550 or 650 would be nice, maybe a 1st gen 750. My 450 is the simplest little around town Nighthawk that's still big enough for occasional highway trips. I think all the NIghthawk line has a lot to be said for it. Save for maybe the 1st year Nighthawk 650, which was essentiially just a CB650 with Nighthawk logos on it. Not a bad bike, but not a Nighthawk reallly, not in comparison with the others. For that matter the 250 and 450 aren't anything new or special either. The 550, 650, 700 and 750s all had those hydrolic lifters and chain driven alternators for thinner profiles, and with all but the later 750s being shaft driven, all are the logical progression of the CB line. Personally I think they're all great bikes. I never owned a Nighthawk 650 but I did own a 1980 CB650, and it wasn't a bad bike. I've yet to own a 550, 650 or 750 and want to own them all maybe someday.
 

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What do you mean 2nd gen? I thought the 700s was a 2 or 3 year only bike. I've never ridden a 700 with the 16" wheel but I have a 16 out front on my 450SC (entire front end from aVF500F) and I find that it is a bit more nimble out in the twisties. The thinking in the 80's was that the 16" wheel has a lesser mass therefore reducing inertial and gyroscopic forces allowing it to change direction more quickly. Clearly they were wrong though because I don't see 16" wheels around.
 

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Discussion Starter #19 (Edited)
What do you mean 2nd gen? I thought the 700s was a 2 or 3 year only bike. I've never ridden a 700 with the 16" wheel but I have a 16 out front on my 450SC (entire front end from aVF500F) and I find that it is a bit more nimble out in the twisties. The thinking in the 80's was that the 16" wheel has a lesser mass therefore reducing inertial and gyroscopic forces allowing it to change direction more quickly. Clearly they were wrong though because I don't see 16" wheels around.
I was wrong, I thought the early ones had a bigger front, they didn't. I guess what I meant was pre and post tariff. All the early 700s and 750s before them had 16/16 rear and front. It just gave it slightly odd handling I never did care fore on ****ty back roads. All other Nighthawks feature 16" rears and at least 18" fronts I believe.
 
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