VFRBert Posted January 2, 2014 Share Posted January 2, 2014 heh, heh,....he said "modulus". Sorry,sometimes i am so busy translating english words into Dutch, i miss something. Especially tech words. Valve springs can get weaker in time, low spring pressure may cause breaking plunger rods, so maybe it may also be the cause of the problems with the vf engines. I am reading on a Dutch tech blog and one of the causes of loss of valvespring pressure is overrevving. Overrevving is mentioned earlyer in this trhread as a probable cause of the breaking valve stems. Choose English to read:http://track-techniek.blogspot.nl/2011/12/klepveren-1-hoe-en-wat.html Google possibly will make a bit of a mess, but it will be readable. Link to comment Share on other sites More sharing options...
Member Contributer InvisibleCities Posted January 2, 2014 Member Contributer Share Posted January 2, 2014 Thanks for the update. If I could ask, how are the cams and followers? This is usually the start of the trouble. Link to comment Share on other sites More sharing options...
timmythecop Posted January 2, 2014 Share Posted January 2, 2014 Youre Ok Bert. My NL is horrible. I just really like words like that! Link to comment Share on other sites More sharing options...
jeremyr62 Posted January 3, 2014 Share Posted January 3, 2014 Fatigue and elastic modulus are completely different. Fatigue is about the initiation and propagation of cracks. The elastic modulus is a number that represents how easy/difficult it is for atoms to move from their equilibrium rest positions in the crystalline lattice. The elastic modulus of steel is about 200GPa and really doesn't change very much at all. Springs don't get weaker over time unless there is some mechanism that softens the steel. Here we are considering the strength of the steel though, not the stiffness. What most peolpe mean when they say a spring gets "weaker" is that the spring has taken on a permanent set. This means it has been stretched or compressed beyond its elastic limit. Hence if a spring is within its service limit then it is OK to use because it hasn't been overloaded too much. If a spring fails by fatigue this generally means the spring fractures. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted January 3, 2014 Member Contributer Share Posted January 3, 2014 Hmmm probably never know... Nice one posted in Craigslist Atlanta with what the owner thinks is a rod knocking. Link to comment Share on other sites More sharing options...
Guest Posted January 4, 2014 Share Posted January 4, 2014 Mine is for sale, check the classifieds. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted January 4, 2014 Member Contributer Share Posted January 4, 2014 Nice one and I hope you used the valve adjusting trick posted here where you use two feeler gauges to adjust both valves at the same time and then rotate the motor until the valves tighten and then lock down the locking nut so as not to let the adjuster nut to move. Link to comment Share on other sites More sharing options...
Guest Posted January 4, 2014 Share Posted January 4, 2014 I did indeed use the two feeler method and made sure that the adjuster did not move while tightening the lock nut, rotated the crank through several cycles, rechecked. Link to comment Share on other sites More sharing options...
Member Contributer InvisibleCities Posted January 4, 2014 Member Contributer Share Posted January 4, 2014 Mine is for sale, check the classifieds. Say it isn't so! ;-) (wish you the best on the sale & a shout out for being such a great 500 aficionado) Link to comment Share on other sites More sharing options...
Member Contributer tbzep Posted January 4, 2014 Member Contributer Share Posted January 4, 2014 If you were a bit closer and your bike was an '86, my "boss" would let me buy it. We met and dated and even honeymooned on my '86. Link to comment Share on other sites More sharing options...
Guest Posted January 5, 2014 Share Posted January 5, 2014 Say it isn't so! ;-) wish you the best on the sale & a shout out for being such a great 500 aficionado) Thanks, much appreciated. I'm doing this a bit reluctantly, but things change....time to move on. Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted January 6, 2014 Author Member Contributer Share Posted January 6, 2014 Right now I am waiting for a salvage auction on a VF500 to come up. It's smashed front and back, but it's a runner, and after looking at the past history, should go for <$100. Then I'll have a spare 85 head for someone else to use. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted January 6, 2014 Member Contributer Share Posted January 6, 2014 I did indeed use the two feeler method and made sure that the adjuster did not move while tightening the lock nut, rotated the crank through several cycles, rechecked. Link to comment Share on other sites More sharing options...
