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What can you tell me about my VF500?


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11 hours ago, Mohawk said:

inlets often recede into the head thus tightening the clearance & exhaust valves often loosen due to increased wear with the extra heat. Thus inlets can be set on the looser end of the adjustment scale & exhausts on the tighter end, meaning over time they will even out & allow you to extend the clearance interval !

 

Thanks for the info! I assumed the adjusters would only loosen. I almost left the inlet valves too tight. I will also check the ends of the tappets.

 

As far as the condition of the valve and runaway adjuster goes, I think everything is as it should be. I'm not sure what a missing valve stem looks like. All I can see is what you can see in that picture. The caps of the springs are on there, and I can see the valve inside.

I think the valves are going to be good to go once I adjust them, but now it is time for another bombshell...

 

 

 

 

Fork Shortening?

 

I am a vertically challenged person and I've been figuring out ways to lower this VF500. So far I have re-shaped the seat to make it narrower and lower. I've fitted lower profile tires for a handful of cm on both sides. My next target is the suspension itself. The first logical way to lower the suspension is to slide the forks up the triple trees. I've decided I will do one inch here. This leaves two more options: altering the rear linkage, and shortening the forks internally.

Here is my plan:

PA260338.JPG

 

This is where the 5.5 inches of suspension travel comes from. This rod bolts onto the bottom of the fork slider. When the suspension compresses this piece moves inside the fork tube, pushing the fork spring together. If I make a spacer and put it in front of that stopper spring it will lower the initial height of the fork. It will do this by sacrificing suspension travel, it will move the slider up further on the fork tube. This means when fully extended and under no compression the fork will be shorter. 

 

The downside of doing this will be a stiffer ride. I want to make a 1.5 inch spacer. If I shorten the forks this way the fork spring will stick out of the tube 1.5 inches more than it is supposed to. If I can compress the spring into the tube, without cutting it shorter, and bolt it back together it will maintain the stock spring rate and dampening. The only other thing I need to worry about is the rake and trail of the bike. I can make longer links for the swing arm, effectively lowering it. Alternatively I can send the doglink off to be modified( Wider angle = lower ride).

 

My questions are: Has anyone done this before, do you have any advice? Do I need to modify the slider bushing?(See second picture) Should I disable my TRAC system?( I read something about this in Dutchy's build)

 

PA240325.JPG

 

The parts in this picture are from top to bottom: Circlip - Fork seal - Backup seal - Slider bushing - Tube Bushing - Piston(As seen above)

 

If you need help visualizing what this mod will do. Imagine the piston in the picture above is slid further up into the fork tube. Ta da, the forks are lower.

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Can't help you with the lowering i'm afraid.  Fitting the RaceTech emulators called for removing the TRAC stuff (and drilling large oil holes), so that is what I did.

 

 

One thing i can think of is that you relocate the claxon for that might start to hit your fender.

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If you want shorter forks, just restrict their full length. You have the top out spring on the damper rod, so if you want 1" shorter forks at full extension, then simply add a 1" thick spacer above the top out spring on the damper rod, This will stop the fork expanding to full length, but you will lose 1" of suspension travel.  Or alternately find some shorter stanchions (the chromed leg) of the correct diameter.  Most forks from a manufacturer have the same thread on the top, so Honda used Showa exclusively in that period. I have swapped Kawasaki & Honda fork tops from Showa from bikes made 10 years apart, same thread !

 

For the rear start by letting the air out of the shock, then add a travel limiter to the shock or add a lowering suspension link, but that might be hard to find for the VF. Other models may have a suitable link to use.

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Catastrophe.

Absolute cataclysmic failure.

The intake valve that was missing the adjuster is %100 snaffu. I learned in my attempts to re-insert the adjuster, that the valve stem has fallen out of the keepers. I just finished trying to reattach the valve stem to the keepers by pulling it up with a coat hanger and simultaneously pushing the top of the valve spring down. I'd like to think of this as open heart surgery on a motorcycle. Spoiler alert. The patient died. What happened is, one of the valve keepers popped out of the top of the valve retainer. That's not too bad, until you consider it fell down the abyss that is the center of the engine. Right down beside the cam chain. I am trying to source new valve keepers in the mean-time until I can pull the oil pan off and look for this thing. Even if I find a new valve keeper, my plan obviously is not going to work.

 

Why did the valve fall out of the keepers? How do I get this all back together? Do I need to pull the entire top half of the engine apart in order to get at this single valve?

When I was doing this I got the valve stem up above the keepers a few times, but it didn't click in or anything

 

If I cant figure this out, I am considering just having a V3 interceptor.

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Lisle valve tool is your best friend..

 

I already was a bit surprised the valve keepers were still in there.. The valve keepers are held in place bij the spring retainer. Normaly the valve is pushed on the centre of the stem and because the valve retainer is concave its holding everything together.. Without the adjuster installed on the rocker arm, the rocker arm is pushing down on the retainer and not on the valve stem, causing the valve keepers to out of the groove on the valve stem..

