I have a 1998 Road King and a Motorvation Spyder HD attached. I have the carb off and was thinking about rejeting it for the extra weight now that the sidecar is on. Right after I bought it new I did rejet(for the Harley folks-a 185 main with a 45 slow using the stock needle)and that is how I have run it for most of its life as a two-wheeler.
What experience have the experts here had with rejeting a carb for hauling aproximately 30% more weight. My guess is to take it a little leaner?
Pete
Doesn't your bike have fuel injection?
If so it will require recalibration if intake or exhaust mods are preformed.
If you are carbureted the best mixture for power will remain the same regardless of the weight of the rig. On my '03 rig (carburated) I doubled up on the Orings to adjust needle heigth with stock jets. This was after adding K&N air filter and SE exhaust. It ran a bit rich but the power was there and gas mileage didn't change much. The only problem I noticed was a tendency to flood if I touched the throttle when attempting a hot start at high altitude. OK as long as I didn't add gas.
It ran strong with or without the hack.
My Stage II RK/TLE rig was dyno tuned after it's SE mods. Cam, carb, exhaust and ignition.
Lonnie
Thanks for the reply. I like my carb evo because I can work on it. Has a little over 50K miles now.
The only tools I could use to work on a fuel injected model are a cell phone and a credit card.:>)
I have the SE air cleaner and exhaust, will probably take the main back to a 180 and see.
Thanks again.
Pete
I have a '96 Heritage, with a Liberty sidecar. Originally, the carb was switched out with an S&S, the bike was cammed, I put in a single fire ignition, it has a high flow air cleaner, and a modified HD exhaust. When I added the Liberty, I did not have to make any carb changes.
I have over 75K on the bike.
When I do need an engine overhaul, I will change cams, since the cam I am now using is not efficient for the weight of the bike. I use an EV27 Andrews cam, and I will change that out to an EV13 cam. I will gain some better low end, but I am not unhappy with the power right now.
All of your mods except for the cam help out a sidehack rig.
Almost all performance cams are profiled to raise the rpm at which the motor operates giving more power at a higher rpm than stock. This change in the power curve also sacrifices low end torque at low rpm which neccessitates the need to start out at a higher engine speed to keep from stalling and as a result more need to slip the clutch to keep form a jerky start. Ergo, more clutch wear.
The stock cams are much more tractable for a sidecar rig since the need is more for low speed grunt off the line with the heavier load and less need for top end speeds attainable with a solo bike. Wind resistance alone will keep the bike from attaining the speed at which a hot cam can come into it's own in top gear.
Lonnie
If you're Evo gives you detonation under load (as many do) without the rig, it will happen more often with the load of a rig. Two thoughts. Rejet so that you're not running lean which is a factory built condition made worse by pipes and free flow filter. And, get used to riding a little higher in the power curve so that you don't lug the engine. Other than that, you should enjoy the heck out of it.
Originally written by Hack'n on 9/10/2008 6:09 PM
All of your mods except for the cam help out a sidehack rig.
Almost all performance cams are profiled to raise the rpm at which the motor operates giving more power at a higher rpm than stock. This change in the power curve also sacrifices low end torque at low rpm which neccessitates the need to start out at a higher engine speed to keep from stalling and as a result more need to slip the clutch to keep form a jerky start. Ergo, more clutch wear.
The stock cams are much more tractable for a sidecar rig since the need is more for low speed grunt off the line with the heavier load and less need for top end speeds attainable with a solo bike. Wind resistance alone will keep the bike from attaining the speed at which a hot cam can come into it's own in top gear.Lonnie
Yep, it is best for the reasons Lonnie states here to leave the stock cams, especially with a Harley. Increased HP and torque ratings on dynos can be deceptive since they are measured at high engine rpms. What is needed is the real low-end torque. Anything you do to the cams will raise that point where the cams "come in". This is something you definitely don't want with a sidecar. That's why I've left my engine stock. It works very well with a stock 88" engine. I even bought a spare pair of cylinders a couple of years ago to change to 95" but then I thought better of it since I'm very pleased with the setup I have now.
Good luck.
