A VF 500F's tale; ideas on replacing cams?

I have been involved with this forum before. I have an 86 VFR 700 F2. Its a daily driver now, but its not yet up to my expectations. More on that later, I have now switched to my son's 84 VF 500 F. You might remember that I am an advocate of taking the top end down to the point where the heads can be retorqued before going into the tuning of any vehicle. I was going to do show my son how to do this. My son lives apart from me (divorce) and this summer he bought, against my better judgment, an 84 VF 500F, off a small Christian College student on the North of LA, the other side of LA from either of us. It was bad deal from the get go. Last week I got to see the VF on a jack for the first time, partially disassembled, in preparation for a valve adjustment.
I had the experience of taking my 86 VFR 700 cam mechanism apart (gear driven cams) behind me. The VF 500 was, however, a far more complicated procedure then the VFR had been. I did not intend to attempt it except that when I went to do the valve adjustment I was unable to replicate what I had observed on the VFR. To wit, that the cam lobe ends did not seem to automatically point at 11 and 1 o'clock when moving through the successive TDC firing positions in order to check the original valve lash clearances. Cylinders 1 and 3 were just what I expected from the work I had done on the VFR, but cylinders 2 and 4 were way off, especially with respect to the front head's exhaust valve timing. This appeared to be around 30 degrees advanced. The front head intake valves were also off, retarded by 10 degrees. I was flabbergasted.
I had personally twisted my son's arm to get him to do a compression test before he rushed impatiently into purchasing the ’84 VF. The compression had been 160 psi on all cylinders with the motor moderately warmed up. I never rode the bike, not having a helmet at the time. He was, himself, a first time rider/purchaser. He was too intimidated to ride the VF for more than a minute or two before he jumped at it. It ran and that convinced him along with the college boy's assurances about the bike and about the genius of his motorcycle mechanic. Not too far down the Freeway toward home the VF temp guage pegged. I drove 40 minutes west down the Ventura Freeway and found the 86 VFR 700 F2 I am driving today, unridable for $500.
Now, here I was on the hard garage floor of the house my ex had stolen from me, looking up at my son's bike with my hands covered in motor oil. It had appeared to have even and acceptable compression when he purchased it that blistering hot day at the end of June. How was it so that it ran with it's front two cylinders running with their valves seriously out of time? Not only that, he had driven it a couple 100 miles like that. He had complained that the cycle ran too hot on the initial ride home, but he was still able to motor down the 5 freeway in commuter traffic from near Saugus,( north of LA County), back to Laguna Hills, where he lives with his mother. He lacked the experience to have immediately turned the bike around and called out the Christian college Boy over the pegging water temp.
I had not expected to have to get down into such a mess with this particular engine and its problematic cam design history. But there I was in the process of removing the top guide, the oil lines, the cam holders/bearing caps, the sprockets, the cams, the chain guides and tensioners, in a search for a reason behind the mess he had dived headlong into for too high a price that June day, pulling me in after him. The constant complaint for the next month or more was that the '84 VF 500F ran hot. No complaints about performance or knocking to me, banished from my home and children some 57 miles away in the inland empire. Eventually he was told by a work friend that the VF sounded like it had wrist pin knock. He parked the bike and started bumming rides to school and work.
Now I was down on the garage floor checking and rechecking the valve timing in complete and utter surprise at what I was witnessing. The manner of checking was the method described in the only commercially published manual specific to the VF 500F: the CLYMER manual number N329, which covers Honda 500cc V4's, 84 through 86 . The method is to set up cylinder #1 at Firing TDC per the 1 and 11 o'clock cam lobe positions as seen on the VFR, cam lobes pointing to a place above the rear head's top chain guide and then getting the fine adjustment by checking the lines scribed on the outer edges of the rear cam sprockets per the manuals instructions, against the straight edge of the rear cylinder head cover gasket seal surface. To get the front cylinders in sync, the lobes of the #4 cylinder cams are placed at 7 and 1 o'clock, pointing away from each other, along parallel lines. this is done while the #1 rear cylinder is held in place at firing TDC. Again the fine adjustment of front timing is done by aligning the lines scribed on the front cam sprockets per the manual instructions, against the straight edge of the front cylinder head valve cover mating surface. Some idiot had seriously fxxked this '84 VF 500 up good and it appeared that Christian College boy had sold my son a bill of goods in order to palm this nightmare off onto my 18 year old.
