Author Topic: Motocross seat conversion for Yam DT1?  (Read 650 times)

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Offline John Orchard

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Motocross seat conversion for Yam DT1?
« on: February 14, 2019, 10:06:36 AM »
Anyone got any ideas (or even something for sale?) for a narrower & taller seat for my race DT1?

Thanks in advance :-)
Johnny O - Tahition_Red factory rider.

Offline jimg1au

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Re: Motocross seat conversion for Yam DT1?
« Reply #1 on: February 14, 2019, 08:49:50 PM »
matcho mick makes a fiberglass base for dt1 might be able to mod it to suit
jim

Offline OverTheHill

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Re: Motocross seat conversion for Yam DT1?
« Reply #2 on: February 14, 2019, 08:58:04 PM »
They're quite wide around where the seat latches down. On two of mine i cut a bit out of the subframe which then opened up a lot of possibilities. I used a DT175 seat on one & a PE250 seat on another. Actualy one was a YZ250A frame so think that was narrower to start with & had the DT175 seat on that. shocks will be angles in slightly at the top but mine handled it ok. My old rat bike 360 in the link to the clutch lifter pics of mine had that one narrowed. Guards obviously too high & not sure what seat i had on then. bikes long gone [i miss it boohoo]. My other long legged one i shortened the subframe & narrowed it & used a PE250 seat, but nowdays i have a TT250 seat but is too wide to get serious about for racing, seat weighs nothing though despite its size. You won't be shortening the subframe though as canted forward shocks at the top are probably ruled out for the age group of your bike. What i did to my square swing/arm was lengthen it an inch & step it up an inch which is what was going on in the USA. This effectively raked the front out a bit more & lowered the back. Nowdays that's all backward thinking & i'd probably lengthen it an inch but inline with the arm which wouldn't do much to the front or maybe fractionally pull the front back a whisker simply buy the rear being slightly higher seeing the arm isn't level but pointing down hill slightly at the axle [till ya sit on it]. [gotta remember which forum i'm on lol]. Easiest way for me to put a pic up is to link it to other forum. Funny looking at old post, dangerous things i did with an arc welder. You've prably seen these pics before. I see its an RT1 top end in the pics but nowdays it's an RT2 last time i looked!!. Pics lower down not relevant to this story is a Honda 200 motor [parts motor] in a PE250 frame although probably doesn't look PE. PE seat is what i used to use on the Yam. Just thinking, find a pic of a YZ250 or 360A & they originaly had quite a tall seat. Finding a seat would be unlikely & also the YZ rear frame is narrower than DT1.
https://www.yamaha-enduros.com/index.php/forums/1968-71-badge-bikes/2350-gas-girlings-into-pe250-shock-bodies-on-a-long-legged-rt1#20449
Sorry for the essay haha.

Offline OverTheHill

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Re: Motocross seat conversion for Yam DT1?
« Reply #3 on: February 14, 2019, 09:05:37 PM »
Oh, forgot, i use or used to use an AT1 [CT1] tank as look the same but slightly smaller & shorter so front of seat sits forward an inch or two from original which isn't a bad thing & get your weight over the front for tight turns. Plastic honda tank i used on my old short shock 360 was good & comfy but had to remove the original yamy front tank mounts.

Offline John Orchard

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Re: Motocross seat conversion for Yam DT1?
« Reply #4 on: February 15, 2019, 09:32:15 AM »
Wow Morley, you are a true Kiwi, love the 'mix n match". My Wife laughs at me because l have to modify everything, you will spin her out ;-)

Friends don't let friends ride stock.
Johnny O - Tahition_Red factory rider.

Offline sleepy

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Re: Motocross seat conversion for Yam DT1?
« Reply #5 on: February 16, 2019, 10:11:54 AM »
Last one I helped turn into an MXer had to modify the rails under the seat. The width at the shocks stayed the same but the top rails needed to be straightened to match the seat base. Not sure what the seat was as I only had the welding/modifying job.

You could always do what we did as kids back in 1970 when needing a better seat. Duct tape a piece of foam from an old sofa to the top of the worn-out stoker and keep riding. 

Offline crossedup2

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Re: Motocross seat conversion for Yam DT1?
« Reply #6 on: February 17, 2019, 12:22:28 PM »
So I run a AT1 tank with an 1979 XL250 seat.

You need to weld bracket to the frame to make it work but plenty around. Good length with the smaller tank.

Note to Self. If I did this conversion again I would move the tap on the tank 5 cm back as it hits the cylinder head.

MX250 seat would be the best choice.

Peter B
Anything Yamaha. AT1, CT1 (X3), RT1, DT3 (x3), YZ125X,  YZ250E, YZ400D, IT175E, IT250H, IT490K . Always looking for Pre 78 Yamaha stuff....

Offline Iain Cameron

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Re: Motocross seat conversion for Yam DT1?
« Reply #7 on: February 19, 2019, 09:44:43 PM »
Ive used a DT2MX seat on one and the other a TM125 Suzuki seat the DT2MX one I had to take a bit (3/4 inch out of the rear loop and press the rails together and reweld .
Yamaha tragic ; dt1, rt1, dt2, rt2, dt2mx , rt2mx , mx250, mx360,sc500, 74dt125, yzx125, yzc250, yzc400, yzd250, yzd400, yzh250, yzh80 , dt100 , xr75 ko xr80 03 , it175 82 . Not a member of any club

Offline John Orchard

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Re: Motocross seat conversion for Yam DT1?
« Reply #8 on: March 04, 2019, 09:32:05 AM »
All sorted now, Ron Whitmore helped me out with an old RM125A,B,C seat that only needed a slight reshape of the front mount bracket.

Pit-Replica in Tailand are making me a cover with the 'RM125' removed from the side and putting YAMAHA across the back.
Johnny O - Tahition_Red factory rider.

Offline topari

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Re: Motocross seat conversion for Yam DT1?
« Reply #9 on: March 06, 2019, 05:00:15 PM »
All sorted now, Ron Whitmore helped me out with an old RM125A,B,C seat that only needed a slight reshape of the front mount bracket.

Pit-Replica in Tailand are making me a cover with the 'RM125' removed from the side and putting YAMAHA across the back.


Are you able to post a photo of the seat? I have a DT250B and this seat maybe an option. Thanks.
topari

1979 IT400F, 1984 kdx200