OzVMX Forum

Marque Remarks => Yamaha => Topic started by: von_sieben on November 22, 2013, 08:50:30 am

Title: ´74 MX 400?
Post by: von_sieben on November 22, 2013, 08:50:30 am
check this one, was offered on ebay and didn´t meet the reserve. said it´s a mx 400 1974. i have no experience with these bikes... but but a closer look that swingarm looks almost homemade to me.. is it really a 74 400 MX?

(http://www.stolengarage.co//pics/57.JPG)

(http://www.stolengarage.co//pics/57-1.JPG)

(http://www.stolengarage.co//pics/57-2.JPG)

(http://www.stolengarage.co//pics/57-3.JPG)
Title: Re: ´74 MX 400?
Post by: OverTheHill on November 22, 2013, 09:29:30 am
looks like my "75 MX250B [i had new & wish i still had it!!] with the flat sided swinging arm mono piece drilled to save weight. Interesting to see how far forward of the s/arm pivot point the front sprocket was in those days.
Title: Re: ´74 MX 400?
Post by: Iain Cameron on November 22, 2013, 08:11:42 pm
It is a mx400 but they are a 75 . The drilled swing arm is a stupid idea how in hell is water or dirt to stay out . nice bike though how much was the reserve . They have a great power spread like a tractor . Iain
Title: Re: ´74 MX 400?
Post by: von_sieben on November 27, 2013, 12:11:36 pm
don´t know how much the reserve was, seems like maybe 2000 euro or so.
http://www.ebay.de/itm/111213954595?ssPageName=STRK:MEDWX:IT&_trksid=p3984.m1435.l2649

It is a mx400 but they are a 75 . The drilled swing arm is a stupid idea how in hell is water or dirt to stay out . nice bike though how much was the reserve . They have a great power spread like a tractor . Iain
Title: Re: ´74 MX 400?
Post by: firko on November 27, 2013, 01:03:52 pm
This one's a better buy and a hell of a lot easier to ship to Oz....even if he does live in the boonies as we've found out.
                                                                            http://www.vintagemx.us/cgi-bin/largephoto.cgi?C=oQYrepYS1JzDHsUc  (http://www.vintagemx.us/cgi-bin/largephoto.cgi?C=oQYrepYS1JzDHsUc)
                                                                            (http://i1112.photobucket.com/albums/k495/firko2/firko2001/mx400b_zps170b26fa.jpg) (http://s1112.photobucket.com/user/firko2/media/firko2001/mx400b_zps170b26fa.jpg.html)
Title: Re: ´74 MX 400?
Post by: Bigjohno on January 15, 2014, 04:40:05 pm
Hey Guys I have 1 of these MX400's that I ride every weekend, what sort of $$$ r good original bikes bringing here in OZ?
Title: Re: ´74 MX 400?
Post by: Slakewell on January 15, 2014, 05:10:28 pm
Hey Guys I have 1 of these MX400's that I ride every weekend, what sort of $$$ r good original bikes bringing here in OZ?

Unrestored but running and all together would be 2.5k to 3.5k
Title: Re: ´74 MX 400?
Post by: Bigjohno on January 15, 2014, 09:27:19 pm
 Thx m8, mine is my main ride, my TT500's r 2 heavy. I love it.  :)
Title: Re: ´74 MX 400?
Post by: firko on January 15, 2014, 09:41:54 pm
Besides the RT2MX this is my favourite model Yamaha motocrosser. They're not only as pretty as a picture, they go like all buggery.
Title: Re: ´74 MX 400?
Post by: Bigjohno on January 15, 2014, 10:06:42 pm
Whats not pretty about em, lol?   :'( mine seems 2 be totally original, even the exhaust. A heap of the local youngins r in awe of it
 
Title: Re: ´74 MX 400?
Post by: mudguard on January 15, 2014, 10:20:35 pm
Would be interested to know if the aftermarket exhaust makes better performance then the original exhaust? Wonder what make it is and if there any available anywhere?
Title: Re: ´74 MX 400?
Post by: Bigjohno on January 16, 2014, 02:49:29 am
What was the correct colour 4 the frame , 1 of the bikes on this post has a Silver/grey frame & other black?
Title: Re: ´74 MX 400?
Post by: mustanggrahame on January 16, 2014, 05:36:42 am
Black
Title: Re: ´74 MX 400?
Post by: Ktm181 on January 16, 2014, 03:06:02 pm

Hmm, MX400, how or where do they fit in in Yamahas model line up, YZA, YZB, YZC, YZD etc the YZB appears to be 75 model in u.s. and sort of 74ish in Oz, was the MX400 just an extra model? How does the mx400 compare performance wise against YZC etc????  How different is the mx400 to the Yz line (engine and forks at least look like swap overs....)????

The ONLY Yamaha i have owned, ever, was a YZA!

