so i have been surfing the local ads for about 7-8 months looking for that right deal. you know the one. that diamond in the rough that only costs a song to get. (note that i wrote "to get").

my buddy had been harassing me about getting one. i've been itching to ride again.

while looking, i've noticed that there just does not seem to be that many 80's bikes for sale, and those that are for sale and run, sell for a decent amount, while those that don't run, are listed for o.k. prices, and may need this that or the other to run, sell like there is no tomorrow.

so what is the story behind the apparent demand?

either way, i found me a deal about a month ago and am very pleased with how it's coming and the progress i have made. what i picked up for the total cost of about 350 bucks is a 1985 honda magna vf700c with 14k miles.

issues when purchased / current status:

1. no spark to the front cylinders - fixed, problem was cold solder joints on the circuit board for the spark control unit.
2. all 4 carbs needed serious cleaning - cleaned, gaskets replaced, and bench synched.
3. rusted tank - currently treating the tank and results so far are very promising.
4. electrical issues with the running lights - kinks worked out and am updating from bulbs to l.e.d.'s

interestingly enough, i am an electronics tech, but have enough mechanical skills that i can work on cars. never thought i have this bike idling in a matter of two weeks of getting it while knowing that the bike had not run since late '08.

anyways...there's my story......

Better check the cams.... they had a problem with wearing the lobes out, due to improper adjustment technique. Most people use one feeler guage and check one valve at a time. These use a forked follower and you need 2 feelers and check/adjust each pair together.
One feeler will cant the follower and skew the measurement....

As you may have researched by now,the first generation of Honda V4's suffered from top end oiling problems.With relatively low mileage and not much cash into it,you may or may not want to spend the ~$300 on the Dale Walker kit to help with that.I've never had a Magna but did own a couple Interceptors.

  I reckon the cost of 80's bikes is coming down to what most things do:supply and demand. There aren't nearly as many around these days but also,some of them are old enough to start becoming somewhat retro cool.Hell,I wish I could find a very clean VF500F and 600 Hurricane for Sunday morning rides but they're just not out there,sadly.Add in the fact that nobody is buying new right now and many people looking for cheaper,more fuel efficient form of transport as well as plenty of people wanting a late winter project to ride this summer and I guess it could all add up to more demand for such things.


What tank cleaning method are you using? I'm a big fan of using the electrode method and sealing with POR-15's  sealer,I've found it to be leaps and bounds better than the old Kreem standby.

in regards to the cams, i have not looked at those yet, but will be. in addition to the bike, i also got an 84 sabre rolling frame with a "bad ingine". no idea what the deal with it is, but it came as a parts bike, what's left of it. i did pull the covers off that engine and the cams are freaking immaculate and heads super clean. i going to take a guess that the cams in the magna are in good shape, but when the time comes, i will be checking those clearances out.

in regards to the top end oil issue, i've been debating whether to do something about it because based on what i have found, if i let the engine get hot before i actually ride it and don't run red line the engine and float the valves, i should be o.k.

i have also read that the oil mod drops bottom end pressure, essentially robbing peter to pay paul and possibly blowing the crank, but i am not sure. i have seen the mod kits on ebay, and from what i see, simply getting an oil cooler adapter and some hydraulic hose, running the hose from the adapter to the tranny oil line will accomplish the same thing. as i wrote, i am considering it and am researching options on this mod.

i had an 86 vfr750 back in '96. i paid 8 bills then for it. had 65k on it and was beat to shit but ran like a rabid horse. sold it about 8 months later for what i paid and still regret selling it. last year i spotted an '86 on local cl for a grand in good shape. still kicking myself for passing on that one.

at this exact moment, the tank is sitting in the middle of the garage floor filled with white vinegar. i will be flipping it in a couple hours and letting it sit till tomorrow afternoon. then i will be draining the majority out and dumping in the 2500 bb's to bang out some more surface rust. unfortunately, no one locally sells por-15, (even a couple of hot rod resto shops.....), so i have the kreem kit. i've heard a lot of people talk bad about the kreem, even the shop i got it from, BUT, they did tell me that if you follow the instructions, TO THE LETTER, it will do the job. so, since i have time and am in no rush to get this tank done, we'll  see how it works. i do have a couple leads on a new nos tanks anyway.

thanks for the responses so far!

update:

so the vinegar that has been sitting in the tank so far has done a pretty good job. in the morning, i will dump most of the vinegar out and pour in some bb's to see if i can knock some more crap loose.

after this, i will do the electrolysis on it.

