Dynojetting BolDor carbs

I’m in the process of cleaning and fitting a a dynojet kit to a set of carbs destined for my modified Bol engine.
The instructions direct you to use the jets in the kit nearest to the standard main jet and should be no more than six points away from it.
The smallest jets supplied are 122 the Bol uses 110s
Do any of you guys have experience with these kits?
The plan is to keep the present carbs standard as a backup in case there are any problems.
Once completed I intend to have the bike Dynoed over in Malton,the garage there has a good track record with the big VF.
Any pointers would be appreciated,regards Bif

I’ve installed a DynoJet Kit #1121 (Stage 1) (1984VF1000Fe).
The bike was using a lot of fuel and would not idle at 12,100’ (a high pass in Colorado).
Fuel consumption dropped a lot after the kit.

But not sure if it was a waste of time.
The instructions got me to get the Idle Mixtures just right (was WAY too Rich).
Drilling out the slide lift holes added to Snappy throttle response.
The new Needles have a complex curve to them, so I guess you gotta use their Main Jet.
Their Springs were all the same length (unlike Honda Stock).
Rember that the Main Jet Size only makes a difference at WFO, so no biggie there if you’re off.

Speaking of Main Jet sizes,…

What the Hell!?!!?
Where’s the truth?
I removed my Honda #145 & #150 and used Dynojet #136.
Does that mean I went straight across?

I think the best thing the kit got me to do was set the Idle Jets properly and Sync the Carbs.
Probably could saved a bunch of money & effort if I did that first.

Got another issue with the kit.
I currently have a stutter/flat spot at 3200RPM.
Don’t know if its Rich or Lean there.
I suspect Lean (stock Air Box).

I figure the Dynojet Springs are too strong and the Slides are not yet lifting.
I may put the Honda Springs back in, see if it goes away, since the caps can be removed without removing carbs.

Hi bif

When I fitted kit to my FE with RF engine but FE carbs k&n filter and 4 into 1 and standard air box used 150 main jets which made it a bit rich at full throttle but good response lower down. Have now fitted to RE with k&n filter 4 into 1 and standard air box with 122 mains and it feels better than on the FE though did not drill slide lift holes on either but will do this before Scotland trip! Should have read instructions fully, I thought drill was for air screw which is not needed on uk model as it is already accessible. When I drill slides will look at needle clip position and let you know.


Thank you both for your input,I will set up as per the instructions using the 122 jets and fitting a KN filter.
I will let the boys at Dynobike in Malton do the fine tuning.
Best regards Bif

Couldn’t remember drilling out holes in slides but when I looked at drill it had been used ( it was a long time ago ) so I removed slide from rear cylinder and found it had been drilled out so I must have swapped slides from FE when I swapped spring and needles, anyhow I checked needle clip position and it is second groove down. Biff are all the slides the same for the different models and if not what is the difference? I’m happy with how the carburation feels on the RE but the FE feels very sluggish though it still has the 150 jets in so is going to be very rich with standard filter and needles.


FE and RE use the same slide,FF,F2F,RF and RG use a different one.
The only difference I can see is the slide hole diameter,remember the early models carbs vent into the air box and FF on vent to atmosphere.The revision kit has later model slides,blanking plugs for the air box and linked air pipes that vent outside the air box.
It also contains a set of 110 main jets.
The factory notes on the kit suggest problems with lean running at high revs and problems with hot starting could be rectified by fitting this.
Regards Bif