I have a 2003 XLH 883 converted to 1200. I have had a hard time getting rid of decel pop and I get a valve rattle from time to time taking of from a stop. Is there a difference in the 883 and 1200 spark module? I used the 883 heads with Weisco pistons/rings. My jets are 45 and 180. Air filter is round 6" high flow with Kraft high flow exhaust.

 

do a compression check , if you didnt radious the heads to match the extra size of the hole , it can cause detonation..
btw , I dont think there is any diffrence in the ignition..

 

There is a difference in the ignition modules - primarily, the 883 has a more agressive advance curve, and a 6K rev limit, where the stock 1200 module of that era has a 5500?? (might be 5200) RPM rev limit. If you used conversion pistons during your 883-1200 conversion, and retarded the initial advance per the directions, you should be fine. If not - you've still got some work to do.

 

Used the conversion pistons so I could use the 883 heads. I did not recieve any directions on the timing. Can you tell me what is needed or point me in the right direction?

 

If your now 1200 has 9.5:1 compression, it is going to have a tendency to want to ping if the timing is still set for an 883 (20 degrees at 1000 rpm idle). If you are still running 87 octane, the first thing to do is switch to 91+ octane, then use a timing light to set your timing to about 17 or 18 degrees at 1000 rpm idle.

 

What cHarley said - you can "estimate" that amount of retard by turning the module counter-clockwise (to the left as you sit facing the cam cover) about 3/8".

If you still have pinging issues - I'd suggest that cams (increased overlap to bleed off a little low-rpm cylinder pressure) and an aftermarket ignition should be your next purchase ( I like the Daytona Twin Tec, and the Ultima units).

The Andrews N4s are a real decent street cam, as are the SE .535s

 

Great. I will have to order a tach (which I wanted) so I can do this. Thanks for the help.

 

Order a tach? I can understand wanting one, but, just wanted to make sure that you didn't misunderstand the advice: A tach isn't necessary to do this initial timing adjustment.

 

I got it set at 18deg now. Need to take it on a run and see how it goes. I have my fingers crossed that it works.

 

I am having an issue with my starter skipping when I crank. This xl1200c is my first HD so I am not sure what I should look at first. The starter or the flywheel to see if there is an issue. It just seems like there is way too much compression for the starter to turn. I only have 14k miles and the bike runs great when it starts. Also the bushing that seals the shift lever to the primary cover leaks a little. Is this common and should I be alarmed and get fixed ASAP? I am coming off a CBR1000rr and I absolute love this HD. I never thought I would say that.