Validation of Performance Mods

taw1126

Scooter
Thursday afternoon I re-jetted the carbs on my Scrambler, replacing the factory 110's with 118's, and pulled the snorkel off. Then Friday night I removed the TORS I bought a couple of weeks ago and replaced them with a pair of Norman Hyde Togas that I got an outrageous deal on.

Saturday morning a buddy of mine brought his box-stock Scrambler over, which is nearly a twin to mine- we've both had the 500 mile service done in the last 3 weeks. We installed the TORS on his bike with no other changes. After a quick test run to make sure everything on his bike was fine and the A/F ratio was good, we took off for a (hot) afternoon ride.

About two miles into the ride we ended up at a stop light, all alone. You can guess what happened when we got a green.

I didn't get off the line all that well, but I was watching my buddy in the mirror through the first three gears and I couldn't believe how fast I was pulling away from him. I figured he either got a worse start than I did, or wasn't pulling off the line with everything he could, but that wasn't the deal...he said he was on it for everything it had and my bike just walked away like he was standing still.

The changes to my Scrambler have been made in pieces, so while I figured I was picking up some real-world performance gains, yesterday was proof that they were real.

The downside is that now I've seen the light...and I'm already looking at making additional mods to get even more power out of this bike.
 
Your post made me smile as I've been thinking about having some head work done like higher compression, port and polish etc. With Thunderbike cams, Arrow 2 into one and K&N's in place the performance is excellent but... it could be better!
 
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wiseanhyzer

Two Stroke
The downside is that now I've seen the light...and I'm already looking at making additional mods to get even more power out of this bike.


Yep. That's about right.
Even though it's already a blast to ride, it drives me crazy knowing there's more power in there ready to be unchained.
 

taw1126

Scooter
Even though it's already a blast to ride, it drives me crazy knowing there's more power in there ready to be unchained.
I'm trying to decide if I'm heading for restrictor plate removal and 130's, or if I'll be asking Santa for an airbox removal kit and 140 mains...
 

thistle66

Scooter
I'm trying to decide if I'm heading for restrictor plate removal and 130's, or if I'll be asking Santa for an airbox removal kit and 140 mains...


Go sit on santa's lap & talk nicely. PS I got the New Bonn kit and it's missing bits cos the scrambler RH side plate is different now. They didnt mention that when I purchased but sort of annoying but easy fix. I think British Customs kit has the bit to adapt for the Scrambler RH side plate being different.
 
Your post made me smile as I've been thinking about having some head work done like higher compression, port and polish etc. With Thunderbike cams, Arrow 2 into one and K&N's in place the performance is excellent but... it could be better!


I can now report... it is better, heaps better. We re-assembled the ported and shaved head today and have just got home from the regular Friday 'bike night' that we have at a mate's home. Whether a couple of glasses of red put a special shine on my impressions or the bike is now genuinely fast is hard to tell but I suspect the later. We took one mm off the head and ported and polished the ports as well as the inlet tracts and so far I am very impressed. Tomorrow, in the sober light of day, I will give it another run.
 
I can now report... it is better, heaps better. We re-assembled the ported and shaved head today and have just got home from the regular Friday 'bike night' that we have at a mate's home. Whether a couple of glasses of red put a special shine on my impressions or the bike is now genuinely fast is hard to tell but I suspect the later. We took one mm off the head and ported and polished the ports as well as the inlet tracts and so far I am very impressed. Tomorrow, in the sober light of day, I will give it another run.

Well tomorrow is come and nearly gone! A friend on his KTM 690, my son on a DRZ400 and myself on the Scram did the Harry's Hut ride this afternoon and discovered two things. My son on the DRZ is a lot faster than me on the Scram in the tight stuff but the Scram is heaps quicker as soon as the track opens up and smooths out! On the way out there is a 2km long dead flat sealed straight with only one minor cross road. The temptation to open her up was too much and here's the result... 76kg rider flat on the tank, no wind, 24 degreesC, flat strap, 185kph (115mph) indicated. Tried again on way back, exactly the same, 185kph. I'm not unhappy with that especially as it got there quite quick and just held the speed for the rest of the straight which suggests there might be more in it if I upped the gearing. Currently running one tooth down on the front and two up on the rear (17:45). I am also running Mitas EO9 knobbies front and back so it is possible that these tyres might create some rolling resistance compared to normal road based rubber. Comments on this aspect anyone?
HarrysHutride005.jpg

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HarrysHutride015.jpg
 
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Deano

Two Stroke
Hi, just joined you other scrammers, from out here in NZ. I purchased my stead from Thunderbike in Nelson NZ who do the performance cams and serious other mods. They have a great guy there now called Scott as their chief mechanic, who is soaking up all information about performance inhancing mods for Bonnevilles. If you type into google or your search of choice 'Jenks Bolts' they have a 10 page printout on tuning tips for the 865 motor. Especially good are the tips about jetting and carby settings.
Deano
 

thistle66

Scooter
Lot more carb & tuning info here, with lots of real world examples http://www.triumphrat.net/1097253-post2.html

Hi, just joined you other scrammers, from out here in NZ. I purchased my stead from Thunderbike in Nelson NZ who do the performance cams and serious other mods. They have a great guy there now called Scott as their chief mechanic, who is soaking up all information about performance inhancing mods for Bonnevilles. If you type into google or your search of choice 'Jenks Bolts' they have a 10 page printout on tuning tips for the 865 motor. Especially good are the tips about jetting and carby settings.
Deano
 
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