Attempted VF1000F2 resurrection

https://forum.vf1000.com/t/f2-keihin-vd85-e-main-jet-size/2189/3

 

Yep I found that too, so I wonder who shoved such massive jets in here

The PO would not have done that, too much of a bodger, they are the right carbs for the bike I’m sure VD85E

I will have to see what’s in the F carbs and if the F are in better condition they may just get cleaned and swapped


VF1000F2F, in bits

 

At some point, somebody probably had some 1984 carbs too and combined parts. I'm still trying to figure out why the 1984 has such massive jets. I read somewhere recently (I couldn't find it again) that the 1984 carbs are vented slightly differently with air box and/or crankcase pressure and it changes the jetting needs. I don't remember seeing anything different than my 1000Rs, but it has been a long time since I've been into my 1000F.

 

I see there are some cheap jets on eBay

I could order some 115 and 120 as they don’t have 118

It’s only a few quid and a couple of hours work


VF1000F2F, in bits

 

"The 82’s will probably be fitted with 145 and 150 main jets, and will have different slides and will vent into the plenum chamber.
The 82’s will fit on your bike as a full unit and work ok, you cant change bits from one carb to another, you will lose the vent to atmosphere which on paper gave the later models a few extra horses at higher revs."

 

"Just to confuse things more, some of the early 82 and 83 carbs were fitted with a “carb revision kit” designed by Honda to vent them to the atmosphere, these had smaller main jets 115 or 120, and the newer teflon coated slides,
I actually have a set of these on my boldor which runs ok."

 

I’m sure the parts bike is an SC15

Think we checked the engine number to an F
Other than that I have no idea what it is, got a silver and blue tank, which is full of black sticky stuff, that used to be petrol


VF1000F2F, in bits

 

If the emulsion tubes are the same front and rear, I would personally try 120 in all 4. And have some 115 as a backup plan.

 

If you look back at the pictures
There are 3 of one type of emulsion tube and 1 of another

The odd one has holes right at the thread end, the rest have the holes much further up

Is this going to have an effect I wonder


VF1000F2F, in bits

 

Somebody has done a terrible mix and match job then. I've only seen and read about all 4 emulsion tubes the same or front and rear sets matching. You need to get those other carbs and take some stock first.

 

I am sure I read somewhere that the tubes with the low holes go either front or back and the opposite high holes, something to do with the angle of the carbs

Found this thread that explains the different tubes

https://vfrworld.com/threads/carburetor-main-jet-holders-diaphragm-springs.25321/

So I now need a tube for the rear pair

VF1000F2F, in bits

 

It’s also due to the rear carbs run hotter and so require extra fuel to cool. Everything I read suggests that the mains are on the low side anyway so putting in 120 all round looks to be sensible

 

Low?
Fronts are 162, rears are 158

120 is much smaller


VF1000F2F, in bits

 

There is no way those jets came from Honda fitted

 

I agree

The manual says 115/118


VF1000F2F, in bits

 

145 / 150 size main jets are only for the 1984 VF1000F (vented to the plenum). Your 158 / 162 are likely from some 1984 carbs that were jetted for some kind of exhaust system fitted and a modified air box. All the other 1000 carbs are going to be in the 115 to 125 range stock (some reports of 110).

 

I should get the carbs off the other bike tomorrow

Been out in it again today, with out the fuel pump jumped, and below 5500 it’s superb, the hill issue has gone, must have been the jumped pump

And over 5500 it’s like it’s suddenly gone on choke, so we are defo on the right track with these jets, I wonder if it was done for the Laser Cans

If so they broke it


VF1000F2F, in bits

 

Get together at least matching emulsion tubes, or 2 sets that meet the criteria of that info you found regarding holes. Then get your self some 120 mains if the other set doesn't have something close. Your F2 carbs are way over-jetted. One of my 1000R with full 4-1 exhaust and modified airbox only takes 135.

 

Found a tube on eBay £5

Be here sat, do you know a good source of jets, the ones on eBay seem to be massive sets 80 - 160 don’t want to buy used or 4 sets


VF1000F2F, in bits

 

I have been able to find individual Keihin (or replica) jets on Ebay for my projects here in the U.S. and the pricing can be decent.

Here is an example:

https://www.ebay.com/itm/Keihin-Gen...=39290830198199d406ac291644d08c9aad7757d8aa71