Maybe the hole in the combustion chamber for the compression release is creating some unwanted turbulence in the combustion process. Also, were the same thickness of head gaskets used to reassemble after the installation. Just thinking out loud.

 

Fair enough Bob...

For grins, I ran the #'s on the BB's calcualtor. ASSuming 85cc chambers and .052 stock head gaskets, the static net is 9.6:1 COLD and 9.28:1 HOT.

You may be onto something with installing the CR's with the heads installed. I heard that there is a relatively new Svc Bulletin authorizing dealerships to add CR's for 07 bikes with cronic hard starting issues. Now... that;s a chickensh1t solution to a "symotom" - but does not directly address the underlying problem.

I also agree that an air leak could certainly fool the sensors into thinking there's a lean situation and subsequently causing an overly rich condition. In my opinion, the sensors are part of the control system for the EMC and ultimately fuel delivery, so it still falls under the umbrella of "tune".

 

don't know what harley is thinking using a cam with a 25* intake close on a kit that makes 9.8 static compression...no way I'd run more than 9.3 with that cam...there are so many better choices for a 103 with stock heads

 

I had the Dave Mackie Mega-Sphere 95" kit installed complete with a 030 head gasket, the TC590 gear drive cams. On my 01 Fatboy.The shop that did it for me can't tell me anything. Don't ask why I went there. I'm wondering what the ratio is. I went to the Wild Boyz page calculator, but couldn't figure it out. May be some of you have an idea?

 

it's hard to say what your compression is with those custom shaped pistons and heads...you could do a compression test or call mackie...with those cams I'll bet you're somewhere between 9.8 and 10.2

 

Thanks skyhook

 

Hey phatboy, what were your results on that build? I spoke with Dave about building a 95 and he seemed very smart! Just curious how his set up works!

 

I'm happy so far Chad. I have had to install a better starter, no compression releases, and now am adding a new Screamin Eagle HIflow pump and Baisley spring. It started wet sumping at 3000 miles. I should have done it all at the same time. I haven't really done but 1 small burnout. But seems to run real hard, it wants to go. Can't wait to get all these little bugs out of it. I had the complete kit installed. And a high pressure spring in the clutch. Guess the tranny will probably be next. I think it is the next weak spot. I also added a 48mm TB and open air AC with Vane & Hines Big Radius 2-1 and PCIII. Pushing 97 TQ

 

CRs should in no way cause a loss in economy or performance for that matter. Something else is going on. If the heads were pulled to drill the holes, betting that something is not right such and intake leak, exhaust leak or some other gremlin, all impacting the tune. Did the dealer say anything about enrichening the tune to aid in hot starts, there is a fuel adder feature for this but maybe they screwed somthing else up? Go back and try to get all the details what they did, did they pull the heads or drill the holes with the heads in place, did they change the tune in any way, any other little "tweaks" they may have done and then maybe we can give a more educated answer.

 

Keep in mind the actual hole drilled through the head in like a #60 drill bit (very small) - unless the release is leaking, hard to cause any sort of problems. As others, would guess the installer did something - leak, etc.