Thumper Club Forum

Technical => Project Progress => Topic started by: silver on May 15, 2017, 10:52:01 AM

Title: KTM 640 Supermono Build
Post by: silver on May 15, 2017, 10:52:01 AM
This is something that's going to take a while, but its progressing nicely. Best place to follow progress is on my blog  www.puddingbag35.blogspot.com
Its a RS125 chassis with KTM 640 LC4 engine. GSXR 750 forks just fitted, cooling system half done. Exhaust fabricated in my shed, looks pretty good I think.
Title: Re: KTM 640 Supermono Build
Post by: timbo on May 15, 2017, 10:56:55 PM
Great project, and great work. Thanks for posting  :)
Title: Re: KTM 640 Supermono Build
Post by: JOOLZ on May 17, 2017, 09:20:54 AM
Interesting project, looking good
Title: Re: KTM 640 Supermono Build
Post by: tommy on May 17, 2017, 09:52:00 PM
wow interesting project looking foward to following this
Title: Re: KTM 640 Supermono Build
Post by: silver on July 03, 2017, 10:46:08 AM
Getting there.

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Title: Re: KTM 640 Supermono Build
Post by: CrazyFrog on July 03, 2017, 11:14:49 AM
Wow, looking really good!  :)
Title: Re: KTM 640 Supermono Build
Post by: themoudie on July 03, 2017, 01:16:59 PM
Aye David,

Making good progress and should deliver plenty of smiles.

All the best, Bill
Title: Re: KTM 640 Supermono Build
Post by: silver on July 10, 2017, 12:25:32 PM
Well, its running now but has a few issues. Oil is spraying out of the front rocker breather, so I have ordered the gauze filter for that pipe, also the gasket for the cover and some copper washers.
Screen and new grips fitted since these pics.
Oh and ive removed the thermostat. I am not running a fan so I need to know how hot it is really getting.

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Title: Re: KTM 640 Supermono Build
Post by: timbo on July 10, 2017, 08:31:08 PM
Looks the absolute b********  :)
Title: Re: KTM 640 Supermono Build
Post by: silver on July 11, 2017, 07:44:52 AM
I went to Castle Combe on sunday and saw Guy martin ragging the Honda 250 6 round. What a sight!.
Around the pits I got chatting to a chap on a KTM supermono. It had a special tubular frame and a 610 engine making around 70 hp. He said it weighed in at 95kg..wow. It looked just like a 125. sadly I didn't see it going.
May get mine to Mallory on Friday for a quick test run.
Title: Re: KTM 640 Supermono Build
Post by: CrazyFrog on July 11, 2017, 08:14:06 AM
Silver, that really does look like the dog's do dah's mate. Hats off to you....
Title: Re: KTM 640 Supermono Build
Post by: JOOLZ on July 13, 2017, 10:26:04 AM
Wow that looks great :)
Title: Re: KTM 640 Supermono Build
Post by: silver on August 09, 2017, 01:38:52 PM
After sorting some cooling issues and killing the Li-ion battery with the starter solenoid woes,these batteries make a kind of hissing sound and a nasty stink when their time is up.
Itlooks like its going to be ok for a test run. I booked an evening trackday at Rockingham Friday 11t aug so fingers crossed.

I had two cooling pipes on the pump on the wrong spigots. While I was sorting that out I removed the thermostat and turned the outlet housing 180 deg to give  better hose run. I can now do away with one of the hoses that circulates water prior to stat opening.