 

The vid shows how to use the lisle valve tool on a valve with the cilinder head removed.. To use it on a engine it is a bit more tricky. Some use compressed air on the cilinder to keep the valve in place, but you can also run a (greasy) cord down the spark plug hole into the cilinder and manualy turn the piston towards TDC. Make sure you don't run the whole cord into the ciliinder but keep one end out to remove the cord after the job is done.. The cord wil keep the valve in place.

 

The guy is using a hammer, but from my experience, usualy pushing it by hand is enough to get the keepers out and for sure getting them in..

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I have no idea how to do it without pulling the head. If you can do it with keeping the head intact, it is the way to go, as OEM head gaskets were hard to find, and not sure about aftermarket. It gets even better when the head gaskets went through different revisions for different year engines.

 

I probably have some extra parts from my rebuild worse case. Are you sure the valve is good?

 

Some from one of my engines. PS. Don't bother buying another engine. They are all bad.

20161101015318-50dd5e51-sm.jpg

 

20161101015319-148c5f41-sm.jpg

 

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There is this. I have it and I am evaluating it at the moment. When I know it works for the line bored VF500 I will post my findings.

I bought it as a way of checking the free length of the valve springs to try to work out if these really are the weak link causing the valves to drop.

 

http://www.ebay.co.uk/itm/Honda-ALL-VF500-VF700-VF750-Valve-Seal-or-Valve-Spring-Replacement-/121942988658?hash=item1c645e5772:g:DuQAAOSwGOxW~xFc

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It is nonsense to suggest all VF500 engines are bad btw. There are many reliable high mileage examples out there. I will agree they need much TLC but if looked after they seem to be OK. I have three engines and they all work (so far).

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I like the look of this tool designed for the V4 engine. I will certainly use the rope trick instead of hooking a coat hanger through my spark plug. I look forward to hearing how it works for you Jeremy. As for Lisle tool vs. Baxter tool, so far it looks like the Baxter is doing better since you don't need to remove the rockers. I am interested in what you guys think is better; Lisle or Baxter?

All I can say for the state of my valve is that light doesn't seep through when I shine a flashlight into the cylinder. 

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I have tried it on one of my VF500 engines. The pictures of the installed tool are here.

https://goo.gl/photos/8n2YNFH5r8Z5gMmX6

It works really well when removing the collets. The force required to compress the spring in the VF500 is really not a lot. When you see the springs then you can see why. The inner spring is shockingly spindly. Which might explain why they take a permanent set after high RPM abuse and exhaust valves drop. However, contradicting this is the fact that the one set of springs I removed from an engine that had 37,000miles were all to spec and way above the service limit. I know nothing about the history of this engine. It was from a spares bike I purchased. 

 

The downside to the tool is the fact that I found refitting the collets extremely time consuming and difficult. The tool does not fit on the collet retainer square, so the spring is pushed down at an angle which makes the space around the valve stem unsymmetrical. However by judicious spacing of the initial collet and serious compression of the spring I did manage to get them back. I would be concerned that I might be over compressing the spring past its elastic limit. I will take out the springs I refitted to see if I have damaged them. If I have given them a permanent set then the tool is useless.
 

 

 

 

 

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I'd have to measure the springs again to see if they were in spec. but the springs varied a lot.

 

20161105041238-872fd37b-xs.jpg

 

20161105041238-6b033366-xs.jpg

 

It would be great if there was a full rebuild kit for the VF heads, but with all new valves, springs, gaskets, guides, seats, ect, that would be 2x as much as the bikes are worth. But with how many of these engines went south, there would surely be some demand. Can't say I know of a more powerful 500cc engine off the top of my head.

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I have only measured two springs so far so I might see the variation you did. That's the job for this weekend.

I too wish the springs and valves were available but it will never happen. You are right about the output. Even accounting for Honda overestimates the VF500 was a powerful engine with no modern rival AFAIK.

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Wow!. If that's true then that's an amazing find. Be interesting to find out how much. I think the springs are the same between all model years so while they say 84-85 I am pretty sure the 86 springs are the same. The valves are different though AFAIK.

 

 

Back to the tool I have been using, refitting the collets does get much easier with practice. You need a degree of finesse but you need that anyway working on these engines. I checked I wasn't damaging the springs by over compressing them and I have not changed the free length so all is good.

 

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Used a less "gentile" method while disassembling redslut completely (and permanently...).

Am sure some damage was done, so not advised!

 

 

clickerdiclick

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  • 2 months later...

I need some advice on my valve issue. An acquaintance of mine who is mechanically adept looked at my engine today and he thinks its possible that the valve was bent. The theory being, why didn't the valve drop inside the cylinder and explode? Either luck, or it was bent when it fell out of the keepers, lodging it in the head. I have yet to buy a tool to fix the valve, I am going to try and build my own first. What I am wondering is how do I tell if the valve is bent once I hook it back together? Where do I get replacement valves if it is broken? Also is it possible to remove the rear head without removing the engine, and another issue, is a seized exhaust valve enough to make the cylinder misfire? If not, I've got to figure out what is.

