Few problems with VF700F interceptor 1984

Hey

I have problem with my bike.I have newly changed most of things in the motor.But I didn´t remake my gastank so in the first the was a little dirt in him but I have fuel filter on him.I had driven for maybe 30 km then the bike started with a little hickup not so you could find it just so I could see it on my rpm-meter then it got worse and worse and after 30 sek it just died then I open the seat and checked the fuel filter and it was filling up.I don´t have a fuel pump.That is one proplem the other is that when I have been riding it and the bike is warm then I switch it off and then try to start it again I can´t it is like the batteri is dead (new batteri) after I let it cool down for 2 min no problem it start up.Could it be beacause the engine is some parts new (piston,piston rings,camshaft,cylinders honed.But then it the third problem clutch and just so every one know there is diffrence between oil´s I have always used a ELF oil and yeaah I started to get clutch problem when I driving and give it gas not much the clutch slippes but then i tried CASTOR oil and the clutch is worse slippes almost every time but I can hold it on speed just not give it any gas but I think the clutch dishes are ruined just wanted to hear any other suggestion and my master cylinder doesnøt have air and he spitted fluid way up in the air when I squeesh the handle.

Best regards

Gunnar

 

Similar problem

Hi Gunnar.

I have a similar problem with my VF700F '85. It runs for 10 minutes and then quits. After a few minutes of cooling off it recovers.

I tried replacing the ignition coils, with no improvements. I am now gravitating towards the theory that the CDI units are to blame. Apparently there are two CDI units, one controlling cyl 1 &3 and another controlling 2 & 4. These are the original 24 year old units.

Since we live in the same country (Iceland) we should hook up and pool our resources. Give me a holler if you see this post : 615-0004

Regards,
---
Fubar - SRMC Road Captain
Sober Riders MC Iceland, Kerubar Crew

 

To Fubar

Hey Fubar

I will write in english so every one else can use this information.Begin at going into this website:http://users.rcn.com/kochc/moto/spark/ig_repair.html.LIke I said to you in the mail is that CDI unit 2&4 controls fuel pump and I know because I could ride my bike for 8-10 min then it died on me and if your tachometer is crazy when you try to crank the bike it is then cdi unit 1&3.The best way is to take the fuel line apart between fuel pump and carbs then switch your bike on (then the fuel pump should pump for 5 sek) then when you crank it should pump with a pulse if it doesn´t then be sure that there is fuel coming out of the tank if that is okay then take a fuel line straight from the tank ro the carbs just remember to unplug the fuel relay and go for a ride also check your fuel filter also and put a little ísvara (íslenska) in the gastank.And belive me the pressure from the tank is enough if you wanna take the hose after the body (upwards).Because if the cdi unit is damage I don´t think your bike would start or it would be really hard to start.Hope this helps

Best regards

Gunnar

 

Yeouch! Lets try to point you in good directions for each.

Yes, definitely need the fuel pump.

Sounds like residual power left in your system due to missing parts, and not enough ground. There is nothing you did new, to the engine, that would cause this.

Surely you don’t mean you put regular oil in your clutch oil master cylinder?

 

Sorry chost

I don´t have that problem any more and no I don´t need the fuel pump I am 100% sure of that because my bike runs fine now and I have found out that my clutch is bad then I mean bad (friction disc are 2,8mm or 1,098 inch the wear limit is 3,1mm or 1,2 inch). And my tank just needed a good clean it was DIRTY.When this happened there was no fuel in the filter but when I gave the tank a little rattle it started bring me fuel again.CDI unit is faulty for the fuel pump and I have one extra witch doesn´t work for the fuel pump so I going to try to fix that up and I will post it here so more can fix those (%&¤#&¤&) cdi units.For the warm part it was the radiator cap was not holding pressure and the bike overheated that is why I needed to let it cool down to restart it and I setted the valves again.And I use DOT 4 in my master cylinder.Thanks for the help anyway Chost you have help me allot in the past hope that I can return the favor sometime.And yeaah almost forgot I rode with 3 other guys witch had 85´VF700C and the other two had VF700F 83 and 84.No one had a fuel pump.But I always look out to never have to little gas in the tank.

Best regards

Gunnar

 

Made some little changes with the bike

Hey Chost and Fubar.

Finally I can set in the pictures of my bike after I have changed it.I am not finished with it yeat lot to do.

Best regards

Gunnar

 

wow, looks nice! Good Job

 

10 minute ride shutdown - solved

Hi Gunnar.

Thanks for your help m8 :thumbsup:

To be clear, the symptoms were as follows :

If I rode for a couple of minutes with the RPM above 5000, the bike would start to sputter and then it would quit. Waiting for around 5 minutes would enable me to start the bike up again and continue riding, as long as I kept the RPM under 5000. To be clear, this bike has not been ridden for a number of years.

Being an electronic tech, electrician and a s/w engineer, I of course developed a tunnel view towards this being an electrical problem. I first became convinced that the problem was the ignition coils, and so borrowed a set of Magna coils from a friend - same behaviour. Then I tried switching the CDI units - unchanged behaviour.

Solution :

After reading around the posts on VFR WORLD, and accepting advice from Gunnar via SMS, I decided to take a closer look at the fuel system.

The previous owner of the bike had installed a new fuel filter on the hose from the tank to the fuel pump. The filter was brand new and very clean. This is the main reason I fell into the trap of thinking that the problem was electrical.

I removed the fuel-pump, intending to bypass it as proposed by Gunnar and discovered to my asthonishment a second, totally clogged fuel filter underneath the fuel-pump, snapped into the original plastic holders on the fuel-pump plastic bracket. This second filter was *very* old and totally obscured from view unless removing the entire fuel-pump assembly. In order to get to this original filter, I had to loosen the coolant box under the left side cover, then remove the rectifier box (?), relays and the plastic panel beneath that, then remove the complete fuel-pump plastic bracket. Only when holding the entire fuel-pump assembly, could I see and get to the original clogged filter. What a neat hiding place for a fuel-filter!

The second, obscured filter was the culprit.

Apparently the bike was simply suffering from fuel starvation because of the clogged second fuel filter. The ignition coils (original) as well as the CDI units (original) are working quite well. The now shelved fuel-pump also seems to be in very good working condition.

The bike now runs quite happily, gravity fed - without the fuel-pump.

Regards,
---
Fubar - SRMC Road Captain
Sober Riders MC Iceland, Kerubar Crew

 

To Fubar

Hey Fubar

You are welcome and enjoy.By the way have you bought any oil kit for your camshaft.Hope to hear from you soon

Best regards

Gunnar