The final insult. however, was discovered when the rear top cam chain guide was removed and compared to the front top cam chain guide. A normal top cam chain guide, when looked at from its long side, is straight. If you include the four feet that are used to attach the guide to the head using the 4 inner cam bearing cap bolts, it looks like a shallow "C" or like an elongated table whose legs straddle the underlying chain. The rear top chain guide had been purposefully damaged. The witness marks of where a circular flat end of what was probably a rod of sufficient length to allow it to be hammered down from above the line of the seat, was clearly visible in the middle of the back of the damaged guide. The circular witness mark was of approximately the same diameter as the width of the top chain guide. The tool used to disfigure the guide was probably a solid cylindrical metal rod of the aforesaid diameter. This had been pounded down into the middle of the top chain guide with sufficient force so as to bend what was intended to be a straight guide into one which, when looked at from the long side view, appeared like a shallow "M". The friction material applied to the underside of the top guide for the chain to wear against was disrupted, broken in twain and nothing but a knarl ,which acted to force the cam chain down for what can only be guessed was an attempt to take up any slack in an improperly installed cam, chain, chain guide and chain tensioner assembly. This disruption had been done recently, perhaps only a few miles before my son had driven the bike, for in no way had the profile of the double row of the chain made any inroad into the newly exposed friction material in the knarl. In all my years as a line and unit room mechanic I had never seen such incompetence and so obvious an attempt to defraud either a customer or a potential buyer with expediency and deception. Someone had taken a rod and hammer and pounded the chain noise away!
At that moment all I wanted was a nice thick brass or steel rod about 18 inches long and that christian prick's head to pound it into. I would sure have liked to turn what had been a round fat head into a soft and formless mass of pulp. But that was not all. All of the peering at the cam lobes had revealed that the cam lobes were damaged. They were pitted more than wiped. But they were ugly all the same.
The cam bearing surfaces in the heads were also damaged. There were obvious wipe marks on the cam bearing surfaces of both head's. The cam holder/bearing caps were also damaged. I did not have any plastigauge at the time or I would have checked the cam bearing clearances before writing this.
So, why have I bothered to write out this object lesson in human deception and venality? If Christian college boys studying for the ministry can justify cheating a kid, if he can justify lying about the condition of a motorcycle that he had been trying unsuccessfully for over a month or two to sell, if he is willing to doing something as dangerous as expose a cam chain on a motorcycle to a mechanical failure capable of causing a fatal accident just to gain a few hundreds of dollars, if he is willing to 'jimmy' the indicator of mechanical failure so that he can trick some naive high school kid into handing over his whole wad based on a child’s belief in the basic honesty of his fellow man, while this “brothers keeper” palms off his problem on an unsuspecting youth for over twice or three times as much as it is rightfully worth......In such a world what chance does anyone have? If christian boy can do that then I guess I'm justified in crushing his skull if my son dies as a result of the cam chain breaking as a result of his beating it into a M, causing the bike to fall and my son to die. Christianity be damned, and so it is, Christian college or no, it’s the law of the jungle everywhere, it's “let the buyer beware” taken to its cynical conclusion. I could always put the VF back together at the minimum cost and let someone else's son or daughter take the chance christian boy was willing to take on my son driveing his newly acquired teapot home that down a crowed commute time on the 5 freeway south. Money above principle, let the buyer beware!
He did not die as a result of a locked up crankshaft that day. But what can be done to salvage the situation as it now stands? The VF's cams probably have too much bearing clearance, and too much damage on the cams themselves. The Clymer manual says that in such a case you have to replace the heads and cam holders as units. If that is true you would necessarily have to replace the cams as well. That's well into $1500 for parts if you buy new ones. What good would it be to buy new heads and put some ground meat excuse for cams into the new cam bearings? Metal spray the old cams? Weld and regrind the cams? At what cost? Align bore the old cam bearings? Pay through the nose for some junk yard cams? What can I do to salvage this basket case my son paid $1500 for. Any ideas?