Hello, I just read your post and I would like to recommend something if you have a chance to try it...
  I purchased an '85 Kawasaki  zl 900 eliminator a few years back, and it had pretty severe rust in the tank, I did some checking around, and found this stuff called Evap-o-rust. I purchases a  gallon at autozone, and read the directions, but it didn't say anything about the tank situation. I called the company, and the lady on the other end swore that the stuff was like magic on gas tanks, and there was no need to coat the tank afterwards, so I tried it and it worked pretty well, no rust after 4 years.
just my humble opinion...lol  
i think it cost like 18 dollars for a gallon, and it works on guns.....just don't use it on cold blue....hehehe   slips away like a fart in the wind.
good luck with the bike, and keep it between the ditches

I am still amazed of the amount of confusion that circulates concerning the cam's on 82-83 model VF's.



There are two root causes of premature camshaft wear on these engines:


#1  The first two year models used camshafts that were solid. The lobes and rocker arms experienced wear due to lack of direct lubrication of these two parts. The amount of 'splash' from the journals was simply not enough to provide ample lubrication. The cams listed in the service bulletin , as well as later production engines are hollow. They can be identified by the oil discharge hole in the base circle of the lobe, and a 'cup plug' on one end of the camshaft.  This allows pressurised oil from the cylinder head journals to flow into the center of the camshafts, and to spray oil directly on the rocker arm pad and lubricate the cam lobes.



#2   The "oil control bolt" p/n 90045 MB2 000 is the part that allows oil from the pump through the external oil pipe's to reach the camshafts. The sizes of the orifice was changed to allow more volume of oil to reach the critical parts in the head, without causing enough pressure drop to cause problems elsewhere in the engine. If you have a 1984 or earlier model, you NEED this part to prevent a future top end failure.



The after market oiling kits were designed for racing use to send a large volume of oil to the top end when the engine is being run at high RPM for extended periods of time. However, they are useless if the new style hollow cams are not used. Not to mention the pressure drop at the main and rod's plain bearings!



The other normal (?) problem is cam chain tensioner noise, that many mistake for a cam/rocker issue. If you hear excessive noise from the top end, try this: Start the engine in neutral and rev to approx. 3000rpm and let off the throttle. If the noise increases when the throttle is closed, the tensioner lock plate/rod is worn and not holding enough pressure on the chains to keep from rattling.



So, make sure the camshaft's are new style, get the correct oil control bolt, and you should have a perfectly good VF!

A lot of used 80's vintage MCs were shipped to and sold in european markets. I worked at a dealer here in CO that sent 2 or 3 containers a year over. The bikes were trade-ins that were not moving off the used bike line.



Phosphoric Acid is what you use to clean and etch gas tanks. Neutralize and clean with Methyl Ethyl Ketone MEK.



Really rusty tanks can be sandblasted by pouring 2 cups of sharp sand into the tank. Use a long tubed blowgun to blow the sand around in the tank. Move the tank around to all positions even above your head. Blow all the sand out and then do the chemical treatment above.



3M used to make some tank sealer that was better than the white kreem sealer you buy at the MC shop. I have used the white sealer with success. It does not hold up to some fuel additives or cleaners. You might ask at a radiator shop what they use to seal gas tanks.



I ride a Suzuki GT750 74 vintage dinosaur.

