Hi Don,

First, here's a link to the HSR tuning manual; it's written really well with lots of tuning tips:

http://www.mikuni.com/pdf/hsr_tuningmanual_021003.pdf#search='mikuni%20hsr%20manual'

My final carb settings are:
155M
20P
96 Needle 3rd clip position
Acc Pump nozzle 60 (leaner)
Pilot Air ~2.5 turns out (tune per manual)
Acc pump screw #2 set with 4 threads showing

However, I'm running a Yost power tube and I believe your 160M is OK; maybe drop to a 157.5 for fine tuning. I also think your intake breathes better than mine which might call for more fuel.

My 20P is a little on the lean side according to my EGA, but I like it like that; it's crisp off the bottom. Your 25P should not be far off.

The manual has the part# for the 96 needle, which is richer and I do think you'll need it.

Your stock Acc Pump nozzle is probably OK too, but after you sort things out and if you encounter warm engine coughs off throttle, the smaller nozzle will help.


BUT, what you're describing doesn't sound like jetting problems. The stock Harley jetting has worked on many R*s; it's just not ideal.

My best guess based on the symptoms you're describing off throttle is an intake leak.

The HSR is shorter in depth than the stock CV. Some intake/air cleaner kits don't tolerate that difference very well and make it hard to seat the backside carb mouth into the intake manifold. It's hard to see without removing the tank.

Even on my "forgiving" bracket mount Thunder S&S, it took some time to get everything snug. On an intakeair cleaner kit with a hard mount plate, it will be tougher. Check this carefully.

Watch out for a condition where the air cleaner mounting tries to pull the backside carb mouth out of the intake manifold. There's not much room for error and it doesn't take much to create a leak.

You didn't mention if you replaced the petcock. If you're running stock, you may be starving for fuel on the top end, but that would not explain the off-throttle problem. If after you sort out the off throttle problem, you're still flat on top, consider a high flow petcock (Pingel), if you don't have one already.

And, make sure the choke, if hard mounted, isn't so tight that it's never shut off.

Hope this helps

Jim<br><br>Post edited by: Bucardo, at: 2005/03/12 21:50

Jim
Thank,s for the takeing time to do this. I well go back and check all my
intake and make sure there is no leaks, I have look but I well do this again.
Been look for a high flow petcock,I,ll go and find one know I have a name.
If I don,t have know leaks well try the jetting. and go from there.
again Thank,s for takeing the time.
Don