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A few months back I was gifted a couple of late 80's Yamaha sports bikes. These models encompass a lot of design changes that would be adapted by the industry as a whole for sports bikes.


One was deemed a "runner" and was was a parts bike (bent subframe from a crash and rusty valves from being stored with no airbox.) As you can see it needed A LOT of work,








Here it is today, not much to look at still, but man is it fun to ride. Comfortable too for my 6' body.




Rebuilt brakes (all three) with new pads and stainless lines

New battery

Cleaned the tank (vinegar + rocks)

New fork seals

New float jets and bowl gaskets

New o-ring chain

New plugs

New throttle cable

New petcock


Took some figuring to get it to run. The electrical system looked like it had spent a few months at the bottom of a lake so I replaced it with the one from the parts bike which was pristine (given the year.) Got another set of clusters off of feebay. The stock brake setup sucks serious mule so I got a set of 4 pot Sumi's off the bay and I'll make adapters for the calipers. I got the rotors too (all for $30!) but it doesn't look like there is enough clearance between the fork tubes for an adapter. I might pickup an FZR front wheel (where the brakes come from) or look into replacing the entire front end.


I'm still trying to decide what to do about paint. None of the body work (what little I have) is in any kind of shape so I'll probably just complete the rattle can treatment and leave it alone. It won't ever be a show bike unless I can find a set of fairings for it and even then I probably won't put the effort into it. I don't really feel any attachment to sports bikes so I don't think I'd have the motivation to go full out on it. I really just want something to ride around as I've been away from bikes for too long as it is. Some pics of the stand I made to enable me to change the chain,







After I've driven it awhile I'll probably sell it and this other bike to buy something newer like a VFR or maybe a KLR650,




This is an '81 Honda 650 Nighthawk that I was also gifted. The PO (a friend of a friend of a friend) said it wouldn't ever run right unless he had the choke on halfway and sometimes not even then. He was fed up and going to haul it off to the scrape yard. They said they would only give him 30 bucks for it so he called me and said if I came and got it I could have it. I was at his door 20 minutes later.


Got it home and discovered within 10 minutes that the band-clamps around the intake boots were all stretched past the point of being able to tighten down. I threw on some spares from the 700 and it fired up and purred like a kitten choke off and all. Took it up through the gears and it runs great.


Still to do,


700 - synch carbs, new tires, ride like hell.

650 - synch carbs, clean tank (pretty rusty), clean carbs, tension or perhaps replace the chain, ride like hell.


Not my bag and I'd have sold it already, but the wife has been wanting to learn to ride and she likes these older cruiser style bikes. If she takes to it then she keeps it. But if her interests wains which it's almost certainly going to (sorry honey but I know you too well) then it'll get sold to finance something newer.


Anyway, that's where my energy has been going lately.





Edited by lostinthe202

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The 650 looks to be in decent shape for it's age. Isn't that a lot of bike for a new rider though? I don't really know - only what I've been told. Haven't ridden much myself - just some dirt bikes.


I might have to pick your brain - I was gifted an '83 VF500 Magna a couple years ago. It's in my shed and hasn't run for probably 8 or 10 years. I have a bunch of new parts for it and some extra carbs, etc. Just haven't had the time to look at it.



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Yeah, the 650 is in great shape for it's age. The chrome has been really well maintained, best of any bike this vintage that I've owned. The exhaust canisters both have cracks at the joint which is a bummer, but it's just cosmetic and not very noticeable so it's not too bad. It's missing on side panel and the seat is not original, in fact I don't think it's for that bike at all since there isn't any way to attach it.


Since the first post I've discovered that the air filter element is missing all together (bad) and that the PO must've been religious about changing the fuel filter and only used the stone kind (good) so the carbs really didn't need a cleaning.


I'm trying to decide if I want to drop the money on a carb synchronizer. I'll be working on more bikes in the future so it would probably be worth the investment, but I'm waffling. I've built manometers before and I'm tempted to just make another, but at some point you just gotta bite the bullet and throw down for the correct tool. If anyone has suggestions I'm all ears.


I'm trying to decide what to do with the NightHawk. I don't like cruisers so I'm thinking of turning it into a cafe bike but there are two major problems. First is that this being a cruiser, it's really low in the middle which is good for a low center of gravity but bad for my long legs and rear-sets. Second is that it's in such good shape that it would be a shame to cafe it and ditch all the good chrome.


Took the 700 for a nice long ride today. Once fully warm, It kept stalling if it had to idle for more then a few seconds, like at a stop light. I really need to synch the carbs too and eliminate them as a culprit. After that I'm going to look for some sort of aftermarket fuel pump as that might be an issue too. Seems to me it was intermittent during the initial troubleshooting phase.




If the airbox is still attached to the carbs, the engine is probably in good shape. Hopefully the carbs and tank were drained, but it's not that big of a deal if not. Full concentrate simple green is a fantastic carb soak solution. Submerge the carbs (only two of them right?) for a few hours and then rinse with water then carb cleaner. It doesn't a great job. Just make sure to remove the diaphragms from the carbs first as you don't want the simple green to degrade the rubber. Same with the floats too.


Pull the plugs and pour a teaspoon or so of MMO in the cylinders and leave overnight. This wont' work as well with a V motor since the cylinders are at an angle, but you could turn it over by hand a few times to spread the oil around before leaving it for the night. Then a bunch of times with the starter the next day to push out excess MMO and reseat the valves. I bet it'll run fine.



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A local dirt bike shop let me borrow their carb sync meter when I set the carbs on my FJ600. Said they weren't licensed to work on street bikes but they had the tool and I could do it myself. Heck, they didn't even charge me to use it lol

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That's cool of them. Seems like I can never endear myself to auto or bike shops that way.


I ordered some vacuum gauges from Mcmaster and some needle valves and various fittings and hoses and I'm making one. I've done the homemade one from canning jars that is described in older Clymer manuals. It actually works pretty well especially if you use a light weight oil like 10 weight instead of water to cut down on oscillations in the readings. but it's not very convenient to store so I figured to make something more shop friendly.



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