Jackshaft

[Deye76]

Got a new starter for the FXR. See they offer a one piece jackshaft. What's the deal on these besides a easier install? Kind of pricey, are they worth it?

[pwmorris]

Yes, for high HP applications.
https://www.allballsracing.com/79-2105.html
Make sure you start the bike with a very strong battery, cables, starter, etc.
One piece JS is just one more piece to a successful recipe, and a bit of insurance should there be any kickback or failed motor start under load.

[Deye76]

Thank you. That's the one I was looking at.

[hbkeith]

Hey Deye , was the stock starter having hard time spinning the 113 ? what did you replace it with ?

[turboprop]

Got a new starter for the FXR. See they offer a one piece jackshaft. What's the deal on these besides a easier install? Kind of pricey, are they worth it?

Have heard a couple of our mutual friends proclaim the wonders the one-piece shafts. I put one in my red bike, didn't see any noticeable difference. From a manufacturing perspective, the one-piece design has got to cost much less to manufacture and sell. 

[pwmorris]

I learned about the one piece JS from a couple Outlaw AMRA racers as well as an old SP AHDRA racer. After destroying a couple of mine with weak starters and understand the hard way the violence and kickback big HP motors do, (both street and race bikes), I have run them exclusively and no issues since....again, just a little more insurance, and less parts to fail during the starting process. Eliminate a weak link and move on.
Of course if you have EZ's it's a different conversation as they are a complete engine starting game changer.

[DresserDan]

What does this do for kick back?

[pwmorris]

The whole starting system takes a beating, not just the ring gear and starter.
The coupling, spring design was engineered for 60 HP Evos, not more than double that.
Stock bikes or bikes that have EZ's, its a different game.

[Deye76]

Hey Deye , was the stock starter having hard time spinning the 113 ? what did you replace it with ?

A stock starter in good shape IME will spin a 113" ok as long as you have compression releases. My starter spins good provided the compression releases are engaged. Being it's 27 years old, I think it makes sense to replace. If I still had the 80" motor, I probably would run the OE.  The new one is a All Balls 1.7. Going to replace the relay as I assume it's old too, and may as well go with AB jackshaft while I'm at it. Have a new LI battery and Terry cables already, so should be a healthy system.

[pwmorris]

Hey Deye , was the stock starter having hard time spinning the 113 ? what did you replace it with ?

A stock starter in good shape IME will spin a 113" ok as long as you have compression releases. My starter spins good provided the compression releases are engaged. Being it's 27 years old, I think it makes sense to replace. If I still had the 80" motor, I probably would run the OE.  The new one is a All Balls 1.7. Going to replace the relay as I assume it's old too, and may as well go with AB jackshaft while I'm at it. Have a new LI battery and Terry cables already, so should be a healthy system.

[ecir50]

My only beef is no locking tabs for the bolts but it does have some kind of tapered washers that suspect serves the same purpose. If your starter uses the smaller screw don't put it tight snapped the threads in the starter once luckily had a spare and the stud came out the starter easy.