Cam lobe flattening '85 VF500

[tinkerinWstuff]

Pulled the valve covers off and found the #2 cylinder intake valve lobe is flattening. I can feel scoring on the top of the lobe and the thing has a flat spot right where the peak should be.

Valve gap for one of the intake valves on the same cylinder was also out of wack. Doesn't appear that anything is screwy so I'm hoping it's just messed up from a previous backyard mechanic.

[JamieDaugherty]

That's the dreaded top end issue. Keep in mind that the cam lobe is actually the second thing to go - the rocker is the first. If you pull the cam you'll find a large divot in the rocker face, that's what has caused the damage to the lobe. It's also why the clearance is bad.

Many people think the VF500 is immune to this problem. It's not, as you can attest to! I've also personally seen VF500's with bad rockers so it's very real.

[tinkerinWstuff]

That's the dreaded top end issue. Keep in mind that the cam lobe is actually the second thing to go - the rocker is the first. If you pull the cam you'll find a large divot in the rocker face, that's what has caused the damage to the lobe. It's also why the clearance is bad.

I know the previous owner replaced a cam in the rear cylinders (1/3) but I don't know if he did anything with the rockers. Suggestions?

Many people think the VF500 is immune to this problem. It's not, as you can attest to! I've also personally seen VF500's with bad rockers so it's very real.

That's what the local Honda dealer told me. Not the guy who sold it to me but the dealer I went in to buy parts from.

[JamieDaugherty]

I know the previous owner replaced a cam in the rear cylinders (1/3) but I don't know if he did anything with the rockers. Suggestions?

You'll need to pull the cam(s). Bear in mind that I'm not sure if the rockers are available anymore from Honda. Parts availability is a problem. Megacycle used to hardweld the rockers for the V4's but I'm not sure if they still do.

[tinkerinWstuff]

So I did a compression test today to see how healthy the rest of the motor is. They are within 10% but less than impressive since my clymer manual says 142-196psi (sea level). I am at 5000ft but I wouldn't think that translates to 30psi drop - maybe for fun I'll have to go to matt's hijacked thread that turned into a technical thesis on compression ratios.

Won't pouring a little oil in the cylinders tell you if it's rings or valves?

#2 110psi
#4 100psi

#1 105psi
#3 110psi

It's a brand new guage too so I suppose it wouldn't hurt to connect it up to my air compressor to see if the pressures measure similar. Not having another guage to compare too, that's the only way I can think to verify the guage reads right after the trip from China.

[tinkerinWstuff]

It may also be important to note that my compression test is on a cold engine.

With a little oil in the cylinders the compression values jumped 30-40 psi.

P.S. the tester came from Tiawan, not China

[magnavmx5]

compression should be checked on a warm motor man given that it went to 150 someodd cold i think you are probly making a good seal. Wich means your rings etc are good and the valves themselves are sealing. This has nothing to do with your cam showing irregular wear as only a wrong indexing of the cam would cause sealing issues without damage to the valve seals themselves.

[tinkerinWstuff]

This has nothing to do with your cam showing irregular wear as only a wrong indexing of the cam would cause sealing issues without damage to the valve seals themselves.

yep, I know. I just wanted to make sure there weren't any other issues with the motor before sinking any more time, effort, and dollars into it.

The bike is significantly tore down, I removed the carb assembly to fix a float problem and replace the cracked carb-to-head insulators so I couldn't do the test warm without a significant about of effort.

I'll consider it fine, especially considering they were within 10% of eachother and worry about the cam lobe issue.

[JamieDaugherty]

....and worry about the cam lobe issue.

You should think of it as a rocker arm and oiling system issue. The cam lobe is a secondary effect/failure.

Let us know what you find out!

[GreyVF750F]

Shows rockers still available here: http://www.shspowersports.com/fiche_...1985&fveh=3905

[Alaskan]

Where is squirrelman at a time like this!!????!!!!!!

[NorcalBoy]

Where is squirrelman at a time like this!!????!!!!!!

I believe he has grown battle weary from the collective trouncing him for his unpopular truthfullness.

[magnavmx5]

yeah i got lucky and replaced all of mine with nos parts when i saw i had wiggle room. I figured it was just sop though given how small that shit was.

[JamieDaugherty]

Shows rockers still available here: Honda Yamaha Suzuki Kawasaki Sea-Doo Can-Am Ski-Doo Motorcycle Parts ATV parts Scooter Parts personal watercraft parts Accessories

Just because an online source shows them as available does not mean they are. You really need to go to your local dealer and have them check the warehouse inventory level. Since you are already there, order the parts from them - they can beat an online place every time.

