Well I have just installled a HSR 42mm carb on my DS, no problems with the install but i have some questions on the jetting

Currently the carb is set up as follows. 155 main, 22.5 pilot, 50 for the accelerator pump.

Engine set up K&N in air box, Custom X series 2 pipe.

Riding at sea level, temp approx 30 deg celcius.

When i first took the bike out it was very boggy at all engine speeds so I removed the air box lid and the performance improved out of sight however it still feels a bit boggy in the top end.

Any information you guys can put this way will be much appreciated.

BTW the accel pump operates at 1/2 to 3/4 throttle and yes the spring is hard on ya thumb.


regards


X-ray

 

You need to open up the air box to get the most out of the pipe and carb.

Your jetting sounds close. I assume you have the "standard" #97 needle?

You should start with the pilot circuit and accelerator pump stroke and start/stop settings. Try 25-30 for the pilot, no bigger. The accelerator pump probably would work better if the start was set as early as possible without stalling the motor. The stop probably shouldn't be past 1/4 to 1/2 throttle. When you have excellent response off the line with no bog and massive pull/wheeling then proceed to the needle position setting. The needle position setting can have a dramatic effect on acceleration - more than the other adjustments. Go up and down on the needle and see how crisp the acceleration is, such as in a drag race with good traction. Without any accelerator pump, you'd probably have to have the needle RAISED almost all the way - rich setting. Next adjust the main jet if still needed (your pilot changes will affect your main circuit). You might need to go up to 160 or 165 on the main. I found that this carb will darken your plugs noticably even when dialed in. If not your too lean.

 

I am also tyring to dial mine in..
If I just rev the engine it bogs and will kill if I dont release it. If I roll the throtle it works fine...
WHen I ride it NOT on the trail jet just around the house it bogs when I hit the gas and does not pick up after it bogs..

Needle 2nd from top
Main 142.5
Pilot 42.5
ACl Jet 50
Pump start 5mm
Pump stop about 2/3
AirFule/ Unknwoen.

Thats my setup..

 

the accel nozzle is a little large on these, that is were your bog is probable coming from. try what scooby says and if you are in a hurry to see how it works without the loading up. turn the accel pump stop screw all the way in (this disables the pump) and give it a try.

 

XRAY, I am not trying to steal your thunder here, I too am having problems with jetting..

Are my settings close??

I have extra jets
Piolots 37.5, 35, 40, 45
Main 150, 147.5,145

I will lower the engagemet and stop it by 1/4 throtle of the acl pump...

 

Correction to my post:

"Without any accelerator pump, you'd probably have to have the needle lowered almost all the way."

Should have said:

Without any accelerator pump, you'd probably have to have the needle RAISED almost all the way - rich setting.

You can temporarily stop the pump stroke to determine if the midrange is rich or lean.

 

I just installed mine but have not took it out yet. Eleiot at RW said with the exhaust and cdi the carb came set up for that has a 142.5 main and 42.5 pilot #97 needdel on 2nd clip worked best on the dyno. He telling the truth???????

 

Thats a yucky setup.. Mine came like that and it sucked.

Here is my setup
150 main
97 needle in 3rd clip
Pilot 35 2 turns out.. ( really minor jet just get it close)
Pump is a 50
Pump stop is 2/3rds stroke
Pump start is like 2-3 mm
I ran this and it runs good and pulls hard!
I run an open airbox with K&N