OK FOR AN OKO ?

OK FOR AN OKO ?


OK FOR AN OKO

Having bought one, read all the rave reviews, the time has come to give it a go. First I have to say the
Mikuni VM26 that I’m currently using works like a charm so if this “new boy” is better then I will be
impressed big time !

The kit came from Mid Atlantic Trials with extra jets and a guarantee so they think its the Bees Knees
on just about all the bikes they have tried it on. With all the engine mods done on mine I had to come
up on the pilot  using the Mikuni so may have to go the same route with this fella, and of course I’m at
7000′ so my final jetting will be different from anything people are using down at sea level.

Lets have a look at the beast in some detail and see whats what. First thing to note is the float bowl
is only secured by two bolts instead of the conventional four. On the air intake side it takes a 2″ filter
body and they recommend my favorite podded UNI system which I have used for many years. The
airscrew Is an airscrew and not a fuel screw and the final position needs to be between 1 and 2 turns
out when it is set correctly. You can buy a see through plastic float bowl as an extra.

Rough castings and only 2 screws holding the bowl on

Chromed flat slide, top cable adjuster would not fit my cable

Taking it to bits it is much cruder than a Mikuni as the casting in many places is rough and looks like
it needs finishing. Internally the “flatslide” is flat on the air side and semi curved on the engine side and finished in chrome. The Cable mechanism I quite liked with a plastic locking unit to secure the nipple
in place that is connected to a very strong spring. In order to fit it was necessary to give a little more
free cable so the Domino had to be undone. My cable would not fit in the OKO cable adjuster so I
swapped the Mikuni adjuster over.

The jetting that mine came with was 115 Main, Needle on 2nd clip from top out of 5 and a 48 Pilot with
airscrew at the 1.5 out setting. It also came with a spare 45 Pilot and 112 and 110 Mains. All breathing
through the UNI podded filter. Worth noting here that during the SG rebuild I used a “stack” type hi-tech
filter but this proved to be worthless as it let a lot of dirt through….. so stick with UNI or K&N in my
opinion.

Fitted and mated up to the big angled UNI

It fired up on the second kick and after warming the tweaking began. Increase idle, and now adjust
the airscrew for that increase in revs and the treasured sweet spot. Seems I was bang on with those settings !! and the afternoon temps were around 90F up here at 7000′.

Out for a little testing and it pulled cleanly all the way off idle, (and I always set mine with zero tickover
and a smidge of free play in the cable), right through the range in first and second. To be honest I
can’t say if there was any discernable difference between the two carbs but I’ll be looking at some
further testing in the coming weeks.

Running with zero tickover and no clutch 

Smooth pickup from tight turns

Instant wheelie

I have certainly enjoyed riding SG in the first 3 events of the season and my return from the enforced

sabatical, however, I still love riding that Cub so I have plenty of choice for the next bunch of trials only
a month away.TONY DOWN

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Comments
  • 7/21/2012 1:49 PM Chris wrote:
    You would have found that a 28mm OKO would have worked better than the 26mm (?) that it looks like you have.On your bike a 28mm OKO working in conjunction with a large volume air box, bit of a clean up of the ports, and .6mm squish clearance, would really make a big difference and might be worth looking at some time?
    Reply to this
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