[tinkerinWstuff]

can you point me in the direction of a previous thread on this issue that applies to the 500? I'm sure this topic has been beaten like an Iranian election protestor....

[JamieDaugherty]

can you point me in the direction of a previous thread on this issue that applies to the 500? I'm sure this topic has been beaten like an Iranian election protestor....

There's not really a thread dedicated to this topic specifically for the 500's. That's because dropped valves dwarfs the top end oiling situation on the 500's. Once again, you can attest to the fact that it exists on the 500. Do some general searches for "V4 Honda top end oiling" and you'll find more info than you can shake a stick at. HOWEVER - keep in mind that much of what you will find is either misleading or just plain wrong. The problem is two fold:

1) The rocker arms were not case hardened deep enough
2) The oiling to the top end is insufficient

All Honda VF's made prior to 1987 had this problem without exception. Some false information you'll find is people making claims that their particular model is not affected. What makes me chuckle the most is the line-bored cams claim. It doesn't address one of the above two sources of the problem, so it's not a solution. A good example is the VF1000R which has line-bored cams but have rockers go bad quite often.

Your course of action is, obviously, to replace all of the damaged components. You can choose to ride it like that and hope for the best or do something about it. The "do something about it" option pretty much is one thing, and that is modification of the oiling system to the top end.

Here is a link to some old content from my site showing an example of what that looks like:

The VF1000F Project Page - Top End Oiling System Modification

[tinkerinWstuff]

Thanks for the link Jamie. I'm sure I'll have more questions to come but I'm camped out on the couch today with a touch of a cold/flu and watching NASCAR.

[GreyVF750F]

Just because an online source shows them as available does not mean they are. You really need to go to your local dealer and have them check the warehouse inventory level. Since you are already there, order the parts from them - they can beat an online place every time.

This is a Honda Dealer in Grand Rapids, MI. They use the Honda warehouse. Also they use other Honda part locations that don't show up on line. If you order on-line and the parts are not available they will cancel your order with in 24hrs and credit your card. Or if you really need it now you can call ROBERT KERN, INTERNET SALES MANAGER, SHSPOWERSPORTS.COM at 1-866-829-6884. He will gladly work with you checking first. Plus you usually get the parts with in five days! Sure beats driving around and having to deal with a parts guy that may not care much about older bikes.

Two of my local Honda shops one 8 miles another 23 miles away don't want to beat on-line places. They tell me they don't make money that way. Go figure. Good luck no matter how you do it.

But remember all that ground down metal had to go someplace. Guess where? I wonder what your bearings look like? Embedded with little metal particles I bet. You need to pull your motor all apart to just clean all that out and have a good look at a few bearings. Might be cheaper to find another good running one.

[tinkerinWstuff]

But remember all that ground down metal had to go someplace. Guess where? I wonder what your bearings look like? Embedded with little metal particles I bet. You need to pull your motor all apart to just clean all that out and have a good look at a few bearings. Might be cheaper to find another good running one.

that's comforting

[GreyVF750F]

You don't want to hear this either. I got thinking later that, those metal particles would really like to stick to the stator. Then I got thinking about the transmission's bushings and ball bearings and clutch.

Sorry

[JamieDaugherty]

If you order on-line and the parts are not available they will cancel your order with in 24hrs and credit your card.

Exactly. The online part of the equation makes it impossible to know if the warehouse has inventory. Honda's parts system is a little screwy, but it's getting better.

Two of my local Honda shops one 8 miles another 23 miles away don't want to beat on-line places. They tell me they don't make money that way. Go figure. Good luck no matter how you do it.

I get a permanent discount (I'm setup in their system) at my dealership. When you factor in shipping they always beat online places. And guess what? They are making money by selling me parts. It's really handy for them when I walk in and go behind the counter and enter my own order into the computer too. It's sort of like Norm on Cheers actually.


tinkerinWstuff - The idea of metal pieces floating around is not really something you want to think about, I understand. However, that's what the filter is for! I've had several V4's with top end issues and have never seen collateral damage that I could trace back to pieces of the rockers and cam lobes.

[GreyVF750F]

tinkerinWstuff - The idea of metal pieces floating around is not really something you want to think about, I understand. However, that's what the filter is for! I've had several V4's with top end issues and have never seen collateral damage that I could trace back to pieces of the rockers and cam lobes.

