Great timing I am installing a hsr42 in the next couple of weeks along with a bunch of other stuff. This will DEFINATLEY make it easier, along with keeping the level in the scotch bottle up and saving my liver

I am from the days of, Map... we don't need no stinkin map


COOT

You said it coot I just got mine in the mail yesterday so the fun is just about to start. I am going to put it on the old BlackIce that I am rebuilding.

This is why I bought the roadie, no computer, carb, pushrods, belt drive and a good ammount of aftermarket stuff available with little "dealer only" bullshit.

Feel like a kid in the candy store when boxes start arriving

Ruprect wrote:
Just a quick update for everyone - Bike is still running great ! I finally got a chance to set up the pilot mixture properly. I wound up about 1-1/8 turns out. Now it warms up better and doesn't backfire on decel. While I had the air filter off (to get at the pms) I re-aimed the accel pump nozzle so it squirts just past the needle.

I haven't had a chance to dyno it yet but I'm sure I'm pretty close on all settings. No backfire on decel or when I blip the throttle & pulls hard and smooth all the way to redline. Haven't ridden far enough yet to check cruising mileage. I'll be making a dyno appointment soon to check the AFR's.

On to the next project now ! I want to lower my hard bags 3". I'm making myself a set of lowering brackets similar to Geno's but the fender brackets will mount inside the fender so as not to be visible. I'll also be slightly re-working the braces on the saddlebag mounts so I can move everything in closer to the fender without the swingarm hitting them.

Pilot screw adjustment really needs to be done on a warm engine, and with air filter on. You're probably still close, with-in a half turn. fortunately since this controls the mix of air and the pilot jet controls the fuel flow, it plays less of a role in mpg's. unlike the stock carb where the pilot screw adjusts the fuel flow. Pilot ckt kind of has 2 ckts, idle and just off idle to 1/4 throttle and diminishes as throttle is applied and more fuel comes from main jet

Bike was warm when I set it up. I have the billet backplate and it was going to be difficult to accurately adjust with the filter/backplate on. I also have the HUGE Speedstar competition air filter on and I figure it probably has almost no restriction effect at idle so I'm not too worried.

A BIG thanks to everyone on the forum who blazed the trail ahead of me as far as the HSR42 is concerned. If I'd had to figure all this stuff out on my own I'd have given up long ago !

Regards,

Rup

Well I tore into the 42 today. All I can say is some people shouldn't work on their bikes! The guy over torqued everything on it. The throttle cable idler wheel was broken and the #2 accelerator screw had half an ear broken off it. The main jet has a big burr on it from over torquing it and the choke cable was bent with a broken back nut and it looks like the oem cable off a OEM 40mm carb. He had a 170 main in it and had the needle set on 3. The smallest main I had was a 165 so I put it in and set the needle back to 3. Put the buffing wheel to the bottom back of the bowel just to see and boy it polished up real quick. At some point I may tear it down and polish it put a rebuild kit in it. I did order the idler wheel and the accel screw. I think some people work on stuff with just a hammer screwdiver and pair of pliers.GEEEEZ I had an old carb off an early model R* so I pulled the TPS off of it and am ready to do the mod soon. Everthing was stock in it except the main jet so I may have to get the tune kit for it. I'll wait and see when I get it on. I do want to get the Yost power tube. BTW all years TPS are the same part number if anyone wants to know. Glad I had a spare that way I can always go back to the stock carb and keep the 42 for the other bike if I want.

Any one running the Yost Power Tube with the HD jets? I am having trouble finding the Yost that runs the Mikuni jets. To me I don't see that it matters if you get the jetting right. Anybody know what the diference is between the HD and Mikuni is?

the thread are different on the main jets, but size numbers will be the same. You can go right to his site and get this product:

MHSR-M - Kit uses Mikuni Jets that are not included.

I had to look around his site to find it, was on this page:

http://yostperformance.com/products/motorcycles_cv40.php#pmb

Yes I know the Mikuni threads are smaller than the HD but if the orfice size is the same wouldn't the HD set up work just fine?

Bob Yost makes 2 power tubes that fit the 42hsr, one uses the mikuni round head main jets, which have a finer thread. the other tube uses the Mikuni hex head main jets which have a course thread. for whatever reason the tube he sells for the round head jets only comes with the power tube, the the tube he sells for the hex head comes with power tube and some CV style jets

It will work fine, since they are still Mikuni jets, they are still numbered the same, a 170 mikuni round jet still flows the same amount of fuel as a 170 CV jet