My Vf1000 frustrations

[techno]

Well, just to round out the topic.....

I spoke to the mechanic today and he can't cure it either. After taking up room in my garage for two years I am calling it quits and moving on.

I will pick it up on Thursday. I'll then see what the local wreckers will offer me and consider whether its worth selling it whole or parting it out.

Another old bike bites the dust... as much as I hate admitting defeat.

[Nailer45]

Originally Posted by techno

Well, just to round out the topic.....

I spoke to the mechanic today and he can't cure it either. After taking up room in my garage for two years I am calling it quits and moving on.

I will pick it up on Thursday. I'll then see what the local wreckers will offer me and consider whether its worth selling it whole or parting it out.

Another old bike bites the dust... as much as I hate admitting defeat.

Before you give up on it , try 1 more thing...take the gas tank off and remove the float assembly and the gas on off assembly..take a air hose and blow low pressure through the holes where the gas on off was and see if you can blow out any debris.. the vent on the tank could also be partially blocked causing it to cough and die...
The website www.VFRdiscussion.com has 2 members that are owners of VF1000F and more than likely could tell you what it is that keeps the VF running past 3,000rpm..Just start a thread and ask for help..

[techno]

Thanks for the advice.

I've already tried running it with fuel coming from another source other than the tank. I was trying to eliminate the tank as the source of the problem. I found out that its not. I could keep trying for years and still not get it to run right. Thats time I could spend riding.

Anyone need any parts?

[Minax]

actually yes.. I do need parts....

Fuel tank and front faring, and side fairings if you bike has them. How much, and what do you think it would cost to ship stuff to Kansas,usa? If you have pics it would help.


Actually I just had an idea.... sounds kinda simple but try reversing the firing order on the coils... even if you have the coils wired like they were when you started try them in a different order, perhaps the 85 uses a slightly different setup, try changing the coil wires from cly to cly to see if the fireing order is different. if you do have it off to begin with it would cause the backfiring and the bike would still run at low RPM and would only have problems when you reved it to about 3 grand. their verry fickel motors and timing is a big issue with 4 cams and 2 coils... perhaps you just got two wires on the same coil going to the wrong side of the engine or something simple like that.. whatever the problem.. Let me know whatever you deside. But try this first. it won't take long and it's free to test.

[chesthing]

Just curious, did the mechanic do a compression and leak down test on each cylinder?

[Ferris]

Techno - I'm sorry to hear you have reached the boiling point with the old girl...

The internet can be a tremendous resource for repair advice, but it has a limit - no one here can see / hear / touch this bike. Mechanics absorb tremendous amounts of information just through observation, without ever touching a tool. I've been repairing them for my living for 22 years now, so stories like this frustrate me. If only I could get ahold of this bike!

One thing I can iron clad tell you though - there is no such thing as an unrepairable bike. It doesn't make economic sense, sometimes (in fact, a lot of the time) but it's never impossible.

If the mechanic who looked at it can't figure it out, try another mechanic. Then you can make an informed decision.

[sparkplug0_4]

been following along and saw you said the spark weakened when you rev'ed it up. did you go through and check the pulser coil for Voltage(.1 to 3VAC) and resistance(don't know spec)? alsovoltage to your brain box(not sure the system TPI or DC-CDI) and the brains grounded to chassis. if your carbs are "good" and your coils are "good" and even if compression is a little low then it would still run, just crappy. but the fact that it "spurtters" at 3 grandish and you have tried and tested the fuel system all thats left is spark. don't give up you'll regret it trust me.

[pontiacformula99]

Sounds electrical to me... especially w/the weak spark... This has to be something over looked...

[chesthing]

After reconsidering I think it's actually low compression - the thing ran ok before he bought the used engine, hell he's tried everything else!

[masonv45]

New guy here - but been reading and messing with V-4's for about 9 years.

The only thing you changed was the engine. It's probably the engine.

Here are my suggestions . . .
- Definitely get a compression check done - as was said before, low compression could be a cause

- Sometimes when cams are re-installed, they are put back in 180 degrees out of phase. The bike will run, but it will stumble when it hits around 5-6K. I know you said your stumble is around 3K - and you have checked the timing already - but many engine rebuilders miss this.

- When running, spray WD-40 around the carb boots. If there is an air leak, the RPMS will change.

- As far as the #3 carb, after running the bike, shut it down and attach tubing to the drain nipple on the underside of the carb. Unscrew the drain screw and see if any fuel is coming out. Compare the amount to one of the other carbs - they should be approx. the same


At what throttle position does the bog down occur - 1/4, 1/2, 3/4, WO?
This will tell you what fuel circuit is being used in the carb.