Member Contributer JeffInFranklinTN Posted January 22, 2014 Member Contributer Share Posted January 22, 2014 I do not have one shred of proof that the reply I'm about to make is true but, I have heard comments about the 84/85 500F's having serious valve failing issues. (heads breaking from the stems as seen in the pic posted in this thread) They usually would fail between 20,000 miles and 25,000 miles. It was the materials used in the metals to manufacture the valves that had made the valve stems weak. Honda addressed that issue in the 86 model, The coolant, hoses and thermostat housing are larger than the previous 500F's and the heads themselves are lined bored and I believe will not fit onto a 84/85 engine. I also believe that the engine to frame bolt hole patterns are all identical for all three years. So you should be able to fit an 86 engine into an 84/85 frame. I also heard that the 500 Magna engines and 500 Interceptor engines will interchange. The gear ratios are different between the two however. I have a 1986 VF500F. It currently has around 24,000 miles plus. It has seen the rev limiter a time or two but not since I heard about the valve problems. Fingers crossed she lasts a long time. Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted January 22, 2014 Author Member Contributer Share Posted January 22, 2014 Considering how both the 85 and 86 had the same failure (albeit on different scales), not sure they really fixed anything. The head on the 86 is different than the 84/85, and the part numbers are different, but the valves are still the same, and the springs. The site hosting the auction I was waiting on got bought out, so I guess I'm not getting the easy way out of just buying a running engine for cheap. Link to comment Share on other sites More sharing options...
Member Contributer InvisibleCities Posted January 24, 2014 Member Contributer Share Posted January 24, 2014 ^ To clarify - intake/exhaust valve and inner/outer valve spring part numbers are different btwn the '84/'85 and '86. Link to comment Share on other sites More sharing options...
Member Contributer JeffInFranklinTN Posted January 24, 2014 Member Contributer Share Posted January 24, 2014 ^ To clarify - intake/exhaust valve and inner/outer valve spring part numbers are different btwn the '84/'85 and '86. There's hope after all!! :smile2: Link to comment Share on other sites More sharing options...
Member Contributer InvisibleCities Posted January 24, 2014 Member Contributer Share Posted January 24, 2014 VF500Fs are great bikes. This said all years can develop valve train issues - or not - depending a bit on the luck of the Irish. Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted January 24, 2014 Author Member Contributer Share Posted January 24, 2014 I also just noticed that the valve guides are different for the intake and exhaust. Didn't realize they would be, and not entirely sure what the difference would be. KPMI did get back to me about springs. They gave me the info that I would have to send them for them to look at new springs. Maybe this weekend I'll get around to that. Link to comment Share on other sites More sharing options...
Member Contributer InvisibleCities Posted January 24, 2014 Member Contributer Share Posted January 24, 2014 KPMI did get back to me about springs. They gave me the info that I would have to send them for them to look at new springs. Maybe this weekend I'll get around to that. Good deal! Link to comment Share on other sites More sharing options...
Member Contributer Kel Posted January 24, 2014 Member Contributer Share Posted January 24, 2014 Hey Jeff, that sig picture's a little big wouldn't you say? EDIT: Much better...bike looks great by the way. Link to comment Share on other sites More sharing options...
Member Contributer JeffInFranklinTN Posted January 24, 2014 Member Contributer Share Posted January 24, 2014 Hey Jeff, that sig picture's a little big wouldn't you say? EDIT: Much better...bike looks great by the way. Sniffle, I had cropped it but I was still concerned about the size of that pic but the back ground really makes that pic and couldn't see hiding that part of it. Got a private message from another member about it also. It's okay no problem I understand....I GREATLY appreciate the politeness from you gents. :) Thanks for the compliment. I love that hot little yellow thing. My girlfriend caught me with my arms wrapped around her fuel tank the other day. She almost teared up with heart break. Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted May 13, 2014 Author Member Contributer Share Posted May 13, 2014 Had an hour to spare this past weekend. I picked upthe head from a guy who did the repair work. Fairly happy with what I got. Charged me a bit more than I thought, but he also took care of a lot of tedious work (like cleaning all the remainder head gasket off and cleaning up the surface a bit). Here's how I got it back. He recut all the seats on the damaged side of the head. The valve that is in there is a brand new one. He didn't want to file away too much of the head material, so it's cleaned up enough where there aren't any bits that may break off. Better than it was, and nothing is interfering with the valves. This was the valve guide from the very broken valve. Dirty nasty seat. Cleaner looking seat. Still has some pitting, but considering how this side of the head held good compression, I'm not going to be too worried about it. Would have been nice if he just cut all the seats, but now we're just being greedy. Valves clean right up as well. Found one more bad valve (intake valve on the busted side). Good thing I had a couple spares from another head. Next step is going to be cleaning the head out to make sure there isn't any lapping compound still around. Last thing I want is the guides to start wearing away due to me being lazy. Link to comment Share on other sites More sharing options...
Member Contributer Kel Posted May 13, 2014 Member Contributer Share Posted May 13, 2014 I love your tenacity. You truly have bike blood in your veins. Most people would have run for the hills by now. The time spent on stuff like this, as much of a pain that it can be sometimes, is part of the hobby and separates it from merely transportation. Keep it up. Those rough areas near the valve will cause the charge to swirl, giving you a better burn and 20 more HP. Link to comment Share on other sites More sharing options...
Member Contributer InvisibleCities Posted May 13, 2014 Member Contributer Share Posted May 13, 2014 ^ +1 Way to Go! Link to comment Share on other sites More sharing options...
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