Ke125

[kel]

The KERS lives!
The bike survived the driveway test, no video as the wife claimed she couldnt push and video at the same time. And they say women can multitask
Have some dyno time booked for tomorrow, assuming it holds together Im hoping to see 24hp at the wheel. And if not, no problem I have a heap of excuses at the ready.

Plus Im race fit, well B grade race fit anyway. Hope to get a few laps in this weekend, but not on the KERS.

[chrisc]

Shit yeah! Will be great to see you out there again. Bring her for show and tell anyway

[kel]

So first run on the dyno didn’t go entirely to plan.
I had made a header pipe to cylinder adapter/extension to allow for finding the optimum length i.e. start out long then shorten it until we found the right peak power point. Ended up working best at the shortest length. It was worth testing but really just cost time.
First run was way rich, leaned it off and hit 22hp at 8500rpm. Figured it was too lean as power dropped at 10000 so richened up again but no more power and it wasn’t pulling smoothly. Played with needle and header as above but still refusing to rev on. It should have been making peak power at around 11k so rather frustrating. It was becoming obvious that optimum setup was going to take some work to find. We were about to start playing with the ignition curve as it had been running a flat 20 deg advance, and then the compression dropped!
The piston to bore always felt a bit tight but the Kart shop that honed it stated it was fine, Im thinking as its got hot and the ring has stuck, the giant flames blowing out the carb would tend to back this up. Oh well had always planned to strip it down after running in to check the piston …
So 22hp at 8500 is too high, but if the motor can manage that it should easily make 24hp higher in the rev range. More work to do but its looking promising.

Big thanks to the ESE boys especially TZ350

[kel]

Had a quick look at Bells book last night. My KERS power output looks strikingly similar to his RM125C test mule which makes 123psi (BMEP) in standard trim, the KERS is closer to 130psi. Bell notes "an engine like this is easy to tune for mucher higher outputs, without knocking the mid-range about too much" Have to admit I wasn't buying TZ350 comments last night about how good it was looking, but now Im a believer! A fat 24hp is on its way.

[kel]

hmm, so looks like we sucked too many fumes. Stripped the motor, its was swimming in two stroke oil but otherwise nothing out of order.
Theres an area below the boost port were the hone marks have all ready been worn away, same below and just above the exhaust port.

And theres an odd 2mm polished strip on the exhaust port side of the piston just under the ring land.

Anyone know what this is due to? More importantly why would it have developed so quickly (the motors not yet run in)

[speedpro]

I've seen near identical, but worse, marks on Gary's MB engine, aircooled with a stock fresh MB100 piston. My moter also developed similar wear but I'm using a KT100 piston. Gary's motor actually got hard to turn over and sounded like it was seizing. All it did was polish up the areas the same as yours. His also had a rub mark on the piston on the intake side each side of central. They did not line up with the intake port bridges. I used emery tape and rubbed them off leaving a cross hatch pattern on the piston. It's been running OK for a while since I did it.

[speedpro]

Straight cut primary gear? stock??

Is that a crankcase stuffer I see tucked down beside the crank?

[RMS eng]

Straight cut primary gear? stock??

Is that a crankcase stuffer I see tucked down beside the crank?

KE an KH use the same clutch as the 74-76 KX125 i have one.and that is a plate to hold the bearing in,looks like a bad hone job.

[kel]

Straight cut primary gear? stock??

Yep, stock straight cuts. As Chris points out the KE shares parts with the old KX125, guess that cats out of the bag.

[husaberg]

Yep, stock straight cuts. As Chris points out the KE shares parts with the old KX125, guess that cats out of the bag.

That's not even mentioning the multitude of internal gear ratios available

[kel]

So corrected the inlet timing and had the exhaust pipe properly fitted up (thanks Giggles) and took the KERS back to the dyno. Things started to fall into place tonight as the motor peaked at 26hp

[Gigglebutton]

26hp F/%$k You need to come round for pies on Saturday smoko

[kel]

Here we go, the product of last nights dyno time . This wasn't the best high rpm run, we hope to pick that back up with a few more adjustments.

[cotswold]

Here we go, the product of last nights dyno time . This wasn't the best high rpm run, we hope to pick that back up with a few more adjustments.

thats looking sweet,

[kel]

Well the power just keeps building, what to do?