 

[object] cams
Think it's DageDodgeRacing and Colt Cams that resurface these (for larger vf anyway) maybe the rockers too
Still think there must b an undiagnosed reason for the guide abuse (adjusters ok?)

 

Thanks Gronk for the tips on rebuilding the cams.

Wish it could be that those pesky valve lash adjustment nuts and adjuster screws that might have pounded the rear cylinder cam chain guide into an "M" shape, but no such luck. The bastard that sold the bike took a rod and a hammer to it in order to tighten up the flailing chain and reduce the thrashing noise inside the head, or his "mechanic" did it for him. My concern is over the condition of the cam chains now. Considering the condition of the rear chain guide I think it might be necessary to replace the cam chains as well as the cams, the tensioners and the chain guides. But the biggest problem is getting my son interested in salvaging the bike. If he does not move on it his mother will start raging about it taking up space in the garage and it will be sold off as a basket case or for parts.

I hope to get him to write a thread about his VF 500 f dilemma. He should publish pictures of the smashed chain guide, the wear on the tensioners, closeups of the cams, and maybe some shots of the cam chain arcs, etc. He does not realize how much he might learn from making this mistake. That most of the time people learn more from making mistakes if they have to fix them themselves, mostly they learn how to avoid making them in the future.

 

I hope you and your son work this out. I remember 3 years ago my father told me not to purchase my 84 VF500 for $275. He told me, "Boy, are you sure?? You've never set cams in your life".

Well, he was right!! The cams weren't coming to the proper specs with the plastic gauge and I didn't have the proper gauges to do it the other way.

Well, I took my engine apart (just the heads) and put on new head gaskets because of the POS PO put them on backwards. Mixed up the cams, of which I don't think I still have them right and to top things off, he messed with the water pump.

Well, after fixing his wrongs by just taking the time and correcting them for $0 (besides the $30 a piece head gaskets) I now have a running VF500 with 7k on the clock that sounds pretty darn good!!!

Oh, and I tightened the cams to the lowest or midway torque values that are allowed by honda. Cause obviously, they were not going to be perfect.... : (

But the Cams sound really good. I don't hear any clunking or clicking that doesn't sound normal......Than again, I'm only use to SOHC or DOHC inline 4's. lol

It would be great if someone could tell me the wear limit on the cam chain buffers and tensioner slides???

Best of luck to you and your son to whatever you choose....they are really fun bikes!!

LL

 

I have a front cylinder head for an 86 along with all 4 camshafts. I would be willing to make you a deal on it if you are interested. I bought it for my bike [an 85] not realizing they changed the heads/cams between those years... Let me know if you are interested I can get you pictures if you need.

 

Hello Tj, I read through your long carb thread.

I am very curious about what the outcome was re the carb rebuild and the overheating problem. Was the boil over solved by replacing the cap or the thermostat "o ring"? We took the Thermostat out of the Vf and tested it. It was perfect. The overheating was due to the jumped cam timing on the Vf 500. Did you have a similar problem? Is that why you have the 86 cams and cylinderhead? If the story continues on another thread please tell me where it is located and its title.
As for our problem the obvious question is will the 86 parts fit on an 84 Vf 500 bike. I think the guys to ask are Jamie Daugherty. MasonV45 and Viff, the guys who answered your thread asking for help. One or all of these guys have the most experience with Vf 500's. I do have a Clymer manual for the 500 cc Vf models, it makes no mention of differences between model years, you are the first one to tell me that there was a cam change from 85 to 86. That would mean a definite change from 84 to 86 if true. I am interested in what you want for your parts. You could send me a PM if you like with a quote. I am assuming that we will need to find another 86 head to compliment the head you already have. MasonV45 is another guy who seems to know a lot about the Vf's. I'll ask them to wade in regarding using your 86 parts. Do you also have the the chains,guides and tensioners. I do not know if they are the same as those on the 84. Besides, ours are toast on top of the rear top guide that has been bent out of shape with a hammer and steel rod. Send me a reply on the price. Thanks again and keep me posted re your Vf 500, DKC

 

http://vfrworld.com/forums/first-second-generation-1983-1989/13144-help-me-my-vf500.html

i'm not sure if this is the thread you were talking about... but my engine is being completely redone now... As for the overheating it could have been a number of things but it is likely that the valves were a major problem as the rockers and cams were worn down so much... the rockers were actually indented instead of curved outward like they are supposed to be...

