748 What’s Involved With Fitting This Kit

Good pistons but have to machine the cylinders and set up properly, good engine mod but can get very expensive. I've had 2 853 engines built now.

 

It is not immediately obvious from the eBay posting if the pistons are for a 784/SP/SPS or are unique to the 748R which had bigger valves. If they are 748R HC pistons, there is not a huge gain from putting them in 748/SP/SPS without additional head work. Not beyond a competent home mechanic but getting the right piston/valve clearance is essential. I get 133 RWHP from my track 748RS based 853 which is great fun. I believe that there are at least 2 forum members who have shoe horned a 1200 Multistrada engine into a 748 frame. Andy

 

My old boss did an 848 conversion on his 748 track bike so that's always another option for you

 

Bigger engine always cheaper and better in the long run

 

My 996 with 1098 motor.

 

There's a lot of research on the web about these kits. The pistons are a good improvement for the 748 as you can leave the crankcase assembled. You will need a pair of 888/916 94mm cylinders. They are available and not too expensive second hand. You can't bore your existing 748 cylinders as the 6mm overbore is a lot and the cylinders need to be nikasil coated.
These pistons are the same weight as the original ones so no rebalancing is required. You'll also need a new EPROM chip for the ECU to properly fuel the bigger engine. From what I have read it's a good improvement and worth the money but as others have said, maybe a second hand 996 would be cheaper.
Going to a testastretta engine is a lot of work and $/£

 

how's it running?

 

Or just buy a 1098.

 

853 motor is a sweet tune. 748 feel and revs with 916 torque and power. You can bore the 748 barrels and get them replated. Deck height is wrong using 916 barrels so they need machining to correct.
The benefit of using the Pistal kit is that the Pistons weigh the same as stock. Using 916 Pistons requires a crank balance, so the motor needs stripping rather than being a drop in mod. Uses all stock gaskets etc. 916 or ST4 base and head is all that's non stock.
Bottom end is up to the task without a problem.
I've done maybe a dozen over the years, including my own, and they're great. Much more than the numbers suggest."..
Not as popular as it used to be now the newer motors can be dropped in, but still a great mod and easily reversible.

 

Not sure what sort of result you would get with that combination.

The Pistal pistons work with the original crank to give you 854cc and the right compression. 916 pistons on a 748 crank won't work at all as the piston pin height adjusts for the longer stroke in a 916 engine. The 748 heads can be opened a little as you have an extra 14% volume and corresponding compression but I understand the original heads will work well. 916 would leave you with less compression as they are designed for 916cc

 

Good. I'm in the uk but when back in germany I will do an update on the original thread..

 

I still run my 853 on the road and it's a cracking conversion, it loves to rev and keeps on pulling until it hits the limiter. As mentioned it's quite easy to drop a larger capacity engine in if that's what you want but I can't see it being any cheaper.
Steve