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neppomuk

1984 VF500 Project Start

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Hello again,

 

some time has passed since I bought my 1984 VF500. You will find my introduction thread here:

I would like to continue in the origin thread but unfortunately it was closed.


Anyway, not much has happened since I bought it. I started the engine once and drove up and down in the driveway. Doing this I figured out that the clutch is not separating properly. It was impossible to change gears as long as the engine was running. When the engine is not running I can go through the gears clean.

 

I bleed the clutch system but it did not solve the problem. After this activity’s the bike was parked in my garage covered under a blanket for the last two years. Unluckily I had no time to start this project and also I was not sure if I will go for a full restoration or just refresh it a little bit or keeping it like it is. Anyway I knew that it is there if I need it.
Finally last weekend I decided to start the project and so I did.
The first part to strip down the bike was the easiest one, and at the moment this is the status:

8bf3da35-e0b3-44e0-a8bd-c43458625e2f.thumb.jpg.283c83ed0cd6c8fa83803855ec761ada.jpg

 

As I mentioned already in my first post two years ago the rear frame of the bike is bent a little bit, also the front fairing carrier has seen better days. Therefore my first task is to find a company which can repair (bend back) the frame. 

 

During the disassembly I found out that the exhaust (especially the left one) has some corrosion on the lower side arriving from the inside. I thought of buying a “new” used one but after a quick research I found out that this damage seems to be quite common and the ones I found on ebay seemed to be worse than mine. 
Is there a way to repair/weld the exhaust and prevent it from further corrosion? As it is double walled and the corrosion is arriving from the inside it doesn’t seem so easy to me to repair it. 

879190a3-7cc2-47e2-b7cb-55b745109d77.thumb.jpg.3dbd5b0d28da7ed0d3316994fa1519e1.jpg

 

BR

David

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best not to delude yourself or invest time or money in a VF500 unless it passes a compression test FIRST thing !

 

if yours runs with no disturbing noises, it's lucky.  you can't shift properly cuz during storage the clutch plates have stuck together.  they can be freed-up by technique without taking anything apart.  ride and use both throttle and rear brake at the same time to break the plates loose. or place front wheel against a wall and, in gear, give it some gas.

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Thx for your tip squirrelman, the problem with the clutch happened already two years ago so there was no long storage before, but I also think that the clutch is sticking together for some reason.

 

Anyway, before I start to have a look on the engine I must clarify the condition of the frame. Yesterday I had time to go on with the disassembly and finally I could pull out the engine. With the frame now separated I noticed that the right lower tube has a slight bend to the outside whereas the left one (the subframe part) is straight. Unfortunately, I did not make any picture from the front but I marked the area in the picture. I don’t know honestly if this “bend” is original or a damage, can anyone tell me?

 

Furthermore, when I connect the subframe tube on the upper part of the main frame it is dislocated on the lower side to the main frame (see also attached picture). There is not a lot of force needed to push it in the correct position, but again, I don´t know if this is normal or another indication that the frame is damaged/bended.

Please let me know how it looks on your vf´s.

 

BR

vf_frame_02.thumb.jpg.59c0a310d70552a2dac938b7c38d5cd2.jpg

Inkedvf_frame_01_LI.thumb.jpg.c2324c2b24a4917d345787a9f3219d8a.jpg

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I'll be home in an hour or so and will check the RHS frame rail on mine.

 

 

Never had the engine out so cannot judge the LHS....

 

There should be "drain holes" at the bottom of the rails; the 86 had them from factory but yours is a 84. If the previous owner didnot drill them, you could.  It freezes in Austria too in winter...

 

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Hi Dutchy,

thx for the information. I know already about the issue with the drain holes. They are already there, I remember it was one of the first things I checked two years ago 😃

 

Would be nice if you can tell me if your frame also has the bend.

I can also make some pictures in the evening to explain it a bit better.

 

br

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Alles im Grunen!!!

 

Left spar is straight

IMG_20190424_131107.thumb.jpg.503b18037ea58ecfbba8ed7b4cd1249c.jpg

 

Right spar a curvature

Holding a ruler flat to the bottom of the spar:

IMG_20190424_131022.thumb.jpg.388c9b2c8f1a1ecc1a6d5f85e3da0516.jpg

 

IMG_20190424_131008.thumb.jpg.084715e73201846bfd5c7cc84fbae520.jpg

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Today I had some time to measure the compression of the engine. 

Unluckily it did not show great results. The good news is that the compression is similar on all four cylinders. The bad news is that the values are really low (70-75 PSI).

Putting some oil into the combustion chamber did not show a significant increase of the compression rat. 

At least I have a reason now to open the engine 😁

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I honestly wouldn't bother. I bet it will still run just fine. I see from your first post it did run. If the the figures are real they are low but it's very unusual for them all to be low. 

I would query your gauge first. If the engine is that badly worn it's beyond economic repair IMO. Try to find another one.

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Did you use a compression gauge with a (too) long or (nice) short rubber hose? 

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I also did not believe the values, so after the measurement I tried to check if the gauge is giving correct values. I tried to pump in air with my air compressor and so far, it seems that the gauge itself is giving correct values. But honestly, I did not think about the rubber connection line between the cylinder and the gauge.

As the valve is placed at the gauge this could really make a big influence especially with a small combustion chamber of only 125ccm.

 

Maybe I can find a way to evaluate the gauge further.

 

Anyway, having a quick look on the valve clearance it seems like there is nearly no clearance at the outlet valve. But I still must take a closer look, as I had only a few minutes of time yesterday.

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The fact that it ran and they are all pretty much equal, pretty damn sure your readings are just low at the gauge.  Check your cam lobes and followers.  If they are good, check/adjust your valve lash, button it up, and ride the piss out of it.     If you end up having problems down the line, then source another engine.  Taking a 500 down beyond the heads is a losing proposition these days.

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Did you do the compression test with wide open throttle ? ie full throttle. 

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Yes... WFO (wide fooking open)

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Hi,

The test was done with the engine already disassembled from the frame. This means also without carburetors and so on, the intake was completely open to suck air 😉

Since all cylinders were pretty much the same, and the engine was running, I'm not worried.

In the meanwhile, I had already time to check the valve clearance, nearly all of them are too tight.

 

Anyway, I will go on and disassemble the engine further, the minimum I would like to do is to check the valves and sealings and regrind the seat of the valves.

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