Hi! I have one Thunder Tiger Ducati Desmosedici nitro bike.
I'm curious about converting original PRO12BK engine to other .12 or bigger engine
and equipping 2 speed transmission.
Is there someone who did these conversions?
Please let me know how to do !

try the guys at the link below, there's not a lot of bikers on this forum.

http://www.rcgroups.com/motorcycles-183/

but i know you can swap it for any small block engine, ie a .12, .15 or .18 as long as you can fit the head in. it's been done before. i know Novarossi make an engine specifically for nitro bikes, but there website regarding them is still under construction.


http://www.novarossi.it/products/eng...ex-onroad.html

Bruce also has a few different TTR engines as well as a Picco on his website you can buy to drop in.

http://2wheelhobbies.com/index.php?c...55362165f92947

You can fit any engine in the TT nitro that you can physically get in the frame.

If you get a replacement with a slide carb rather than a rotary one,you'll need to rearrange the linkages somehow,using a rotary carb would be a lot less trouble.
Also be aware that engines with a pull start fitted will need the plastic pull start removing or the engine won't go in the frame,on engines such as a Rossi and possibly the Picco engine,removing the plastic pull start assembly exposes the loose pull starting shaft that runs in the internal one way bearing,so unless you can make a new backplate and starter shaft you won't be able to use the engine.I made a backplate conversion for the Rossi engine in the TT nitro we race.

Your best bet is probably one of the OS range of pull start engines,removing the plastic pull start exposes the starting shaft,but it will not come out of the engine,so all you need is the one way bearing fitting on the end of your starting wand.

Allan

Thank dicko for the info of rcgroups and Novarossi.
I'm expecting Novarossi's moto engines to come out soon.

And thank Alan for the info of "backplate conversions".

That　is a very problem I have to solve,
and I have been in difficulties because I have no tools
to make such a roto start backplate to fit with new engines.

I found an article about Thunder tiger's original backplate
in 2WheelHobbies.com, and written there,
"Fits Pro .12 and .18 and Evo .12."

So,　for the time being,
TT's Evo-12 or Pro-18 engine is very likely to me.
but perhaps I have to wait Novarossi engines
if they'll come out soon and fitted with tiny roto start backplate.

If you look at your bike and look how much room there is between the frame and the engine backplate,that will give you some idea of what you can fit in there,that's why I suggested an OS pull start engine with the plastic pull start removed.

A picture of a TT.12 with the TT pull start backplate fitted.The backplate was turned to remove the surplus pull start lugs.
There has been a Rossi.12 fitted since this picture was taken.


Homemade Rossi backplate conversion.


Allan

Thank Allan very much.
Now I see photos.

In this way,
you run your bike with having exposed a starting shaft without plastic pull start,
and attach one way ball bearing only at the time of starting engine, right?

You've got it,the one way bearing is attached to the end of the starter wand.
We use an aircraft type 12 volt starter,electric drills are poor engine starters,they're too slow and tend to break one way bearings.

Allan

Thank you　Allan, I understood it.

I did not get thought by a simple method till you taught me.

I pick up an engine first of all and try to change it.

Thank you very much!