KTM 85cc Motard build

[grnman]

OK, so you want to make your Honda CR80 go faster and produce more power

Ensure that the motor is in good shape:

New piston, new ring, the ring and bore clearance is 2 thou of an inch maximum

At this point with good jetting and a nice busicuit brown plug electrode you should see 20hp

This is what you do:

1. Bolt on an FMF Fatty Pipe

2. Put on a Keihin flat slide carburettor

3. Add a V Force reed block

You now have 24 hp and the start of a weapon

4. Run the biggest barrel possible - 85cc

5. Change to a race fuel - VP109 will give you another 1 hp

6. Machine the head to suit the high compression levels required by VP109 - research the net for this one

7. Machine 2mm - 4mm off the back of the cylinder inlet manifold to increase the crankcase compression - you now have 26hp

8. Add a Vortex programmable ignition

9. Read Eric Gorr's tuning tips and get the transfer ports altered - you now should have 28hp

10. Learn how to ride the bike with the throttle wide open at all times

 

[ringo]

My disc has arrived "work of art" , my sx 125 front caliper is here and the 4n/mm front springs!!! I think the only parts that will go in before Sunday is the springs and probably without a fork oil change :/

Also eyeballed your SXS CDI Greeny..... Looks like new mate!!!!
I'll run it back to back with the standard unit on Sunday and let you know the results!!! Then I might send it to you..... LOL.

 

[grnman]

you mean you might buy it off me... get onto those brakes and your pretty much done.

 

[ringo]

Yeah, I've already got the 15T front sprocket, 14T on the bike 49T rear and a 42T on order I reckon chuck about a 45T in the tool box and it can be geared for anywhere!!!

Looking now for a cheap 125 master cylinder and brake hose!!

Check these out:
Yamaha YZF R6 03-05 06-07 08-10 Swingarm spools Slider (eBay item 300571023490 end time 01-Jul-11 13:38:53 AEST) : Cars, Bikes, Boats

 

[grnman]

if you can see on my disc pic i have already put some plastic on the side for now.

 

[Dyer]

cant wait to see this thing on the track.

should be fast around south morang i reckon.

 

[grnman]

Caliper arrived and the brakes are now on. thats better. i ground away some of the caliper to clear the rim.

Sprayed the barrel orange.

 

[grnman]

so i didnt go to the track today through fear of the unknow with my motor being a second hand. i took it out of the bike today instead and here are a few shots.

have a look at the heat dis-coloration on the crank. it must be the big end as is only dis-colored near there. but why only on one side? it has a proX in it currently so thank god at some point it has had a rebuild as was not the original crank. it did not have any play in it however????

i ran it down the road for 5min before i pulled it out and with a 48 pilot and 128 main. the bike still would not bog but seems to be getting heaps and heaps of rich oil. i ran 30:1. what do you make of the plug color, piston and head color? looks safe to me. the motor was 'wet' everywhere when i took it apart, e.g ports reed area and plug should be safe but i think even though its not 4-stroking i should go to a 125. the barrel looks in great condition too. what does the 'dryer' and light mean in the middle of the spark plug and darker and wetter on the outside?

i had a small amount of what looks green like coolant or maybe clutch fluid that came out with the oil as a small top layer. its getting fully rebuilt now so anything should be resolved. the water pump seals go in these things. wasnt much anyway. i think there is alot to get out of this engine with some work.

oh and the new brakes are bloody fantastic! could not be happier with them. going to have to work out the front suspension at some point.

 

[dafunk]

hey grnman
blue crank caused by heat during installation

its rich but safe

coolant should be mixed with gear oil
id say it got in there after

caution during b.e. check
someimes its hard to feel the play

 

[grnman]

thanks Ron, yes it did look like it was heat from installation. the proX looks like it was working well. doesn't really matter now as the motor has been sent off today for some major engine work.

 

[ringo]

Once the crank is out you hold the small end in one hand and tap that hand with the other hand. If there is a fair noise the big end is worn.

With your mixture mate, in the first pic with the plug still in the head, there is a shade of black on one side of the centre electrode ceramic. This is pretty rich, you want to jet to the point that the centre electrode has no black and is all brown. You will still be on the rich/safe side. If it starts heading into light brown your starting to push the limits if the weather is changeable!!

[EDIT] Mate I have so enjoyed this build I bought my own!!!!! This is the best thing I've done in a long time I'm having so much fun with it!!! It's reminding of times gone by when I was much younger and crazier racing an R6 Yammie. The fact of having an engine over 1n1/2 times a PB and with 6 gears......... LOL.

 

[ringo]

one fender and one angle grinder:

 

[Turtle]

Nice looks tuff

 

[dafunk]

looks like your at the pointy end then?

 

[Turtle]

Mind the pun hey

 

[ringo]

It was one of those things that was doing my head in.. I was too scared to lay the angle grinder into it! After marking it all out with lecky tape, I laid into it. It could of been better but better than the "cut it off straight across the front" look!!!

 

[ringo]

Mine already to go for the WA titles!!!

Until I found this dodgy fix!!!!:

 

[grnman]

that bike just looks fast now! looks better with the numbers on it. it breaks up all the black it use to have. did you drill out the rear brake side of the axle and run a rod all the way threw the middle to skate board wheels? ill have to get onto that.

hopefully your paper mashay stator is the reason my CDI did not work on your bike.

 

[ringo]

Yeah mate just ground off the cap on the rear axle nut and ran a 6mm threaded rod through the axle. Still have to do the front axle and the peg sliders.

If the test goes OK I'll send that SXS CDI over dude!!!!!

Pretty happy with the overall look now, removed a heap of the monster stickers and added the black number boards. I'm not big on sponsor stickers all over the bike, eventually I'll put relatively standard KTM side & fork guard grafix on.

 

[dafunk]

bike looking very nice
stator looks a bit average
but should of been working?