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Title: Re: KTM 640 Supermono Build
Post by: silver on August 16, 2017, 07:43:21 AM
Fortunately I got to Rockingham early and had time for fettling in the car park. Tried running it through the tunnel and back but it hardly managed that under its own power. Then the starter solenoid stuck on again. Fortunately I had fitted the isolater switch. Cancelled the track evening and went home. Got a few jobs to do before I can get back on this. I haven't given up on it ....yet.
Dave
Title: Re: KTM 640 Supermono Build
Post by: silver on September 13, 2017, 12:15:01 PM
After much tinkering and swearing it is now running properly, goes well and sounds good. Looks like I cured the solenoid problem. I took the loom apart and removed all the excess wires and connectors and re bound it up. Fitted a big "sputnik" type solenoid which is good for 150A constant. Not had any bother since. Have small weep of oil from sprocket shaft seal, which I have the parts for to fix this weekend.
I ordered an R6 master cylinder but it turned out to be 14mm, so have ordered a TRX one which should be 16mm. Should sort the brakes out with new track HH pads.
 Have a trackday booked at Mallory 6th oct. Fingers crossed.
Dave
Title: Re: KTM 640 Supermono Build
Post by: silver on October 09, 2017, 02:08:59 PM
Well, I took it to Mallory on Friday having spent most of Thursday fettling. I made up a booster battery pack and fitted a new spark plug. I discovered that the ferrule on top of the spark plug was missing so it wasn't making good contact with the cap. that explained a few issues with starting and running. It now starts much easier. At Mallory all was good. It started well and ran well. Got through noise test at 92db with a baffle. Did the first session and it went really well, it stopped well handled ok and pulled well. However when I pulled in, a puddle of oil formed underneath which was from the rear shock. I pumped the rest out and tied some cloth round it to soak any up. I then decided to to add some fuel to the tank. I think the inside of the upper portion of the tank was coated in Dust/mould / crap I don't know what, but adding fuel loosened it all up and turned it into pond water. Since then it wouldn't run for more than half a lap before stopping. 30 seconds later it would go again and get me back to the pits. Tried flushing out with fuel but I could never get it clean, had to give up at lunch and went home.
It sounds like a disaster, but I felt like it was a success because the failure were not really anything to do with the build. The cooling system worked, The starter issues seem to be history, it went well and stopped well, and I enjoyed riding it, so it looks like it will be good in the future.

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Title: Re: KTM 640 Supermono Build
Post by: themoudie on October 09, 2017, 05:58:06 PM
Aye silver, sounds that with a little fettling, the job will be a good one. Enjoy the tin can free zone!☺
My regards, Bill
Title: Re: KTM 640 Supermono Build
Post by: silver on November 29, 2017, 08:36:02 AM
Had A last outing at Mallory having cleaned the tank out. Went well all day and did all 6 sessions. Handled really well, the front end is spot on. The rear shock is average, needs more preload and damping very poor. Unfortunately there are no other shocks around that will fit. all the quality replacements are £350+ might have to get a bit creative. Going to re do the exhaust mid section this winter and the Sprag clutch needs replacing.

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Title: Re: KTM 640 Supermono Build
Post by: timbo on November 29, 2017, 09:34:43 PM
Congratulations. Amazing bike  :)
Title: Re: KTM 640 Supermono Build
Post by: JOOLZ on December 15, 2017, 11:46:26 AM
Wow looks great, well done :)
Title: Re: KTM 640 Supermono Build
Post by: silver on February 06, 2018, 11:25:56 AM
Sprag clutch replaced, Bitubo rear shock rebuilt by hawk racing and link pipe remade. KTM Tach ordered and some new footpegs on order, that's it for now.
Just going to ride it this season and see what it needs.

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Title: Re: KTM 640 Supermono Build
Post by: timbo on February 07, 2018, 10:54:26 AM
Great job 😀
Title: Re: KTM 640 Supermono Build
Post by: silver on March 05, 2018, 10:17:01 AM
Last outing before the snow came was at Oulton park. Had a chance to ride a 640 supermoto and mine back to back and it confirmed the vibration on mine was just not right. The only thing I could think of was the rear engine mount which I hadn't checked when I started the project. Took it right apart at the weekend and the top hat spacers in the rear of engine cases were drilled 1mm oversize.
Will machine some new ones and see how much better it is. May move the oil cooler into the air flow while its apart.

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Title: Re: KTM 640 Supermono Build
Post by: silver on August 12, 2018, 08:36:45 AM
I have had this running well for quite a few months and done 6/7 successful trackdays. Vibration is a bit annoying otherwise it has been spot on, however in a bit of frustration over fuel leaks decided to sell it. Surprisingly it sold really quickly to someone who knows all about them. Now looking for a SZR660.
Dave
Title: Re: KTM 640 Supermono Build
Post by: CrazyFrog on August 13, 2018, 09:25:42 AM
Well, I'm pleased you managed to sell it quickly and hope you got what you wanted. Must have been difficult to part with it after all that work!