Silence please KX60 or the Power and the Decibels

The young Bloke has a 1999-2000 KX60, now these are essentially the exactly same bike for over a decade so parts are plentiful, the three big problems with this bike are:

*No low end power, these are your old style :”nothing nothing nothing, zap now your sitting on yer arse” style of power, not exactly condusive to a young bloke learning the clutch, gears and starting his single track adventures with the old man, he reckons his KTM50s had way more off the pipe and the kx hits too hard, too late.

*NOISE, this thing is loud, way too loud, too loud to ride anywhere near normal people, so we repacked the stock crappy steel cylindrical silencer,it made no difference could even hear him over me even when I was on the pipe.

*Front brakes, he’s just come off two KTM Pro-seniors with brembo brakes that would turn you inside out, the KX has this stiff drum setup that is worse than a joke, honestly I think my 1979 YZ80 had better stoppers and it has after a series of nasty crashes turned his confidence right down.

Now I have had a very dead lateish KX125 lying around for quite some time now, sold the front end and have been scavenging bits and pieces for other bikes off it here and there and had a near new FMF Turbine core silencer on it, got me thinking a little bit about stuff, so i went back to my “tuning 2 strokes for power and racing” manual I’ve had since a kid and did some sums, maybe the info is a bit dated, but then so is the engines basic design, so should be a good change and certainly wouldn’t make it worse from what I could deduce. So yesterday I started the project. Cut the existing silencer off the stinger section of the stock pipe, pulled the standard KX/RM FMF silencer apart and started cutting, shortening, repacking and rejigging. well a few hours later he has a ubeaut alloy and stainless repacked silencer fitted and sealed. Looks good comes out slightly shorter overall than the stock cokecan, with 50% volume increase, a shorter stinger section and a tricky little drop pipe on the end and overall only required minor underneath massaging of the right sideplate/cover and one mount actual bolted right up and with the secondary rear one we made a discreet little alloy hanger for it that tucks inside the sideplate.
So we start it…. wow this is way quiet, the obtrusive “bark bark bark” has disappeared, just a signature modern “ting ting ting”. Warmed it and gave it a rev and still really quiet, but no longer with customary kx60 pipe hesitation anymore just instant response. He gets a bit of gear on for a driveway and backyard test, and after a dozen or so laps his Mum is happier, the neighbours stihl whippersnipper is way louder and the KX has a beaut two smoker note and subdued wail onto the pipe.
He rides into the shed pulls his helmet and says, “Dad it’s way easier to take off and go through corners now” Not really understanding I just nod and hop on to go up the driveway. I instantly realise what he means it has bulk more lowend, just let the clutch out and it chugs away, whereas before all scream and slip to get my 95kgs off the mark, so I go up the drive turn around and nail it in 2nd, and the prick of a thing tries to rip my arms off instantly. Now any adult who’s ridden a KX60 knows these are upper mid hitters and will flip you over, well aware of that I always sit forward and hunch over the bars on it, still it accelerated hard with the front hovering a foot or so off the cement, so I did a few laps of the yard in third. Cornering I realised what he meant, coming out no need to fan the clutch or jam it back into second it just pulled straight onto the pipe, coming in a far bit earlier and stronger with less hit, if that makes sense, it has a stronger longer spread of power, that would’ve doubted it would’ve achieved without porting mods. Much much more than I sorta reckoned it would help the power as the formula for better low power includes a larger dia silencer with better resonance.

So with one little change, albiet a considered change problem 1 and 2 are fixed, now has anyone aware of a disc brake front that I could slip uner it?
Sometimes the gods smile upon you………..

Bruce C.