Most radiator shops will boil a tank and seal it relatively inexpensive.  I did a few about two years ago.  Just make sure that whatever sealant you use is compatible with the alcohol and mtbe blends they are using in the fuel.

yeah, i have been reading about many people applying this "oil mod" to their bikes regardless of year, but have yet to read where 85-86 models had issues with premature lobe wear.

i found an article written by a fellow that ran honda v4's through factory tests where they literally beat the hell out of them and never found lobe wear to be an issue as long as the motor was allowed to warm up to "hot" before actually riding the bikes.

i also just got off the phone with a fellow that stated he sold quite a number of the 85-86's to a dealer in denmark back in the 90's and he told me that the 85-86 magnas never had an issue.

so, i'm not worried about the premature lobe wear at the moment.

update on the tank.

flipped the tank over last night and drained it this afternoon about noon. believe it or not, the tank is about 95% rust free with what being left is very small pits with rust still in them. i will be setting this tank up for the electrolysis treatment to see if that takes care of the final bits. i have also decided that as soon as i have that done, i will be filling it with gas and go from there. the tank wasn't lined from the factory, so why should it be any different now as long as i have it cleaned out well enough, although, i will be running an additional filter to be on the safe side.

on a side note, i have worked a deal with a fellow that has a new in box from factory tank and will have that within the next two weeks.

here you go:

Right on. Now cut the frame down, rewire it for simple gauges and a kill switch, mount a solo seat and new license plate/tail light and your done. Haha I have pics of my new (2nd) bike if you want to see what I'm talking about. Purchased as is it's 2k, currently paying it off paycheck to paycheck as I got raped by the IRS. It's a 84 Honda VT500C, 34k and very clean. Even before the bobber conversion, whoever had it before took real good care of it.

Jason

Older bikes are in demand because

Cheaper to insure, less complicated, cheaper to buy, cheaper to repair, less intimidating...For a person who likes bikes but isn't hard core or wants the latest tech, they are the ho ticket.

making decent progress this bike.

i have that 84 sabre rolling frame that i could play with.

you can get the POR-15 on ebay for a decent price.  fortunately I found a place locally for me where I can get it and not have to pay the shipping :)

Sorry for the hijack...  I picked up a 72 Honda CB450 twin cam not too long ago.  I've already rebuilt the carbs and took care of a few other things.  The main problem is the tank.  The previous owner let gas sit in it for 10, yes 10, years.  It didn't rust through, and I was able to clear to balancing tubes in the rear.  I just need some good recommendations on getting the rust out.  I was going to use the Kreem kit, but it's a PIA to get everything coated well enough.  I didn't know POR15 made something for gas tanks.
Anyone have some ideas for me?

got to tell you, there are quite a few sites about electrolysis and the like.

what i started with on my tank is dropping about 2400, (that was the quantity in the container), of daisy stell bb's into the tank and shaking it. i then washed it out with water and simple green. i did this several times.

this worked, but not that well as i did not repeat it more than three times.

i then filled the tank with white vinegar and let it sit for 24 hours. this ate a lot of what was left. it cleaned out very well.

unfortunately, there is really no way that you can completely fill a tank to the rim, so you have to rotate the tank, which i did. problem is with the "flash rust" that appears when the clean metal is drying.

i then tried the electrolysis and believe me, it works. i only let it sit for about 6 hours and then cleaned again.

the problem is, one you get rust in a tank, it is very difficult to fight it back if you don't line it.

i did buy the kreem kit, but i found a new old stock tank for a great price that i will be getting, so no use in lining the current tank. the other issue with kreem and even por15 is that you have to follow the instructions to the "t". if you don't, you will later have problems even more difficult to deal with.

now, while i am awaiting that tank to show up, i am using the old tank. i am using a new filter and have filled it up.

personally, if you can get that tank rust out of there, and then dry it out fast enough, you should be good to go if you get it back on the bike and filled with gas immediately. the gas will then provide some coating to now protect the once bare metal.

i also know that you can take your tank to a radiator shop and have it hot tanked, but i believe that strips paint and everything, but have no experience with this, so i am not sure this is the best route either.

hope this helps.

What I've done in the past is hot soapy water and a hand full of marbles.  Just keep those marbles rolling around in there for a while and it will knock most of that crap out.

I've used the Kreem kit and had good results, but I've talked to many wrenches that had a nightmare with it.  If it doesn't coat 100% you will get fuel between it and the metal then it starts to peel blocking the petcock and then you really have a problem on your hands.  

I'll upload some tomorrow. Heading out for the night though

Jason