BritTwit
VIP MEMBER
- Joined
- Aug 25, 2009
- Messages
- 4,067

Glen,
Certainly you’re correct.
There are many stories about hot rodding efforts gone wrong, through overreaching for too much at once.
I built quite a few Kawasaki and Suzuki four cylinder race motors back in the day and experienced that first hand.
The most effective way to build-up a motor is from a proven, conservative approach.
That’s why my initial suggestion for the 961 is simply to free up the stock, strangled, suffocated induction and exhaust.
Given what I see and have experienced with my 961, these two areas offer the easiest, least expensive avenue for improvement.
And this requires no cam changes or head work of any kind, which usually complicate matters.
In that state, with a Power Commander available, it should be fairly easy to extract another 10 HP over the stock setup.
Careful dyno work will preserve the midrange and torque curve.
Also, my experience, albeit with carb builds, is that freeing up engine breathing = better overall throttle response. A nice benefit.
I also own a Hinckley Bonneville 865 T100, with TPUSA 813 cams, airbox mods, free flowing exhaust.
Pretty conservative improvements, but it pulls far better than stock.
The 813 split lope cams preserve the original midrange, but from 4500 rpm up they totally transform the bike.
A stock 865 Bonneville will struggle to reach the 7000 rpm redline, in any gear.
I can bounce the needle off the redline now, and often smoked a buddy who had a stock Thruxton 865.
Building power in these twins isn’t rocket science; it just requires that you begin with reasonable expectations.
Certainly you’re correct.
There are many stories about hot rodding efforts gone wrong, through overreaching for too much at once.
I built quite a few Kawasaki and Suzuki four cylinder race motors back in the day and experienced that first hand.
The most effective way to build-up a motor is from a proven, conservative approach.
That’s why my initial suggestion for the 961 is simply to free up the stock, strangled, suffocated induction and exhaust.
Given what I see and have experienced with my 961, these two areas offer the easiest, least expensive avenue for improvement.
And this requires no cam changes or head work of any kind, which usually complicate matters.
In that state, with a Power Commander available, it should be fairly easy to extract another 10 HP over the stock setup.
Careful dyno work will preserve the midrange and torque curve.
Also, my experience, albeit with carb builds, is that freeing up engine breathing = better overall throttle response. A nice benefit.
I also own a Hinckley Bonneville 865 T100, with TPUSA 813 cams, airbox mods, free flowing exhaust.
Pretty conservative improvements, but it pulls far better than stock.
The 813 split lope cams preserve the original midrange, but from 4500 rpm up they totally transform the bike.
A stock 865 Bonneville will struggle to reach the 7000 rpm redline, in any gear.
I can bounce the needle off the redline now, and often smoked a buddy who had a stock Thruxton 865.
Building power in these twins isn’t rocket science; it just requires that you begin with reasonable expectations.