Vf1000f '84 - Starter not spinning when hot and other issue

In the Shed
1

Hello to all, I’ve finished the engine rebuild and the bike works pretty fine…
I still have some minor issues:

  1. The fuel cap is leaking and I can’t find a new spare part… I’ve bought an used VF500 one but the gasket is hard as stone, and it leaks as well… Do You know any aftermarket cap that could fit the VF1000(even without key)?
  2. The starter works fine when cold, but when hot it can’t start the engine (behaves like a low battery)…wait for 10 minutes and then it goes. Could it be an overheating of the starter improving the inner electric resistance? anyone had similar problems?

many thanks in advance

2

Hi!! both my vf’s start when hot, but don’t have the same starting power as when cold, as you say, like a low battery and starter holding back a bit, i don’t know how other’s have it.

3

I think I will check again the brushes in the starter, but if I would be able it could be a good thing to build an heat shield…
It would be hidden by the lower fairing… I’ll try with a thin alluminium one… mounted using the two bolts of the starter…
The fact that the worst starting is after sitting a while when hot, makes me think that the front exhaust pipes send too much heat to the starter
If it was a battery problem It should get worse day by day… but when cooled down all works fine…

4

Hi mako. The lazy when hot starters are an issue with the vf1000’s too… most people either rebuild them or go for the vf750 caltric starter… sadly these won’t fit on the 500. I don’t know if there are any more modern starters that will fit the 500… I have always thought that it was the heat that penetrates through the crank cases that was the problem. You can get aluminium inlulation tape from builders merchants that reflects heat… I use it on the underside of the petrol tank and belly pan… may be you could wrap the starter in this

5

The starter motor, i’d use a rebuild kit on and resolder the connections if they look at all dodgy.

Can you get the fuelcap rubber out, and measure it’s thickness?
If so you can get Viton Sheet on ebay, and cut your own rubber seal out of that.

Alternatively, if you’re using a VF500 cap, VF400 ones also fit and are available on Ebay

Hope this gives you some options,
C.

6

many thanks!
For the starter, while I was rebuilding the eingine i’ve checked brushes and connections… and cleaned… I’ll try a spare starter from another vf1000 … if it will not work I’ll try to protect from overheating…

For the fuel cap… I forgot the 400!!! thanks… I’ll try a 400 one for my big sister :wink:

7

The caltric starter is one of the best options,these are 4 brush motors and have more power than the standard 2 brush 1000 motor.
As the temperature of the motor rises so does the resistance in the windings,this will mostly be conducted heat from being bolted to the engine and very little can be done about that.
regards Bif