.551 Cams in an EFI 1200

[Tomcatt]

Originally Posted by sportsterpaul

Good for you and thanks for sharing that as other Fuelers may benefit.

That was my thought. The "hanging idle" seems to crop up on the EFI bikes. Mine had done it off and on for a while.
Stopping and turning the ignition off and on would "fix" it, if I left the ignition off for ten seconds so the ECU could reset. An idle trim reset would sometimes help. But watching the IAC steps in real time it didn't appear to be the IAC module hanging up. IAC steps would increase at what seemed to be odd times. That went away when I de-crudded the modules' active end. It's on a threaded shaft and the stepper motors' rotation moves the "valve" in and out to control how much air flows.
The ECUs' logic doesn't seem to deal well with the modules' response being crud impeded. A shot of WD-40 into the IAC port will be a periodic maintenance thing.

[Tomcatt]

Just a follow-up before I put my Sportster up for the winter.
Un-crudding the IAC made a big difference. My auto tune runs are no longer inconsistent and my return to idle issue has gone away.
I'm back to 20 discs and an open end cap on my SuperTrapp. With better tuning the exhaust is quieter at part throttle and is now acceptable with 20 discs and the open end cap. It also smoothed the dip in VE's I had 3,500 thru 5,500 rpm with 15 or 18 or 20 discs and the closed end cap. VE's at 3,000 rpm dropped slightly while they rose and flattened from 3,500 thru 5,500. 6,000 to 7,000 rpm VE's increased ~3%.
First thing in the spring I gotta put on a new rear tire. The silver "wear indicator" is just starting to show...

[brucstoudt]

Dunlop's ?

[Tomcatt]

Originally Posted by brucstoudt

Dunlop's ?

A 170/60-17 T32 Bridgestone. I ran it at 38 psi. It had a scalloped wear pattern like the 160's I'd run had. Probably should have run it at 40 psi. BUT, it lasted much longer than the 160's, even at 38 psi. The next 170/60 T32 will be run at 40 psi which will hopefully increase its' mileage further. I have a Conti Motion 170/60 (much less $) to try first in the spring. BEST front is still clearly a 130/70-18 Bridgestone Excedra.

[Tomcatt]

My original 1275 build was intended for SE .575 cams. I didn't install them as the #2 cam on my .575s' had an end clearance issue. The drive gear was pressed on too far relative to both my original W's and my SE .551's. The #2 .575 cams' drive gear rubbed on the adjacent cams' cam to cam gears. Not good.

So, I bought a Harbor Freight 6 ton A frame press and moved the drive gear on my .575s' #2 cam. I got it so the cams' end clearance will be .002" more than my .551's and OE W's (which measure the same) so I figure that's close enough.

The .575's will go in as soon as the weather is warm enough in my garage/shop in the spring. I've got new gaskets so I'm good to go. Should be interesting to compare VE's between the .551's and .575's with no other changes but the prerequisite tuning.

[1Scooter]

I supervised my Wife as she swapped cams in her 04 1200C. W's out and Hammer 570's in. BIG IMPROVEMENT! For me, it wasn't enough. Swapped out the CV-40 for a Mikuni HSR 42. Now her 04 is an Inter Continental Ballistic Harley. She's still at 1200 and says "It's fast enough for me." You should really love your cam swap.

[sprink]

Originally Posted by Tomcatt

Should be interesting to compare VE's between the .551's and .575's with no other changes but the prerequisite tuning.

I am curious as well.