Earlier today, there was an interesting tread on this NG by a guy from the UK. It sounded like he was having problems ironing the bugs out of his S&S 107 engine that he had installed in a 90s bagger about 5,000 miles ago. He had written frankly about his woes, perhaps a little too frankly since his entire thread has disappeared. I understand the need for moderating a NG, but that seems a bit much.

I had intended to tell him of the much more favorable experiences I have had with an S&S 107 over the past 10,000 miles, in an 86 FXRD. It has been basically trouble-free. It did vibrate a bit during the first 5,000 miles or so, but is now as smooth as silk. Gas mileage could be a little better; it gets 37-39 mpg on the road with a CV44 carb, and with a 45mm Mikuni it got a little less. With the low (120 PSI) seat pressure 'bee-hive' valve springs and .585" cam it runs quiet, and has an excellent power band. From 2000 RPM up the power really starts to come on, and peaks around 4200.

The power is so good that I am now having trouble finding a clutch to transfer the power to the road. So far, have tried a new set of Barnett discs and plates with their heavy duty spring, but it still breaks loose at WOT in 3rd, 4th and sometimes 5th gear anywhere above 3000 RPM. Am now thinking of a Scorpion, but hear the lever pressure is quite a bet more.

I replaced an S&S 96 engine with this one, and have no regrets, though the 96 is certainly not a slouch. It vibrated a bit more than the 107, especially around 2000 RPM, but low end torque was excellent, and it got mid 40s gas mileage.
Thanks,
Joe

 

This was probably the thread,
https://www.hdforums.com/forum/evo-c...-engine-2.html

 

Yup - that's it and this is me! Thanks Goat.

Hi Joe and thanks for your words. My experience has been very frustrating. I know another UK Harley owner who bought an S&S 107 almost the same week as me, but has had no problems, although he bought the basic ignition version, not the IST version I have.

Mine seems to be running much better since I fixed that broken exhaust clamp. I haven't put many miles on it since fixing it, but we have some decent weather now, so I can get out on it more. My wife and I are travelling to Slovakia early June, so I don't have long to get it just right!

I still have the original factory clutch fitted, with a Barnet spring to beef it up. It sounds as if things for me are going to get more exciting, if everything follows your experience. I may get back in touch to see how you improve your clutch!

Best wishes,