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Clubroom => Tech Talk => Topic started by: jimg1au on June 30, 2012, 07:28:49 am

Title: rotax 500 vs yamaha tt500 engines
Post by: jimg1au on June 30, 2012, 07:28:49 am
hi
i have been offered a rotax 500cc 4 stroke motor it has been rebuilt but dont know if for racing or the std trail bike motor.
i have heard that they can go well but are fragile and expencive to fix
would i be better off with my 500cc yamaha motor that has way more power than i can use
it will be used for dirt track only
jim
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: holeshot buddy on June 30, 2012, 11:53:37 am
rotax eng lighter chrome bore roller cam
they get 80hp out of them in US for flatrack
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: shortshifter on June 30, 2012, 01:28:18 pm
HB are they the engines they use in the ATKs as well?There is one for sale at a pawn shop in Nambour at the moment.
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: Lozza on June 30, 2012, 02:58:26 pm
hi
i have been offered a rotax 500cc 4 stroke motor it has been rebuilt but dont know if for racing or the std trail bike motor.
i have heard that they can go well but are fragile and expencive to fix
would i be better off with my 500cc yamaha motor that has way more power than i can use
it will be used for dirt track only
jim
Having  spent many hours playing with Rotax engines safe to say the Yamaha is trail bike engine and the Rotax a competition engine. I could probably get you the bits and pieces Jim they are well priced wen you don't go through 'middle men'  ;)
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: holeshot buddy on June 30, 2012, 05:51:28 pm
yeah the atk ran a rotax 605 eng
cam belt drive all the good stuff
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: pancho on June 30, 2012, 06:05:45 pm
 I recon stick to the XT Jim, cash the Rotax
 and keep the change!
pancho
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: mainline on June 30, 2012, 06:48:40 pm
HB are they the engines they use in the ATKs as well?There is one for sale at a pawn shop in Nambour at the moment.

Have to start hanging around the Nambour pawnshop. The local ones just have guitars with bent necks, stolen power tools, and roller skates with a wheel missing
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: oz555ktm on June 30, 2012, 11:29:07 pm
 If any one out ther  that has parts or Motor for a KTM/rotax thay dont want or are Not going to use

 Please  can you send them my way ... as I am in need of parts  for my  ktm 504

 
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: jimg1au on July 01, 2012, 06:57:17 am
Rotax Engines
 







Rotax 605 (604ES) electric start engine for sale, good used condition. Southern California. Pick up or ship UPS.





this is in ca cheap shipping to sydney once in long beach




Rotax 504/604 good used bottom end for sale, 79.4 or 81mm stroke available. Includes cases, bearings, 5-speed transmission, oil pump and new seals. . Southern California. Pick up or ship UPS.

Call for more information. Ron Wood 949-645-0393

June 30
 
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: EML on July 01, 2012, 10:39:25 am
Big arguments in UK sidecarcross at the moment is whether the Rotax is eligible for pre'85 as they clean up-much lighter than XS motors and same or better power-they wont let them use elec start model.
So if it's not reqd-send it to me. I'll even pay the freight!
 
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: 270YAM on July 01, 2012, 11:47:26 am
Vaughn, were they popular back in the day? (in sidecarcross) Or did the 2T mopeds take over?
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: TM BILL on July 01, 2012, 12:53:05 pm
HB are they the engines they use in the ATKs as well?There is one for sale at a pawn shop in Nambour at the moment.

Have to start hanging around the Nambour pawnshop. The local ones just have guitars with bent necks, stolen power tools, and roller skates with a wheel missing

 ;D ;D ;D ;D ;D ;D
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: EML on July 01, 2012, 01:04:30 pm
270, They were just getting headway when the twosmokers came in and took over. On the twinshock chair site they are debating them almost daily-whether they can or can't score points at this or that meeting etc...
The counter argument is for or against later model brakes or copy frames being allowed etc.... but for me here, where we had 500 single four strokes as a class before the onset of 2stroke moderns, they are/would be a great motor.
To me, these blokes over there that try to make their old twinny outfit try to look like a modern is just shit-there is a beautifully refurbed Norton EML that has a modern front plate and sidecar facia and that looks crap.
Back to the Rotax-they are the goods for racing and the old Yams are for trailbiking. Another goody is the Husky fourstroke with the twostroke bottom-end, very nice! 
Title: Rotax HL ?
Post by: Mick D on July 01, 2012, 01:27:58 pm
HB are they the engines they use in the ATKs as well?There is one for sale at a pawn shop in Nambour at the moment.

Geez, if I lived in south east Qld? I would be grabbing this 79 frame(pic is link).
(http://i677.photobucket.com/albums/vv132/mc125mick/KGrHqVHJDcEddrIB3BP3YZYeu0Q60_12.jpg) (http://www.ebay.com.au/itm/120938322531?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649)

Then I would be camped out side the pawn brokers door in Nambour Tonight.
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: gra1961 on July 02, 2012, 07:10:20 pm
its a complete atk at the hock shop in nambour but its not for sale .i think the owner of the bike was just getting a loan
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: euro bikes on July 07, 2012, 11:44:27 pm
It had $2500.00 on it , everything was knacked on it,don't know about the motor.
Title: Re: rotax 500 vs yamaha tt500 engines
Post by: crash n bern on July 09, 2012, 05:50:14 pm
The 500 Rotax motors in the Canam Sonics were a little underpowered, the 504's in the KTM's put out better power. The ATK's used the 605 motors.  They can pump out around 70 horses with work, don't know how well they hold together then, probably get a bit fragile, but at what cost to win a race, right?.  Stock they are very reliable, but have heard of some gearbox problems when thrashed.  Can't remember what it is that lets go though.  Had a mate that raced vintage road race and mentioned something about third gear letting go.  Met a bloke with an ATK that had a box let go as well, he rode his hard.  Parts are dear, but it looks like Lozza has a source. He probably knows more about them as well. 

Years ago I picked up a KTM 504 with a shot motor.  Bottom end seized, bore cracked, cases welded.  I got a quote for $3,500 just for the main parts I needed, let alone machining and labour and whatever sundry bits I needed.  The best solution I came up with would be to throw a Yamie 500 or 550 motor into the frame.  And before anyone asks, no the dead motor is not for sale as I have other Rotax bikes.

As for the ATK in Nambour, I paid $2,600 for a rough ATK about ten years ago, I justified it to my better half that the sum of parts was worth more than the asking price.  All she said was ""$2,600 is a lot of money for spare parts."