I have recently upgraded my 883 with a SS1250 big bore hooligan kit, heavy breather, heavy duty clutch, VH 2-1 slant exhuast. I didn't get new heads but had the exsisting heads bored to suit. It is currently being dynotuned and the technician has mentioned it runs hot due to the increased bore. Has anyone had any experience with this type of upgrade and had any problems with heat dissipation?

Increased heat typically results from increased compression. Another cause can be a mismatched cam. The size of a cylinder and the thickness of a cylinder wall shouldnt matter although increased heat on a thinner cylinder wall can create weakness in some metals. Anthing by s&s should be fine. Typically s&s cylinders' fins dissipate heat better than Harley cylinders. Tuners typically add fuel and adjust spark timing to address issues relating heat. Your heads would have been ported and had new valves installed not bored. 

Yeah, my bad. Cylinders were stock and bored for 1250,  heads were ported. Didn't get the SS Cylinders.$$$. Picked up from tuner 78hp-86ft-lb on graph. Was hoping for more after upgrades, but still significant difference in power from stock.

I've installed a Hammer performance 1250 kit with a TTS mastertune on my 883. It actually reduced the amount of heat coming from the bike. Sitting at the lights when it was stock had alot of heat pouring out. Now not so much and it is noticeable. Didn't do any work the heads - just checked crush as i was installing the kit. It was a couple of thou or two above the minimum of the tolerance so would have good tight compression. If i were you I would either A. Take the bike to a reputable tuner with harley experience or B. Buy a tuning module of your own such as the TTS or Thundermax. A tuner should nut out those backfire issues before giving the bike back to you.

bit slow on reply, just hope you sorted this out.

Thanks for your responses. Sorry for the delayed reply l have been away. Problem was sorted after fitting the Vance and Hines 2-1 Upsweep and installing the baffle ( which was on backorder for 4 months ) BOO Vance and Hines. I then returned it for a secound run on the dyno at a recommended tuner and the problem was fixed. Fitting the baffle made it sound deep and throaty and according to the dB meter l used was 93 dB at 2750rpm. Sound wise ( It’s below 97db ) it also increased my torque to around 90lbs-ft but reduced my hp. Happy as getting caught at 160km on the urban road puts this tradie out of work. 

Nice job on the design, that looks great.  What's the details on those mirrors?

Nice bike mate, well done on the style and the engine mods! TC