Seca 750 anyone?

[daveyg]

A friend is giving me a running Seca 750 that has no title, but I'm trying to decide what to do with it. Kinda leaning toward parting it out, but part of me wants to play with it and build something funky outta it. Question is, does the driveshaft spin bassackward like the 11, or does it spin the same direction as any typical small car driveshaft? Thoughts from the group? Would it be impossible to chain drive conversion it? (If a guy knew a competent machinist) thanks y'all!

[daveyg]

I guess if I'm gonna do something crazy I could just mount the engine sideways with a hub to a sprocket mounted direct to the output shaft...

[motoman]

A friend is giving me a running Seca 750 that has no title, but I'm trying to decide what to do with it. Kinda leaning toward parting it out, but part of me wants to play with it and build something funky outta it. Question is, does the driveshaft spin bassackward like the 11, or does it spin the same direction as any typical small car driveshaft? Thoughts from the group? Would it be impossible to chain drive conversion it? (If a guy knew a competent machinist) thanks y'all!

Unless your plannin' on riding that scoot in reverse, all shafty scoots driveshafts turn same direction, no matter what side there located on.

Converting to a chain-drive.............anything is possible if your pockets are deep enough............a waste of good money IMO though.

[donebysunday]

Did they make a chain Seca 750 ?
Back in 80 something I raced a 750 Seca with my SF, let him take off in the lead thinking on this long straight I'd pass him. Never did gain any ground on him, thought it was because of the chain ?

[Prisoner6]

Did they make a chain Seca 750 ?

Hey, Unca D -

No ...

Yamaha never offered a factory-produced Seca 750 in a chain-drive version.

The Seca 650 was also a shaftie, but the Seca 550 did have chain drive.

[motoman]

Did they make a chain Seca 750 ?
Back in 80 something I raced a 750 Seca with my SF, let him take off in the lead thinking on this long straight I'd pass him. Never did gain any ground on him, thought it was because of the chain ?

Nope, quarter mile time differences between it and the XS11 comes down to less than a 'missed shift'.........unless it's a Seca turbo 750, of which there was only a few thousand produced. Definitely a stylish sport tourer 'of the day'.

[Prisoner6]

Nope, quarter mile time differences between it and the XS11 comes down to less than a 'missed shift'.........unless it's a Seca turbo 750, of which there was only a few thousand produced. Definitely a stylish sport tourer 'of the day'.

Yamaha never produced a Seca Turbo 750 ... but they did offer the Seca Turbo 650 (653cc) for the 1982-83 model years ...

[IanDMacDonald]

Yamaha never produced a Seca Turbo 750 ... but they did offer the Seca Turbo 650 (653cc) for the 1982-83 model years ...

Mmhmm. I have two. Horrible bikes.

[daveyg]

Hmmm... Interesting food for thought. Thank ye gentlemen! I'll post pics once it's in my possession.

[MindWebs]

No, they can not be converted to "chain drive".

the XS11 has a "middle drive gearbox" that can be un-bolted from the transmission, and replaced by a custom built gearbox with a chain driving sprocket.

The XJ750 Seca, has an intrigrated "middle drive", it's built into the tranny castings and cannot be un-bolted.

and good luck whooping on a 750 seca with an XS11.

unless you have a very long strait road.

the XS will pass at 125-135MPH
(XS11 approx max speed 140MPH) depending on condition of bike
(Seca approx max speed 120-130) depending on condition of bike

the Seca was originally designed as a track racer
(crotch rocket, before those existed)

the motor is solid mounted in the frame so there is zero hp lost in mounting twist.
and the timing is hotter then the maxims, and carbs are jetted slightly differently.

sweet little nasties, i like them .

i own both and prefer the seca as my daily driver.

but, as you notice i am very bias toward the seca....

it'd the difference between a battle axe and a war hatchet. (xs11 to 750 seca).

[daveyg]

Yeah I've come to the realization that the 'middle drive' is housed in the case. But I'm not thinking of a motorcycle, I'm thinking mounting engine longitudinally in say, a go kart/sandrail with a sprocket mounted off the shaft flange, running to a solid straight axle rear shaft. I've got a spare axle off a Honda 'big red' ATC 200 that would make a great donor. Thinking 2 seats side by side, atv tires front n rear. Just thinking right now though, I don't even have the bike in my possession yet.

[MindWebs]

how about a C.V. shaft axel off a big 4 wheeler?

then all you would need to do is adapt the drive shaft.

but there is lots of ways to set that up.

shroud the motor and put an electric fan on for cooling

that would be one mean nasty shifter cart, i alway's wanted to build something like that. put an electric solinoid for shifting, or air shifter.

switches on the stearing wheel, clutch and throttle on the floor...



i can here smell the rubber burning from here....

use a nice soft bucket seat out of a car, to help soften the ride...

Sweet!!

sounds like a blast!

[daveyg]

My thoughts exactly! Would be one hell of a mean 2 seater shifter kart! I'd build a swingarm on the rear for suspension, front I'd need to do some thinking... There's an ATV wrecker not far away that I could probably get a whole front end from.

[Brent]

Adventure

No, they can not be converted to "chain drive".

the XS11 has a "middle drive gearbox" that can be un-bolted from the transmission, and replaced by a custom built gearbox with a chain driving sprocket.

The XJ750 Seca, has an intrigrated "middle drive", it's built into the tranny castings and cannot be un-bolted.

and good luck whooping on a 750 seca with an XS11.

unless you have a very long strait road.

the XS will pass at 125-135MPH
(XS11 approx max speed 140MPH) depending on condition of bike
(Seca approx max speed 120-130) depending on condition of bike

the Seca was originally designed as a track racer
(crotch rocket, before those existed)

the motor is solid mounted in the frame so there is zero hp lost in mounting twist.
and the timing is hotter then the maxims, and carbs are jetted slightly differently.

sweet little nasties, i like them .

i own both and prefer the seca as my daily driver.

but, as you notice i am very bias toward the seca....

it'd the difference between a battle axe and a war hatchet. (xs11 to 750 seca).

I like what you have done with your Seca. It Sure looks the adventure bike part.

[MindWebs]

Twisted whiskers..

Thanks Brent.

You have some intresting machines too.. i'd imagine you have a hard time picking the machine to take that day.

i just have a hard time deciding what my machine is or what it should do.

2 sets of upgrades ago.


Newest start to madness this winter




Yes those are xs1100 rims front and back on a xj750 seca.
(not bolt in upgrades, machining required.