[techno]

Thanks for your imput guys. I know none of you want me to give up and it probably is something simply. I have concluded that the F2 motor is incompatible with the rest of the F1. I have tried pretty much all of the suggestions in one form or another. This is also not the first mechanic who has looked at it but he has been the most thorough. Compression is OK. I have also tried swapping over the coil leads and wiring.

The other option is to rebuild the original motor using parts from the first. It's all there, just needs to be put together. It's probably beyond my capacity and I've spent two years working on it so its time to move on. Someone else might pick up the project.

Hey Minax, postage on a tank and fairings is going to be a fair hike from here. If I do part it, I'll get back to you.

Thanks everyone for your interest.

[techno]

Here's a photo of how I will remember it.......going!



Cheers

Techno

[techno]

Pic now works!

Damn my lousy computer skills.

OK, anyone else need some parts?

[Minax]

tell you what, gimmi an idea on price for all the plastic and windscreen, tank, seat, luggage rack, clutch cover, and mufflers, and what shipping would be like to Pittsburg, kansas.

[techno]

PM sent. Anyone else need some hard to find parts?

[RC26]

The 84 VF1000F has different ignition triggers and different triggering rotor these are located under the clutch cover on the right side of the crankshaft. The triggering rotor is part of the starter clutch. The triggers and rotor are matched to the spark boxes that are located under the rear fender fairing. To be sure check with a Honda dealer and see if the part numbers are different 1984 to 1985 for these items. I believe you will have to change the two ignition pick ups and the starter clutch from your 1984 motor to your 1985 motor. I fairly confident that will help if not cure your problem. However, first check the part numbers to see if they are different. You need all 1984 or all 1985 ignition parts. I would advise to leave the carbs alone (stock 1984) until you get the ignition system matched up. Good luck.

[juggernaut350]

well my bike only goes to 2k rpm like a revlimiter but its a 83 sabre 750 but it has a 700 it it i put all new (used) parts ignitor boxes (cdi i have 4 now) pulse genorators i have 3,wire harness ,carbs and still only 2k rpm it idles fine and everything it just wont go past 2k. but i will look at the starter wheel thing and see if they are the same from the 750. ahh this sux

[techno]

After giving up sometime ago, the bike has just sat in the corner of the garage doing nothing. I thought about parting it out but it seems too much like hard work selling it piece by piece. Local wrecker isn't interested in giving me much for it.

Some of my friends have project bikes in the garage and that gave me some inspiration. The other day I was away for work and dropped into a bike shop that I sometimes visit. They had a 1984 VF1000R for sale and it was the saddest looking thing I've ever seen. Not looked after at all. It made me think that mine was in much better condition for its age, if only it ran.

Its not costing me anything while its sitting there so now I'm thinking of taking out the 1985 VF2 motor (I'm resigned to the fact that its just not compatible with the rest of the bike). I'll then pull down the original motor to see what it needs doing and, if I can get it going, slot it back in. If I need any major parts such as heads, valves, pistons, I've already got them sitting there.

This is turning out to be a long term project but its just too good for its age to scrap it. Maybe I'll get some more enthusiasm soon.

[juggernaut350]

did you ever change the cdi box

[dlman]

I know that you are fed up but I haven't gotten to add anything so I am going to now. I had a dead cylinder (#2) and it wouldn't get as warm as the others. It was a blocked fuel jet. I had to take both of them out and spray out the gum from all the little holes. I did it again recently too. But the low RPMs is wierd for sure. Something tells me that the coils were going bad. They do go out you know. But if you are not in the mood to check I understand its frustrating and you have given it a hell of a try. So 3 chears to you for your effort.

[juggernaut350]

Originally Posted by RC26

The 84 VF1000F has different ignition triggers and different triggering rotor these are located under the clutch cover on the right side of the crankshaft. The triggering rotor is part of the starter clutch. The triggers and rotor are matched to the spark boxes that are located under the rear fender fairing. To be sure check with a Honda dealer and see if the part numbers are different 1984 to 1985 for these items. I believe you will have to change the two ignition pick ups and the starter clutch from your 1984 motor to your 1985 motor. I fairly confident that will help if not cure your problem. However, first check the part numbers to see if they are different. You need all 1984 or all 1985 ignition parts. I would advise to leave the carbs alone (stock 1984) until you get the ignition system matched up. Good luck.

do you think a 83 750 is diferent then a 84-85 700.i noticed that this s#%t only happens on engine swaps