Question about piston jets

[les]

I'm starting on the up-swing on rebuilding my Millennium 114"...just started because I have the cases still split.  I currently have the stock OEM pistons jets.  I've got a Feuling oil pump and cam plate.  This might be a dumb question, but are the stock piston jets just fine?  Are there any after market jets that improve the cooling and performance that I should consider?  Thanks.

[TXChop]

Stock should be fine. The only reason i have ever changed to the S+S is for clearance reasons. 

[hdpegscraper]

When I built my 106, S&S recommended their piston jets as they provide more clearance to the bottom of the piston. That would be a 4 1/2 stroke, dont know what yours would be. When I went down to a 103 (ya I twisted a set of wheels) I put the stokers back in. I dont know if the S&S jets help, hurt, or retain the same cooling effect. But they do provide more clearance to the piston if you find that that is needed.

[HIPPO]

Some builds require the extra clearance of the aftermarket jets, it is not a option.

Since you say rebuilding, if it ran with the stock jets before and they didn't get whacked off it has enough clearance.

[Billy]

You may consider putting new stockers in while you are there, they have a pressure activated check valve in them (spring and ball IIRC) which could be worn, also the small orifice could be partially restricted or completely plugged.

[Bagger]

When I built my 106, S&S recommended their piston jets as they provide more clearance to the bottom of the piston. That would be a 4 1/2 stroke, dont know what yours would be. When I went down to a 103 (ya I twisted a set of wheels) I put the stokers back in. I dont know if the S&S jets help, hurt, or retain the same cooling effect. But they do provide more clearance to the piston if you find that that is needed.

If I may ask, why didn't you put another 4.5" crank in?  Was it a complete S&S kit (crank & pistons) that you ran?  I've read some guys have used a JIMS 4.5" crank and Harley 103" pistons.  Ok, what cam did you run with the 106?  Just trying to gather info, as I've often thought of doing a 106".

[Don D]

small orifice could be partially restricted or completely plugged.

Have seen more just hang wide open and squirt all the time. Not that easy to replace on a top end job but can be done.

[les]

Thanks for the replies.  The engine is an over-square motor with the stock 4" stroke and 4.25" bore.  I didn't think about the check valve being worn or the hole plugged...good tips.  I think I got the answer that the S&S jets are for clearance and not for any functional difference.  Again, thanks and I'll consider replacing with a new set of stock jets.

[ICANTD55]

Les
I may have a new set for you when I built the 124 I had a new set or oilers for the 114 . Now to find them.
I will check tonight when I get home.
Rick.

[hdpegscraper]

Bagger,... It was S&S flywheels, pistons, and piston oilers. Long story short, when the crank spread on the crankpin, it got bad enuf that the crankshaft brg. race on the cam side was wore down roughly .010, and that hardened material got sucked in between the piston and cylinder wall and I bet you can imagine the result. Im also sure that some of that got into the crank pin / rod area. I also didnt like the short piston skirt, not to mention the massive relief cut into the piston for piston to piston clearance. Another consideration was piston speed as I do a fair amount of freeway riding, and 85-90mph seamed to be just past the sweet spot. Heads were and still are SE pro that I reworked and had OS valves put in, got some groves in there too. Cams were and still are Wild Things 46G. As a 106 it made 119 hp & tq, STD and 100 tq @2800 and again @ 6200 on the down side. Now this was getting costly, and Zanotties and Chicago HD prices are hard to beat. So I detuned with Harley parts.    Hope that helps some.

[nc-renegade]

Have seen more just hang wide open and squirt all the time.

I had one of mine stuck open.  They are very easy to check if you have them out.  I used a air nozzle and air regulator and just increased the air pressure until the check ball released and passed the air through the jet.  IIRC, they open at 15 psi.