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Been slowly piecing together a "period custom" Harley XA for a few years now (or is it decades?). In final assembly now, drive train built, and waiting for sheet metal and a few other bits from my painter. (For the purists out there, yes, I know what isn't "correct" and original, and no, I haven't destroyed/removed a bracket, tab, or anything else that the next "caretaker" can't take advantage of if they want an "original bike.) While waiting, the bike is assembled enough that I thought I'd try to start it up. It started on the 4th kick! That said, it ran really badly, especially on the left side - SUPER rich and lots of black smoke!
The stock Linkert M17 carbs use fixed 320 high speed jet with a "fixed" high speed needle screwed all the way in to shut off the needle hole from supplying any gas. Instead of a high speed adjustment knob, there is simply a plug that screws in on top of the needle to hold it in place. I was missing the high speed needle assembly for one carb so thought I'd just use a standard adjustable high speed needle in both (for consistency side to side) screwed all the way in. Seemed like an easy solution. What I hadn't noticed was that the bottom of the high speed needle knob actually hit the Linkert carb body slightly before the needle was fully seated all the way leaving the left side needle with almost a 1/16" to go and the right side needle about half that! Net-net, super rich running with the left side way worse than the right! It took me a while to find the problem but a quick chuck in a lathe to remove a bit of the bottom of the needle knobs fixed it. Starts easy and seems to run well. Still haven't ridden it, but should be soon. Not sure what other models use a fixed high speed jet, but something to be aware of if you go down the same path....
Thanks.
Chuck S.
Started with this:
XA Basket - 01.jpg
XA Basket - 06.jpg
As of this week:
DSC09762.JPG
DSC09766.JPG
Linkert High Speed Needle Mod.jpg
The stock Linkert M17 carbs use fixed 320 high speed jet with a "fixed" high speed needle screwed all the way in to shut off the needle hole from supplying any gas. Instead of a high speed adjustment knob, there is simply a plug that screws in on top of the needle to hold it in place. I was missing the high speed needle assembly for one carb so thought I'd just use a standard adjustable high speed needle in both (for consistency side to side) screwed all the way in. Seemed like an easy solution. What I hadn't noticed was that the bottom of the high speed needle knob actually hit the Linkert carb body slightly before the needle was fully seated all the way leaving the left side needle with almost a 1/16" to go and the right side needle about half that! Net-net, super rich running with the left side way worse than the right! It took me a while to find the problem but a quick chuck in a lathe to remove a bit of the bottom of the needle knobs fixed it. Starts easy and seems to run well. Still haven't ridden it, but should be soon. Not sure what other models use a fixed high speed jet, but something to be aware of if you go down the same path....
Thanks.
Chuck S.
Started with this:
XA Basket - 01.jpg
XA Basket - 06.jpg
As of this week:
DSC09762.JPG
DSC09766.JPG
Linkert High Speed Needle Mod.jpg
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