VF700F Restoration

Picked up an old VF700F 1984 or 85 Not sure yet. Guy sold it to me for $300, engine sounded strong but body is in terrible shape. Haven't done much to it yet but I'm going to try and restore it as much as I can. I have read multiple forums with people whose advice is to pass it as a parts bike but I don't think this bike deserves that. Im sure itll take some time and be give me quite a challenge but with some time and effort I see it rideable or on the road in about 2 months. Im hoping to get some help along the way with this project from some of you on here. Now let's get to the condition of what I know so far.

1st this I noticed right off the bat, 2nd Gear. It doesn't seem to want to engage. I tested the bike before even doing anything to it with a new battery and oil. 1st, N, 3rd, 4th, and 5th all seem to work as they should. However 2nd gear has a slight grind and no wheel spin.

I know for a fact at the moment the clutch is not functioning completely if any at all. When i got it the master cylinder was empty and the clutch wouldn't return after being pressed. I added Dot 4 and it started to tighten up and depress very nicely but I don't think it engages completly.

Techrometer is shot and needles look like they all have fallen off and plastic was cut and reglued in their place not to mention RPM gauge not functioning at all as it bounces instead of going up as it should.

Also engine idles beautifully but after being given more gas engine dies. On startup engine will allow to be revved all the way up and wont die but won't allow it a second time as it shuts off as soon as throttle is given.

This sums up all the issues I have encountered as of now.

I'm thinking Carb cleaning for gas issue, and replacing clutch and/or master cylinder.

As for second gear this is where I need some help. Is this a transmission issue or something else?

Ill check the cams as soon as I can, currently away on vacation but will be back at work on it very soon.

Ill have pictures very shortly soon as I get to work on it.

 

Welcome WOLF! Do you have other bikes, project or running?

 

Welcome Wolf

Motorcycle gearboxes shift gear by sliding a gear sideways so it can interlock with it's neighbour, what connects the two are dogs (posts that stick out of the side of the gear) and matching slots in the side of the neighbouring gear. The gears are slid sideways by shift forks which are slim blades that reach in between the gears, and are shifted sideways by slots in the shift drum. From the sounds of your gearbox, my guess is that the shift forks are all fine and the gear teeth are all OK, but maybe the second gear has had the gear dogs broken off? Second gear usually gets the worst pounding in a hard takeoff as it is easier to miss the 1st-2nd shift and not fully engage the dogs/slots before applying power.

The attached pictures are of my Suzuki RF900 gearbox, but show the general view of dogs, shift fork and slots. In this case the bike was skipping out of 2nd under power, causing the dogs to round off and damage the slots, and flexing the shift fork at the same time (you can see the gouging).



If 2nd gear is damaged, you will need to remove the engine, split the cases and replace the broken part(s).

 

Hi, no, I do not own another bike, my brother owns a Suzuki GS 250 and really persuaded me into bikes. I was a car guy mostly. I always liked bikes but never actually picked one up. I had a car which I worked on until finally time and lack of parts killed it, and made me have to sell it so now with time and some money i'm looking forward to making this project run. I spotted it for sale and thought it was a good price for a full bike that runs, albeit not that nicely, yet. I was looking for a project anyways, buying new bike just doesn't have the satisfaction to me then one I spend time and work on to get it running how I like it. Ive read a few articles about these VFRs and VF Interceptors and became to like them more and more. Then a chance came along and I picked one up. I'm not knew to riding bikes just never owned one of my own. I expect this one to give me lots of trouble, but hopefully i'll be able to giver her some extra years to live.

 

I figured i'd have to crack it open. Just wanted some insight on what to look for. Thanks for the photos, this is just what I needed to hear.

 

Okay so today I finally put back on my carbs. Those things were a pain to put back but I found a trick to mine. I had the front two boots on the carbs and the rear boots just resting on the engine at an angle. Once the front two went in it was easy for the rear to go in with a little light help from a flat head screwdriver. Took me about 2 minutes to get them correctly seated like this.

