The 15 degree jig is encouraged by the manual because it tries to eliminate any compression of the tiny spring loaded shock absorbing "tit" on the float needle when the actual float tab touches it. You can hold the carb at a certain angle to get the float to pivot and rest on the float needle with the needle seated but no compression to the spring loaded "tit".

Hard to describe how to hold it, but the goal is to have the float needle seated, and the tab on the float just touching the tiny spring loaded shock absorber "tit" WITHOUT compressing it.

As mentioned, usually having the float "parallel" with the float bowl body and no compression, is a good guide if no means of measuring. I agree, the fluid level tube is a great way to confirm, but bike needs to be sitting up in the riding position. YD

 

Exactly

 

G'day Fellas.
Thank you all for your input.
Yesterday I pulled the 99C apart. This is the one I'll use. I set the float height (as per instructions) and ended up with 13.5mm height to bring the fuel height to level with the joint surface (carb sitting horizontal). It now has a 45 slow jet but still a 190 main, the next size down I have is a 175 so will order 180 & 185. Everything looks good, all passages are spotless.
Now for the bummer. Both carbs are missing the starter (enricher) valve so it's all come to a screeching halt till I find one and make a cable to go to the choke **** in the dash panel. I'd also like to utilize the "cruise control" if anyone can point me in the right direction. Last question. On the 99 there's two tapped holes at the butterfly shaft below the starter valve. Is this for a throttle position sensor? Not that I'd need one,flat out or stopped are my two preferred positions LOL.
Cheers

 

I don't remember you mentioning your cam but may have overlooked it. If it's stock or very mild, a 175 will work but having the 2 extras you mentioned is a good idea.

You can buy the entire (aftermarket) cable/enricher assembly, though I don't know about shipping or availability down there. Even the HD cables seem cheap but they work. I never used the others and hear they work OK but the cables portion is really junk.

Otherwise you need:

27583-88 Starter Valve
27315-88 Spring
27581-88 Starter Cap
27580-88 Cable Guide
27582-88 Cable Sealing Cap
29236-90 Cable, enrichment

The actual cable part will only be long enough to reach the left side under the tank, so making the choke work with your dash mount may take some creativity.

There's been a few on here over the years who have re-installed the cruise on their newer models but I don't recall anyone retro fitting. There's a lot of electrical and special parts that will be near impossible to find and suspect it would be a "bridge too far" trying to make it work like it should.

 

That's the same thing I was thinking when it comes to hooking up cruise?? It would be a job!

 

Thanks Fellas.
so making the choke work with your dash mount may take some creativity. That's my middle name LOL.
The "cruise control" is just a cable so may use one of those old choke/advance levers off the Pommie bikes. Just finding one to fit 1" bars.
Found a cable local, asking for the other bits. Will know Monday.
Cheers

 

Do you have the thumb wheel on the throttle? That is my "cruise control" but don't really use it all that much. Just during long distance steady cruising road trips. YD

 

The cruise control system uses a cable to the throttle cam on the carb, that's true. But also uses an electrical servo, control module and a lots of wiring. It also needs an input from the generator on the speedometer (early Touring models w/cable speedo) or the speedometer sensor (on later electric speedo models) and brake light switch input. Not saying you can't, but seriously doubt it'd be worth the effort.....

To simply fashion a throttle lock other than the handlebar drag control is easily doable but dangerous. They make thumb extensions for the star wheel on the grip, they work pretty good and are inexpensive.

Here's mine. This style hard to find lately, less than $10. just push on. But they break if you try to take them off. There are others for sale these days though I've not looked lately.



-----------------------------

If you're inventive or know how we used to repair and modify cables back in the old days, by putting a ball end on you long style choke cable, I can see how you can make the dash mount choke cable work. Actually, that would be really cool and hope you'll post back with photos.

One last thing, replacing the butterfly Keihin with the CV, I recommend you replace your throttle cables with post '89 cables. Otherwise you'll have to cut approximately 3/4" off the housing of one of your cables. Easy to do but I always replaced cables on every one I did since. Been 20 years since I switched one using old cables and cannot remember whether it was the idle or pull cable that required housing modification.

 

G'day YD.
Yes that thumb wheel is there but doesn't seem to work and would be a pita to use.
G'day t150.
Yes I've seen those extensions for the thumb lock. Will be second choice if I can't make the cable system to work. I'm not shy to making cables.
Bugga, just put new cables on. Thanks for the tip, will do.
May be a while before I get back to this project. The 1951 BSA needs a full motor rebuild. Been 30 years since I did the bottom end.
Thanks for the help Fellas.
Cheers

 

You can rebuild the workings under the thumb wheel - parts still avaliable thru HD. In fact I highly recommend doing that if even considering a gadget like I posted. They do work well but ONLY if the drag shoe and spring are in decent shape.

Since you just replaced your cables, just go ahead and "trim" the housings they'll be fine. The one I trimmed had 15 year old cables - it was a rush job. Again, cant remember which one need the housing shortened, may have been both. Either way, it was very straight forward, just spread the housing coil and cut.

Have fun