Mod Rotax Senior 125!

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Postby JohnKing6 » Tue Nov 13, 2007 7:35 pm

homoskedastic_kanit wrote:This is what i have for the Max engines

I've seen a company in Germany, Straube Motorsport, i think, offering a modified Max engines called KraussMAX, it has 2 stage modification, each has 34 and 39 hp respectively, don't know where to get the information regarding the engine, maybe www.eurokart.de or google: KraussMAX. But bear in mind that these engines are not legal in most series! And the rebuild intervals is shorten from 50 to 15 hours!


I have one of the German engines which I used in open 125cc races in 2006. It's fantastically fast when it's setup. It's very sensitive to weather changes for jetting and also to chassis handling. When it's going well it's a rocket. Because we haven't got any open races now, it's has run since it was rebuilt at the end of 2006!

So, if anyone wants a 35HP rotax engine, let me know, I'd be happy to discuss a deal :-)
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Postby ken330 » Wed Nov 14, 2007 12:56 am

teamqkt wrote:ken try 162 jet for hot day n 165 for cool weather. Front 12teeth back 81 for short track(990 meters) and 82 ( 1.3km ) AT permas.


Thanks a lot man, btw where to get the 162 and 165 jet?

David had them?
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Postby James Leong » Wed Nov 14, 2007 9:06 am

Ken,

David would normally have the jets you want. In case you cannot get from him, let me know. I stock these parts all the time. When in doubt always go to your local rotax distributor. You have my number since you have contacted me before.

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Postby RocK » Wed Nov 14, 2007 4:21 pm

sprocket wrote:Buy a DD2 cylinder.Keep original for races. James, pay me commission if you make this sale.

using DD2 cylinder, you wont have any bottom end. tested that a few year ago..
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Postby sprocket » Wed Nov 14, 2007 11:04 pm

the reason you 2 are not able to get any better performance from the DD 2 cylinder is from not getting the jetting and gearing correct i would very much think so. James, you can ask one of your senior mechanic and he can tell you if you really press him. i have run them before and i can say if you spent enough time playing around with it, it can really make a significant difference. and the reason for the poor bottom end like you mentioned rock, it is because it is design for running with 2 gears, but like i said, if u spent enough time playing with the jets and gear ratios, it does really make a big significance.in my opinion james, u are sounding very much just like a marketing guy from rotax feeding off whatever the track guys are feeding you and trying to not stir the pot too much. no offence for sure everyone's gotta do what they have to do.its business right?i can fully understand and accept this. and also this is only my opinion.but then the mechanics dont have to tell you everything do they....especially when you are not always at the track every time they test...................
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Postby RocK » Thu Nov 15, 2007 12:58 am

I'll put my money on a std Max with proper jetting and gearing then a DD2 cylinder with jetting and gearing.

think in term of driving. available power band on your right foot. as a driver, i choose std every time. unless we racing on a oval. 8)
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Postby sprocket » Thu Nov 15, 2007 1:29 am

standard is fine. just like everyone else.
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Postby James Leong » Thu Nov 15, 2007 8:43 am

Well, there are two side to the coin. If you spend enough time and effort on a DD2 cylinder with a Max engine and all things equal, you may get the power you are looking for. The end result is "At what costs?"

Anyway the end result is that the engine is illegal to race in the RMC/AMC. If racing in open series is what you are thinking, then you could spend the extra RM2500-3000 getting the conversion kit. My suggestion would be to buy another 125 engine for this purpose.

There are talks that there will be other races beside the 5 rounds of RMC in Malaysia. The other races will definitely cater for the open 125cc class. So be prepared for this.

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Postby RocK » Thu Nov 15, 2007 10:22 am

James Leong wrote:The other races will definitely cater for the open 125cc class. So be prepared for this.

Tuned SuperRoK :shock:
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Postby sprocket » Thu Nov 15, 2007 12:06 pm

yes! tuned superok. more so since vortex has address some of its reliability prolems. more choices soon with KF 1 engines. open 125 class will be very interesting!
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Postby James Leong » Thu Nov 15, 2007 3:43 pm

Yes, the open class will be interesting but I understand that the KF1 engines will not be allowed for this class. So dont go out and buy those engines just yet. Wait for the regulations.

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Postby ken330 » Thu Nov 15, 2007 4:07 pm

U guys really into karting. :D

Knowledge is power,

Must absorb as much as posible.
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Postby gerald » Sun Nov 18, 2007 3:16 pm

enough of the BS, im running DD2 on standard bottom end, it is atleast 1/2 second quicker on all tracks,my weight and kart is 188kg! and im faster than all 160kg racers on every track i have been on. Tuning and gearing is the key( it has to rev) I have done 15hrs on my last piston and ring and its still quick, there is slight port timing mods done by company in US ( very minor)I am using TAG kit from Greenflag motorsports USA,these are the only mods.I have spent only $900 australian on mods.PM me if want to know more, i too had to swim through the BS before i found out for myself how to make it fly.
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Postby RocK » Sun Nov 18, 2007 5:00 pm

ya youre is quicker cuz you played your timing. I was saying just dropping a DD2 cylinder wont make it quicker.

minor mod costing A$900 :shock:
might as well go for US$300 rpm limited cut.

then again might as well get a Tuned SuperRok and keep a std Max 8)
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Postby gerald » Sun Nov 18, 2007 5:12 pm

The timing mod has not yet proven itself as an advantage as yet, the standardDD2 barrel is quicker than max barrel, if you cant get it to run quicker you are not doing it right. its faster from 7500rpm and up,this motor is otherwise stock rotax and dont forgetv im very heavy.
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