Now I have a question, my carbs are back on and I attempted to test start it, I couldn't get the bike to fire up all the way, but if I prime the carbs it fires right up. I hear the fuel pump on startup but as soon as I go to turn it over it sputters a little but never completely fires up. Should I let the pump sit a little and fill the carbs up? Or do I have something else wrong?

 

The fuel pump should run for a few seconds when you first turn the key on. After that I it is set to run in time with the ignition system.

You might want to cycle the kill switch on/off a number of times to fully prime the carbs before starting the engine.

There is a specific flow for the pump (660ml per minute) so that you can verify that it is feeding at least the right volume to the carbs. You can disconnect the fuel pump relay harness, and jumper the white and black wires (20-6 in the service manual) to manually operate the pump.

You can also check that the carbs are correctly filling and even, by draining each floatbowl and measuring what comes out.

 

Okay so I discovered the previous owner was a wiring wizard so he managed to get it to where he doesn't need the fuel pump relay. It is completely gone, in its place was some scotch tape and what looks like one of those wire terminal fork ends. I'm not sure this is working as my pump seems to run whenever it feels like it and not when I need it to. As soon as I turn the key the pump starts to click about every 3 seconds, but it never really speeds up much when gas is given.

Also I discovered that he had wired the fans for the radiators to work by a switch, but the ends were completely worn off and the fans wouldn't spin at all. I decided to temporarily wire them up so they always spin.

The fuel pump in the bike is a Mitsubishi pump and i'm not sure its working properly at the moment, I will get a fuel pump relay and see if it sorts that out.

In the mean time I noticed my carb boots are worn and are leaking, I did the RPM test and all but one boot failed the test. So I will be looking for replacements.

As of right now my symptoms are as followed,
1. Bike has difficulty starting.
2. Only idles if left alone about half choke and more.
3. Dies if gas is given after idling.

 

I am looking for parts for my transmission and I know this bike is 1985, does the 1984 VF700F transmission parts work with the 1985 model too or are the transmissions different.

 

You need to run a compression test on that engine and inspect the cams for wear or damage before getting too excited about riding that bike. Also seems that second gear needs replacement.....OUCH !! :livid:

 

The fuel pump is really a solenoid. There is a spring that does the pumping. Once the spring bottoms out a contact on top of the pump closes and the solenoid pulls the diaphragm back. Once all of the way retracted, the contact opens and the spring begins pushing fuel again. The rate that fuel leaves the pump determines how quickly this happens, it should be about once every other second at idle. You can remove the black cap on pump to observe this.

 

R-U-Sure?

You may be better off using this bike for parts, and getting another one with a better engine trans.. You'll end up hating these V-4's instead of loving them, if you have to split the cases to even get to go for a ride! For the time it takes to fix this up, yourself, you could get a job, earn some cash, and buy a runner. You'll still probably have to mess with the "runner" but start with more appropriate tasks, such as adjusting the chain, changing oil, maybe checking and adjusting the valves. To have to tear an engine down and split the cases is a lot of work and expense. At the very least, take squirellman's advice. He knows his stuff!

 

The V4 is a tricky bike to learn to wrench on but if you can get the carbs off the bike it's really not that bad. Your biggest problem is going to be EXPENSIVE parts. I'm $1500 into mine and it's just a running engine in the chassis.

 

Well yeah I'm sure it'll be a challenge but it can't be any harder than removing and splitting open an auto trans on a car. So far this has been a piece of cake compared to that. And the carbs did make me rethink restoring this bike but I got the hang of them. Already successfully removed them and was able to work on them and put them back in in about 25-30 mins. I'm gonna check the cams and see if it's worth it but if they look okay I'm gonna continue, I've got a guy offering me a complete set of used transmission parts for less than $50. Right now I need to get it running stable. I'm thinking my pump isn't working correctly and the carbs are not getting the gas they need. My pump just clicks it does not seem to run right. I'm gonna double check the wiring and if nothing is wrong I'm gonna bypass it to test the carbs and later get a new pump.

 

I've been looking for a fuel pump relay but It's hard to find. I did find some cbr fuel pump relays that seen to have the same connecter. Would this work or is it different.