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I don't have brand new valves in stock, but for a replacement, I do have a pile of VF500 valves that are still useful... Just shoot me a PM...

 

A bent valve, once removed from the engine, is easialy recognezed if you put it in a drill.. If the head of the valve wobbles when you turn the drill, it's bent..

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sorry to hear of your troubles, I've been there and done all that with a dropped valve after rebuilding the heads.  Anyway, you must pull the engine.  If you're going to try to keep this bike alive, you might as well learn how to do that well.  I'm pretty sure you can pull the front head with the engine in but the rear one is really tightly in there.  Besides, the rear, top engine mount is part of the rear head sooo... it's just so much easier working on a head without having to maneuver around the frame trying to find the best angles to hook up wrenches or anything.  

 

You can still buy new valves, they are pretty easy to find (partzilla, ebay, many places still carry them).  Luckily the exhaust valves for the 84-86 are all the same, the intakes did change in 86 though.  If your valve was bent then your guide is probably trashed and putting it back together with a trashed guide will not last very long so you'd have to have a new guide installed.  A machine shop should be able to help you with that along with cleaning up the seat for a new valve.  You'll be relegated to aftermarket head gaskets as well, there are no OEM's out there that I know of.  Plenty of aftermarket stuff though, they've worked fine for me, I just found that torquing them (and re-torquing after a couple hundred miles) just a little over spec works best, otherwise you might get a little coolant seepage on the edges...   Here's a thought:  if you have no real love or commitment for one of these, it's my humble advice to look elsewhere for riding an old(er) bike.  Pick up an 87 of some type or younger...  the headaches will seldom cease with one of these.  The only reason I keep mine alive is that I bought it new when I was 18 and I'm almost 52 now.... so it's just part of my life.  Best of luck, you'll most certainly need it.  

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On 11/5/2016 at 5:24 AM, YoshiHNS said:

Well, I found a company that has a spring kit for the VF500 while looking through custom trellis frames.

 

http://www.rdvalvespring.com/index.html

 

Under spring kits, honda, bottom of the page. Worldwide dealer network.

Just as an FYI... I bought the 84/85 kit (dual springs, retainers, cotters, spring seats) for just little over $800 (USD), they looked great but were not the right size, too tall and too wide. The owner refunded my money promptly, apologized and asked that I send him some old samples and that he'd have them ready for me in about 2 weeks.  I just elected to go with some springs I got from CMSNL NOS last year instead.  They only had about 1500 miles on them before a valve broke/dropped.  Anyway, doing a complete and correct job on the heads alone with new springs, valves, guides, retainers, cotters, valve stem seals, head gaskets, various o-rings, machine shop labor, etc easily exceeds the value of even a mint entire bike.  Not cost effective by any means but if you want to ride one as reliably as you can afford, it'll cost you.  

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  • 1 month later...

It was fairly warm, here in Canada, today and I put a few hours into trying to solve my valve issue. I have concluded that the valve is indeed bent. I made an air compressor adapter for the spark plug socket to try and push the valve up with air. It did not budge. I am weighing the options right now. Should I undertake removing my entire engine to replace this valve? What will a new valve and/or possibly machining cost me? What are the consequences of running my bike with 1 exhaust valve always slightly open(besides the fact that this cylinder is not working)? Is there an easier way around this for the time being? I want to ride this bike, this summer.

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The bike will run like sh1t if that valve does not close. Not an option IMO.

My advice is try to get another running engine. They are pretty plentiful over here although I have no idea about Canada. That way you just transplant it in and you then your OE becomes a donor for parts. I agree with Jrodrims27 though. It has to be a labour of love with these bikes now. A later VFR is a much more sensible bike to own if you are going to rely on it.

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Option one: Get a used valve and lap the surface to match the valve seat..

 

Option two: get a good used replacement on the cilinder head..

 

I do have used valves... I do have complete heads with lapped valves and new seals installed..

 

I killed two engines on the conrods done to racing. But both engines had their head work done.. They are good..

Let me know if interested.. ( A whole head would be a killer on the shipment costs i think) 

 

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I do not want to give anybody the impression that I am a person who half fasts things. Right now I am just not able to do everything I wish I could for this bike. Whether it be not having the time, money or expertise. I want to learn though and I am giving what I can afford to do this. I am looking into sourcing a new engine. Does anybody have any advice this time around so that I can find an engine that works the first time?

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Take your time. Get the engine from someone who seems trustworthy and try to get an 86 with the mods Honda made, although if a good 84/85 comes up don't let that be a show stopper. You get claimed low mileage engines on Ebay every so often. You have to be able to work out why the bike was broken in the first place; you can usually tell by looking at the other VF500 parts the breaker will be selling.

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