2003 sportster 4tec have rpms no thrust

[rynob1020]

i just baught a 2003 sportster 4tec took it out and was running
fine went to idle then gave some throttle could only get abot 10 mph
but seemed like i could get 8000 rpm but felt a slight vibration
would gradualy pick up speed but would loose it agian
any help would be good

 

[kustomkarl]

It sounds like the wear ring is in need of replacement. The Impeller pump needs tight clearances to maintain the thrust needed to propel you forward.
Here are the specs;
Wear Ring clearance for ALL 4-tec 0.035 mm or ( .014in) Measure the clearance at the center of the impeller blades, with a 12” long guage. Measure the clearance from the venturi side of the jet pump.

If this is the problem let us know and we'll point you in the right direction to replace it. It isn't a hard job and you only need 1 special tool to do the replacement that cost about $25.00.
Keep us posted.

Karl

 

[capone2841]

thank you, just finished the gtx..