Wow that's scary. If you look at the oil system diagram you'll find that the only oil that is filtered is going to the mains and rod bearings. The rest of the oil for the trans,cams and piston rings is unfiltered! Also not knowing if the filter went in to by pass mode (no filtering) at anytime you really don't know what those bearings are like. Those small metal particles does an oil pump wonders let alone the other parts of the engine.

As Dirty Harry asks, do you feel lucky, well do ya? How long do you want to keep this bike running? The only way to tell is to take the motor a part and have a look see and at least clean it out. Having metal particles still in there after all that work and money is really back yard IMHO. Good luck.

[JamieDaugherty]

Wow that's scary. If you look at the oil system diagram you'll find that the only oil that is filtered is going to the mains and rod bearings. The rest of the oil for the trans,cams and piston rings is unfiltered!

FYI - there is no oil going directly to the piston rings. They only get indirect splashing which comes via the filtered portion. Since there is only one pump and most of the flow goes through the system you can figure it all gets filtered.

Having metal particles still in there after all that work and money is really back yard IMHO. Good luck.

As previously mentioned, I've had a bunch of V4's and several have had top end issues when I got them. After repairing the top end , I later on split the cases on a couple of them for other reasons (gearboxes, mainly). I found no damage what so ever from "metal pieces floating around. I'm not saying that it's impossible, just not likely.

Seriously, you are better off with new oil and filter than opening the Pandora's Box that comes with pulling down an engine that old. You would likely run into parts availability of some sort. You call it a risk, but I feel that it's a very small one.

[tinkerinWstuff]

Thanks for the debate. If I was planning on restoring the bike for my own pleasure and years of riding then I might consider digging into it further. But as it is, I'll end up riding it for a few months and then selling it to one of the local college kids for $1200 as a starter bike.

I haven't been able to touch the project for the last couple days as I was hit hard by the flu. Hopefully before the week is out I'll feel well enough to get to the salvage yard for the rockers and cam.

Jamie - should the local Checker/Champion/Napa be able to supply the braided lines, banjo bolts etc...

Also, is there a check valves in the bottom of the line to keep them from draining back at shutdown or does it pump up fast enough not to worry about?

[JamieDaugherty]

Jamie - should the local Checker/Champion/Napa be able to supply the braided lines, banjo bolts etc...

It's more complicated than just building lines. Whatever you make would have to be checked to ensure that the bottom end pressure is not affected and that there is enough oil going to the top end. The latter is not much of an issue with a main oil gallery type mod, but the system design is not a "no brainer".

Also, is there a check valves in the bottom of the line to keep them from draining back at shutdown or does it pump up fast enough not to worry about?

There is no check valve in the oiling system to the top end. The stock system does not pump up very quickly, that's one of the problems.

[tinkerinWstuff]

The link you provided that shows what the mod looks like, has an embedded link to the "performance page" that is supposed to have info on the kit. But I can't find it....

[JamieDaugherty]

The link you provided that shows what the mod looks like, has an embedded link to the "performance page" that is supposed to have info on the kit. But I can't find it....

As mentioned, it's a page from my old site that I've posted back to the server just for reference use. The current content of my site is at Daugherty Motorsports - Motorcycle Suspension Performance and Modification .

[tinkerinWstuff]

As mentioned, it's a page from my old site that I've posted back to the server just for reference use. The current content of my site is at Daugherty Motorsports - Motorcycle Suspension Performance and Modification .

So are you saying you don't sell the mod any longer? Because I was all over that site and couldn't find it. Lots of wheels, suspension, and triple stuff but I don't see the oil lines.

[JamieDaugherty]

So are you saying you don't sell the mod any longer? Because I was all over that site and couldn't find it. Lots of wheels, suspension, and triple stuff but I don't see the oil lines.

Not any longer. I'm totally slammed with suspension, wheel swap, and other CNC machined parts work right now. I was selling these kits for zero profit, and since 1) my time has some value and 2) I'm more busy now than I can handle I had to make the tough decision. It really was difficult, I believe in the top end oiling modification and my bikes have it installed. I sold a bunch of those kits and it was the first VF part I ever offered, so it was a little sentimental too.

I've got TONS more stuff than what I list on my site. I think currently I've got over 20 items for each size/model of early VF. Some of these are just too expensive for the majority of people, so I don't bother showing them on my site.

[tinkerinWstuff]

alright. So if it isn't a "no brainer" and you no longer sell it, are you willing to offer any help for a guy who will likely have to recreate it on his own?