This is my second engine Build , first one was done on own bike. More details on first one can be found on my Ownership thread.

This thread is about General conversion from 883 to 1250cc , without any Head work or cam replacement.

My second engine build was performed on my friend's bike , who dropped it with me for as long as I would want to have it.

The bike is a 2013 superlow, and has just completed 5000km, fairly new Bike I would say. It already sports a Stage one air cleaner and SE slip ons ever since it left showroom floor.

It generally would take about 10-15 man-hours of work for general conversion without all the speciality tools. With all the tools available and in experienced hands this project will take about 6-8 man-hours.
My own project took me about 10hrs , since it was my First time . Had to go through service manual several times for correct sequence of events on various assemblies , Torquing sequence etc , Torque values etc.

For this project there is also some additional work,
1. GC riser kit . ( Friend came to drop his bike, test rode mine and immideately dug the benifits of Higher GC)
2. SE exhaust Baffle removal / Modification - as the case may be while Tuning.
3. Engine tune development , since his bike has different exhaust & intake .

Do excuse the Pic quality since I am not much into photography and does not have an assistant to keep clicking every now and then.

First Pic , GC riser kit Installed. (More on that procedure some other time)


Fairly simple job to remove Exhaust & Intake manifold. Exhaust headers need to be snug fit into seal to prevent leaks on re asssembly. Header bolts are very easy to gets their threads washed or break off on slightest hint of over torque. So if you have Exhaust leak from joint on cylinder head to exhaust header avoid trying to fix the leak by tightening the bolts. Instead try to loosen the bolts and fit the flange properly into packing and retighten.



Rocker covers removed , Simple job , just remove 4 holding bolts per rocker cover and use a sharp screw driver to push into heads / rocker cover parting line. This will pop the cover open.
After rocker cover , remove the rocker assembly itself. Complex sequence of events to release the pressure of both rockers before you can loosen any bolts. trying to find TDC by rotating rear wheel so that Valves reach a place where both intak and exhaust are closed and no pressure on them from rocker side.

Also bolt removal sequence is crittical , it has 9 bolts per cylinder ( 4 Head holding bolts, 3 rocker cover to head bolts , 2 packing pressure bolts) , opening the worng set bolts first will strip off threads from others.
After rocker cover is removed , 4 more 13mm castle nuts need to be removed to detach Head from cylinders. These are most critical , and they keep head + cylinders glued to crank case. Under torque these on re assembly and soon the engine will come apart in Hollywood action movie fashion. Over torque these and on one hot day with a Hot engine you will strip the threads clean off these bolts due to thermal expansion of cylinders , and again a Hollywood action movie while you are doing 90 on Highway.


State of Piston in just 5000km. look at the fine dust deposited on piston top. In time to come this would keep ruining the rings and engine oil and at a point it would have increase compression ratio enough to have a detonating/ knocking engine.



This(below) is the Pic from my conversion which had 20418km on engine when I converted. Look at how clean the Piston is. Physically I could even read very fine small engravings (HD part number) on piston top



Ok back to conversion!
Last shot of Stock cylinders


Unboxing new Hammers!


Putting them on future duty. Forged racing Pistons are preinstalled in the clynders to make the whole assembly easier.

New pin goes in.

Circlip to be installed in piston grove. Needs patience of a monk as it keeps coming out and flying across great distances due to tention while installation.
I actually dropped one circlip inside crank case , I tied a magnet on a wooden stick , lowered it into crank case , spent some time wandering inside and luck favoured. Magnet came out with circlip drenched in engine oil.



Comparision of Head condition His VS Mine.

First two pics showing state of valves on his head. Clearly Exhaust valve has been running at very high temp and shows sign of WHite flakes and distortion. I tell every one - Do not run free flowing exhaust & filter without retuning.




Here is a shot of Heads from my conversion-
Dig the difference in colour?



Work is still in progress and further updates will be given on coming week end!
Enjoy the engine porn!