Big bore question

[Dash]

I was talking to my usual mechanic the other day and he said that there is a 816 big bore kit availble for the Hawk. The biggest one I`ve been able to find is 696 however. I say he`s full of ****

So, does anyone know what the biggest big bore kit for a hawk is?

[fabitappi]

The biggest over here in Germany is a 840 available from Thiele

http://www.thiel-motoren.de/tuning.html

[JR]

But is he using the AT engine?

[Dash]

But is he using the AT engine?

I guess so. you can`t make a Hawk 840cc I`d say. that`s a bit TOO much

edit: the same method is applied to the afrika twin 650 and the NTV, so I guess it can be done...

fabitappi, could you translate just what they do with it to get it to almost 70bhp an 80nm? my deutch is dreadfull.

[JR]

Excerpt from the Tuning program for Honda Hawk:

The Tuningstufe for Honda Hawk applies also to:
Africa twin 650, Africa twin 750, Honda NTV 650 (Revere), Honda Transalp starting from 2000 (650ccm) and Honda Douville.


Tuningvariante 1: Achievement and torque increase with series capacity and series cam shafts

Revise the combustion chambers, channels and tax times
Engine disassembly and assembly
Carburetor tuning
Increased output approx. 8-10 HP and approx. 8-10 Nm


Tuningvariante 2: Achievement and torque increase with piston +2-+3mm as well as changed cam shafts

Work like above
additionally adapt the piston on original weight
Cylinders bore and hone
Increased output approx. 15-18 HP and approx. 15 Nm with 680ccm - 700ccm capacity


Tuningvariante 2a: Achievement and torque increase with 3mm larger valves:


Work like above
additionally change the clapper seats and work on the new valves.


Tuningvariante 3: Achievement and torque increase with piston 87 - 90 mm in diameter and larger valves (+3mm)

Work as with variant 2
additionally change seat rings & channels adapt
Crankshaft housings spindle









Africa twin 750 series (Bj 92)
58 HP (43 KW) with 7600/min
61 Nm with 5800/min


Thiel - XRV750 stage 1
(Africa twin 750 RD04 Bj 92) with auxiliary air cleaner,
Series elbow union and
SR muffler with railways killer.
73 HP (54 KW) with 7300/min
76 Nm with 6100/min

[Dash]

holy cow. that is pretty amazing. and pretty expensive probably

[Dash]

Has anyone here actually installed a big bore kit on his Hawk? Because I`d like to know a few things:

1 let`s say you install a 816 big bore kit. what kind of bhp/NM would you roughly get?

2 what are the costs to go the full monty?

3 what does it do to the bike sheer indestructability? will it become less reliable? or doesn`t it make any difference?