Building the perfect beast (KTM Maico 490 killer)

[sachsmx]

Does anyone have any hints for building a KTM 420 to be able to run with a Maico 490, riders being equal? Is there anyone out there who can port my cylinder to bring the best out of my 420? I have never ridden a 420, but have read that they make pretty decent low to mid power, which is what I want, only lots of it. Would a Lectron carb make a big difference, and, if so, can someone set up one to fit the same airbox to carb boot as my stock Bing, or sell me an airbox boot that will work?
My favorite bike (one which I have owned and ridden frequently) was a 1980 Maico 440 as it had a great balance of handling, power, and suspension (once fitted with Ohlins shocks).

[tlanders]

My 1979 MC80 with a J.P. Morgen reed cage/port job on a KTM 400 (360cc) engine beats the big Maicos every time. Hole shots, long straights, etc. A 420 modified by J.P. would be even that much better.

Teddy

[sachsmx]

Teddy, would you happen to have JP's email? What carb are you running on the 400? Is the reed mod bolt-on or welded?
Since I am investing a lot of time and $$$ in my bike, I wish to build the ultimate KTM twin shocker. I may be way off base, but I believe that the 495 KTM has the wrong bore/stroke combination for MX use.

[Big Mac]

I believe it was Replika Maschinen who hot rodded the vintage KTM motors for Morgen:  http://www.replikamaschinen.com/

See also their work on a vintage Maico- //www.ahrma.org/features/big_reed_maico.htm

If you go this route with your 420 project, you must promise to report back performance results, costs and results of Maico 490 drag races.

Jon McLean
Lake Grove, OR

[G Ellis]

I have a ported 420 cylinder. Send me your email address and I can send you some photo's. Pistons for any 420 are very hard to come by. Later Gary

[sachsmx]

Gary, I have a good top end with very low hours and wish to use it. I don't think I will go the reed valve route, as it may be more $$$ than I wish to spend, however, I would like to have my cylinder ported by a reputable individual. Any leads there would be appreciated.

[tlanders]

J.P. doesn't use email. His phone number is (415) 822-1315. He builds a bolt on reed box and uses Yamaha 6 pedal reed cages. I'm using Lectron carbs on all my Post Vintage (AHRMA) bikes. The Lectron can be ordered machined to fit whatever intake manifold/rubber diameter you need. My 400 (360cc) does a third gear wheelie start off the line and I can shift to 4th with the front wheel still in the air. Got the hole shot with it at Casey last Saturday. I believe Denny Liegerot has pistons for the 420. I know he had them made for the 495. His number is (828) 862-6773. Have fun. Building the bike is the most fun part, racing it comes in second.

Teddy