Throttle linkage and LRP ZR.32 idle problems


New Member
New Market, MD
Curious if any of the members can help me. I have a 10 year old XSS. Recently just picked up an LRP ZR.32 to replace my original K4.6 (cracked piston). I'm having a hard time getting the LRP to idle correctly. Couple things I've noticed First the throttle linkage. Never noticed this with the K4.6 and not sure if the LRP has a more narrow throttle body. However, the resting position of the throttle linkage is different depending on whether I'm giving it gas or brake. In other words, If I'm giving the truck acceleration and release the throttle goes back to ,let's say, 15% open. If I give the truck braking and release the throttle goes back to, let's say 5%.

The return spring seems tight, but it almost seems too small for this throttle body. Again, does the LRP have a more narrow TB than the old K4.6?

I remove the servo controlled throttle arm and connected a log rod to the throttle that hangs out the side so i can control it by hand. Even with that I am having a hard time keeping it idling. It will idle for 5 or so second then cut out.

Are others with the LRP ZR.32 having troubles maintaining idle?

Is there a better after market throttle rod that does a better job of getting around engine guard? My current throttle rod has the bend around the frame. I suspect that friction is contributing to this variance in the resting throttle return position.

I appreciate any suggestions that you all might have.



Well-Known Member
Dekalb, IL 60115
Got a photo of your setup? I have an LRP30 in my X, but I don't have the HPI throttle linkage, I made my own with springs/collars as I don't care for the stock split servo horn.


Savage Owner
Kenner, Louisiana
First make sure youre linkage esp rod to carb is straight with no binding. Then adjust your throttle servo return point. Turn the trim towards brake until its at full idle stop in neutral. You may have to recenter the servo arm to allow adjudtment without throwing the brakes off.

Once you have that straight lean the lsn a bit. You should hear the idle increase.