I thought I'd open up a thread on dialing in my HSR 45 carb. I'm gonna need some jetting help later on.

First off, my mods are :

2000 DS 650
RWR Full Exhaust w/ RWR Muffler
RWR CDI
RWR Ported Intake Manifold
RWR TM45 without the pump
K&N Filter in stock airbox with lid on.

K, took the carb off the machine and tried taking off the float bowl today...Yea....2 partially stripped screws, and the screws are still as tight as they were yesterday...They will not budge...I have the right size screwdriver and all...So this has halted my progress to a complete stop....grrrr

Things that I've found out :

155 Main Jet (could open drain plug tho)
I live at sealevel.

155 seems kinda big for the mods that I have compared to other guys on the forum...With sea-level elevation, is a 155 good?? What do you guys think??

Now, if I can only get those damned F*%&ING screws off and replace them with those stainless Allen screws, I'd be happy...

Thanks in advance

 

I know about those screws. I had to get some good pliers(robo grips) on the side to move the screw and then I could turn it. That jet seems big but Im no expert in the field. I suggest getting some plugs and reading them. I believe I have a 142.5 in mine on gas but I usually run alky. Ill check and get back to you.

 

Okay,
155 Mikuni Main Jet
40 Mikuni Pilot Jet.

What do you guys think of this jetting for the mods and elevation I have?? (Listed above)

Thanks Again

Jeff

 

try a 150 and a 45 pilot

 

Ok, before we tell you what to do.. What is your carb doing? Why do you feel the jetting is off??
I belive the 45 pilot is fine!!
The 155 is on for WOT.. I would go to a 152.5 if you feel your to rich at WOT. I run a 150 in my 42...
The biggest part of the TM carb is really the needle. Pull your needle and move it to the leanist. how does it run, move it to the richest, how does it run.. THen just fine the sweet spot...
Mine is 2nd from the bottom. I can only go 1 clip richer...

 

For the pilot - 40, 42.5, 45 seem to be the most common, and you want the one that leaves the idle mixture screw between 1.5 and 2.5 turns out. You turn the idle speed way down, so its almost gonna die, and then turn the idle mixture screw in til she chugs and won't run, then out til she chugs and won't run, and leave it halfway between those two points you identify. The end result should be around 2 turns out, if its less than 1.5 go bigger on pilot, if its more than 2.5 go smaller, but by all means use the largest pilot you can within these parameters because it will help with cold starts and throttle response.

Set the needle where it gives the best performance, like Mudstud said - try each clip postion and stick with the one that gives the most rapid acceleration from 1/4 to 3/4 throttle - the one that brings the front end up the easiest and fastest with the most agression. Just cruise along at 1/8 or 1/4 throttle, about 3K or 4K, then punch it to about 3/4 throttle (not full) and the groove that yanks you the hardest is the groove for you.

Main jet is the trickiest, I recommend not looking at your plugs until done, once you find the right jet based on results, feel, and sound of revs, your plug will be the right color. Just try each main until you find the one that revs that fastest from 3/4 to full throttle. You can hear it and feel it when you find it - cruise along a little over 1/2 throttle, about 4K, then hammer down wide open and the jet that gets you to peek rev the quickest is the jet for you - feel it, but listen for it too, its talking to you man, its like Zen and the art of carb tuning. More than likely, you'll find yourself dropping down around 150 from that 155. You want the jet that gives the best HP - the fastest path to peek rev for the quickest drag.

naturally, you gotta do all this testing under the same traction conditions - the same day at the same place. play with each circuit one at a time with an organized method and after a couple hours you'll really like the end result!

 

Good stuff Hightower.Im going to try some of these tips also.

 

Okay.

Mudstud : When riding at mid-high RPMs, most times, when I release the throttle, the engine will sputter and dies (seems like flooding). Also there is a big hesitation when I slam it off idle. (gonna learn to live with it, but gonna try to make it better).

Hightower : Okay, I'll print out what you said about finding the right pilot and air mixture. So I guess i'm gonna need to order some jets. I'm a cheap ***, so what size jets should I buy to try it out. I'll buy a few but not too many there...at 10$ each...eh. Also, should I order a 150 now, or wait till later??

And finally, will changing jets and needle positions affect my gas mileage considerably???

Thanks A Lot
Jeff

 

let the gas mileage thing go, it's a 650 high performance quad[img]i/expressions/face-icon-small-smile.gif[/img] they do make these racks that can carry extra fuel.

 

Hey guys this is some good stuff, i havent hooked up my 45 yet but am waiting until i get my dual setup finished and i ordered a direct mount a while back but havent got it yet, anyway my quesyion is do you think its worth it to get the accelaerator pump activated? will it remove the low end loss or just the stumble, o ya i bought a harley 45 so what exactly will i have to change? I remember i have to block off somthing and thejets are way too low. but anyhelp would be appreciated. I cant wait to finish my bike up its been too long since i last rode it. thanks for the help guys.

Here are my mods
Dual exhaust Custom
hsr45
direct mount k&n
milled intake
rwr CDI

and i think thats it any help would be appreciated