I thought yours said it was an 86 the 84 is the same as the 85 and in 86 they changed the heads and that is all. [that I know of]

Good Luck with the bike! Ebay was a lifesaver on mine... but you have to take some risks...

 

Yes, I read through your Thread of 2/28/08 "Help

"Help me with my VF 500!". I am still curious, did you ever re install the carbs and try to start the machine? It had been running very poorly, you sent a movie of the bike idling that gathered comments from both Daugherty and MasonV45 as well as some others. Did you ever run it again with the carbs rebuilt? There are so many variables with a long term project like yours turned out to be, that I can understand that by the time you got the carbs built and on again some other thing interfered and you just gave up in frustration and passed the engine on to a mechanic. Too bad, you were doing a great job hanging in there. I am sure that you learned a lot, but the sad part is that your final lesson was that you were not capable of getting it to run by your self, even with the help from the VFRW people. I wish I had been involved with the project, although I am not saying that your final decision would have come out any differently had I been.

I have been contacted by Jamie D and he has informed me that the 86 cams will work in our 84. He claims that I will need the cam followers off of the head too. I would like to know what you would sell them to us for. PM me with price or to tell me you don't want to sell.

Back to your cycle. I have a theory that no one has batted down yet. This past summer I nearly bought an 83 Vf 750 with terrible chain noise. Then my son buys the Vf 500 and drives it home running hot, drives it a month and tears it apart to find his cam appears to have jumped a cog or maybe two. Then I read about your bike and it is overheating like his. So I have formed the opinion that the chain driven Vf model was built to last and it has. But we are seeing what happens when a long lived Vf finally wears its chain tensioning system past its wear limit. Noise made by the loose chain running off the guide, the loosness finally allows the chain to slip or jump the crank sprockets, the cams go out of time,the engines start running hot and finally the engines overheat and loose a headgasket.

Next Vf you see for sale, if it runs see if it runs hot. A 10 to 15 minute run ought to do it. If it is hot, check the compression to make sure it has not lost a head gasket. Buy it cheap if it overheats and figure on replacing the chain guides when you get back to your garage and then driving it for another 20 to 40 K miles???? The important thing before you buy it is to drive the thing to see if it overheats. If it does not run its a basket case and should not be worth more than $300. The difficult thing when buying an old classic, like any Vf, is to figure out if it's getting ready to give up the ghost. If it overheats it's probably headed for the junk yard unless someone gets in there and fixes the cam/chain wear pronto. My 2 cents.

I hope you get your Vf 500 all sorted out and I hope your mechanic will tell you what he found inside it re the cam chain (s) and cams and the overheating problem. Would you tell the rest of us what he figures caused the problem(s)? I think we would all like to know.

 

Makes me all that much happier that my 750 has gear driven cams.:smile:

 

Maybe I tend to give people the benefit of the doubt, but I'd be just as likely to believe that this seller was totally mechanically ignorant, and actually believed that his mechanic was doing it right. My MO tends to be 'buyer beware' (I made some similar bad decisions at that age) but have you given the PO the opportunity to buy it back from you, or to split the costs of repairing it properly? If he really didn't know and you bring it up in a non-accusing manner you might be surprised where you get.

One to throw out to the guys who know the F1/F2's but will a gear driven VFR engine or a Magna engine fit in the VF500 frame? Might be a good time to get into a 'new' 700/750 engine. I see them locally from time to time and on ebay as well.

S

 

the VFR engines will not fit into the older 500 vf and the complete magna motors will not either as they are shaft drives but some internal parts will work.

 

So much for that idea.

Tough call, when you'd need to spend more to fix a bike than its market value. Maybe someone has a mechanically sound crashed parts bike??