Cheers,
Kt.
Title: Re: ´74 MX 400?
Post by: Rossvickicampbell on January 16, 2014, 04:02:02 pm
I know the MX bikes were intended, at one point, for those who couldn't buy the YZB models (not that readily available).  So entirely different model altogether - stopped in 77 didn't they?????????
Title: Re: ´74 MX 400?
Post by: Iain Cameron on January 16, 2014, 06:30:28 pm
In 75 there where no large YZ 's made , the 250 and 400 MXb's where to replace the mxa's they share the first 3 digits on the eng and frame # 509-0 for the 250 and 510-0 for the 400 , the main difference is square upper rail on the swing arm and forks 35mm for the MXb and larger with the 1976 only Air canisters for the springless forks . The YZc 250 and 400 eng and frame #'s are 509-1 and the 400 is 510-1 . Iain
now were is my Anorak .
Title: Re: ´74 MX 400?
Post by: Ktm181 on January 16, 2014, 07:06:04 pm
In 75 there where no large YZ 's made , the 250 and 400 MXb's where to replace the mxa's they share the first 3 digits on the eng and frame # 509-0 for the 250 and 510-0 for the 400 , the main difference is square upper rail on the swing arm and forks 35mm for the MXb and larger with the 1976 only Air canisters for the springless forks . The YZc 250 and 400 eng and frame #'s are 509-1 and the 400 is 510-1 . Iain
now were is my Anorak .

Thanks for the replies guys,

so how much difference performance wise is there between YZB, MXB AND YZC??  Yzc and Mxb I am assuming are very similar??? 

thanks for the advice,
Kt.




Title: Re: ´74 MX 400?
Post by: Rossvickicampbell on January 16, 2014, 07:39:02 pm
and Mr Iain - when did the MX's stop?  I reckon would be a great reliable bike for pre 78 - have always liked them.
Title: Re: ´74 MX 400?
Post by: Iain Cameron on January 17, 2014, 08:25:56 pm
!975 was the last year for the larger mx bikes there was a 125 in 76 (quite a collectors item ) the 100 dt was called a mx into the 80s and in the UK the 175 was called a mx but it had lights . KTM181 the YZb was the last of the short motors (same cases as the DT1\RT1 ) the MXb's were the evolution from the long motor used in the 73 mx 250 and 360 . The YZb like the YZa where a light weight motor meaning that any part that could be drilled or made hollow was , Gears where drilled , the shafts for the gears had holes drilled down  the ctr , clutches looked like swiss cheese ,even the selector drum was drilled . The YZa and YZb were a true works copy in my opinion and small production numbers . Where as the MXb  and YZc  were sold as large number production motocrossers  the 400's had a solid motor and as reliable as a house brick ,  it had a very good spead of power almost tractorish  compared to the YZb it was a low reving motor with a very wide power band . The YZc 400 was much the same , porting was changed and I think the gears were changed slightly . Rosco they are both good bikes for pre 78 but a little short on the suspension side and heavy porkers (I campaigned a YZc400 for years ) . Iain
Title: Re: ´74 MX 400?
Post by: Iain Cameron on January 17, 2014, 08:38:22 pm
Just a side note I have read that Yamaha intended to drop the YZ from the public range in 75 -76 to keep the mx as a clubmans bike and the YZ as a works limited copy only sold to guns . Iain
Title: Re: ´74 MX 400?
Post by: Ktm181 on January 17, 2014, 08:54:38 pm
!975 was the last year for the larger mx bikes there was a 125 in 76 (quite a collectors item ) the 100 dt was called a mx into the 80s and in the UK the 175 was called a mx but it had lights . KTM181 the YZb was the last of the short motors (same cases as the DT1\RT1 ) the MXb's were the evolution from the long motor used in the 73 mx 250 and 360 . The YZb like the YZa where a light weight motor meaning that any part that could be drilled or made hollow was , Gears where drilled , the shafts for the gears had holes drilled down  the ctr , clutches looked like swiss cheese ,even the selector drum was drilled . The YZa and YZb were a true works copy in my opinion and small production numbers . Where as the MXb  and YZc  were sold as large number production motocrossers  the 400's had a solid motor and as reliable as a house brick ,  it had a very good spead of power almost tractorish  compared to the YZb it was a low reving motor with a very wide power band . The YZc 400 was much the same , porting was changed and I think the gears were changed slightly . Rosco they are both good bikes for pre 78 but a little short on the suspension side and heavy porkers (I campaigned a YZc400 for years ) . Iain

Thanks for the reply Iain,

mate superb info.  I REALLY lusted over those "cantilevers" when I was a 15 year old, hell, my mates and I even had a teacher at school nick named Miss Cantilever, some weird interpretation of how a 15 year old thought a bra worked!!!  Have longed for one ever since, a bike with cantilever rear that is, much more interesting t,han bras!  I especially like the mx400 and 400c, I stupidly passed up a very good 400c some time back, its still on my bucket list of bikes though.....

cheers,
Kt.
Title: Re: ´74 MX 400?
Post by: Iain Cameron on January 17, 2014, 11:17:34 pm
My 76 models at the moment the 250 is spread over the shed floor .  Iain
(http://i1134.photobucket.com/albums/m612/Iain_Cameron/DSC_0013.jpg)
(http://i1134.photobucket.com/albums/m612/Iain_Cameron/DSC_0011.jpg)