Harley Davidson Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
104 Posts
Discussion Starter #1
Hi
Have anybody tried to Mount MIKUNI HS40 to 1200 Sporster? I’m trying now but it dont work at idle.
Does anybody know what jets (main and pilot) work best?
I have 1987 sportster 1220 (883 conv.) and I’m interested in something between economic riding and horsepower.
 

·
Rider
Joined
·
1,541 Posts
What do you mean it doesn't work at idle? Does the bike start/run but it won't stay at idle? Do you have to constantly mess with the throttle to keep it running?
 

·
Retired citizen
Joined
·
23,458 Posts
Try adjusting the idle air screw, not the throttle cable idle screw.
Jetting instructions come with the new carb. I'm assuming it's a new carb.
Make sure the enrichener cable isn't binding up.
Any change with the enrichener on or off ?
 

·
Rider
Joined
·
1,541 Posts
It sounds like the carb is sucking air somewhere where its not supposed to. check for intake air leaks or cracks/gaps in the seals.
 

·
Wayward Son
Joined
·
23,351 Posts
FWIW. Since you have not said if it`t a new or used carb, I`ll guess it is used.
Follow the suggestions already given.
In case you do`t have a manual. Here is a direct d\l for the HS40. Totally legit and legal right from the Mikuni site.
pdf format.
http://www.mikuni.com/pdf/hs40_manual.pdf

You can view it by clicking on it or download by right clicking and doing a save as.
 

·
Wayward Son
Joined
·
23,351 Posts
Beat me to it TS I just remembered Mikuni has a good web site.
:thumb Mikuni America is a pretty class act. Good product.
Ran a 40 on my old 80" Shovel. A 42 on my 98 FLH.

For anyone interested and does`t already have it bookmarked. Mikuni American Corporation

Changing up on T~S. Going with a massaged CV on it.
 

·
Registered
Joined
·
104 Posts
Discussion Starter #10
Ive tried adjust it - nothing.
My sporty 1200 dont want work with this carb. Dont have low idle. Only up 2000RPM. When im trying make a 1000RPM - engine stops.
On my EVO 1340 works good - on sportster doesnt.
 

·
South GA Redneck
Joined
·
3,898 Posts
I have a HSR on my 1200 sporty and have no issues with it. Don't know what's going on with yours. Don't really have anything other to add than what's already been said. I hope you can figure out what's going on with it.
 
1 - 11 of 11 Posts
Top