CustomFighters.com Streetfighter Motorcycle Forum > 1978 XS400 CAFE Build

Crom_child · 03-06-2012, 01:49 PM

Real nice work... clean bike

XS400 DOHC motor being bored to accept GS500 liners & pistons ...

Left is GS500 piston 1 mm o/s, right is XS400 dohc stock piston @ 69mm.

Garlic_Sauce · 03-06-2012, 03:12 PM

Thanks. ^^^^^Nice dude, keep me posted on how it turns out.

Sinister Imaging · 03-06-2012, 04:09 PM

I want to do a big bore on mine too!!!!!

Crom_child · 03-06-2012, 10:41 PM

Dunno who owns the whole hog DOHC XS400/GS500 hybrid motor.

Hell of an upgrade...
Saw the machining pics on Photobucket.

Let's see an XS under 400 lbs. w/ 60 +/- h.p. hmmmm

Racing Geek · 03-06-2012, 11:50 PM

Quote:

Originally Posted by Crom_child

Let's see an XS under 400 lbs. w/ 60 +/- h.p. hmmmm

You mean a stripped down xs650?

Crom_child · 03-07-2012, 07:18 AM

...a late Maxim DOHC mega-sized 500cc engine swapped into a 77-78 XS400 frame.
The pic below is a stock 82-83 XS400 dohc.
.

The following is directly related to this thread: engine upgrades ...

Per Yamaha specs a stock 38 hp '77-78 xs400 model = 186 kg. / 409 lbs.
Tossing the stock fenders / seat / pod etc. a cafe'd xs400 could weigh less
- say around 280-285 lbs.?

The 1982 XS400-R DOHC engine produces "45 hp / 9,500 rpm"
Given its advanced architecture it's likely a dohc xs400 motor makes
an actual 49-50 hp in top tune (+ low miles).

Option 1: GS based 510cc
Depending on carbs / cam / exhaust a modded XS400 dohc engine, taken to 510cc,
may be able to produce 60 hp @ 9,500 rpm. although this goal requires a flowed cyl. head.
I'm thinking of a mega engine being equipped w/ Yoshimura DOHC cams.

Option 2: less is more ... 440cc
A DOHC XS400 engine can be over bored using Kawa gpz1100 pistons > gives 440cc.
Engine remains fairly stock; one may be able to keep the original cyl. liners.
Should make 49.5-50 h.p. using stock components, big exhaust.
Yoshimura used to make piston kits & cams.

Option 3: 440cc + Flat slide carbs
Adds estimated 4-5 hp. .... for 54 h.p. total.

Garlic_Sauce · 03-07-2012, 12:53 PM

I wonder what mine weighs, I need to get her on a scale. I know the stock mufflers and center stand had to make a huge dent.

MotoRolla · 03-07-2012, 01:55 PM

since we started on my build i'm sure my bike lost at least 40 pounds.

Sinister Imaging · 03-07-2012, 03:10 PM

Hmmm wonder what mine weights?

Racing Geek · 03-07-2012, 04:19 PM

Before I started changing everything with the motor swap my 360 was on track to be real close to 300 pounds wet. I would imagine your xs400 could be close to that.

The gs750 should be able to get under 400 pounds wet. You seem to be using a lot of steel in your build so my guess is you'll be around 430-450 wet.

03-06-2012, 01:49 PM	#151
Crom_child Dux Brittania Fighter Local Time: 01:59 AM Location: SW Hinterlands Posts: 142 Flip Offs: 0 Flipped Off 0 Times in 0 Posts	Re: 1978 XS400 CAFE Build Real nice work... clean bike XS400 DOHC motor being bored to accept GS500 liners & pistons ... Left is GS500 piston 1 mm o/s, right is XS400 dohc stock piston @ 69mm. "Never apologize, its a sign of weakness" John Wayne and Jethro Gibbs

03-06-2012, 03:12 PM	#152
Garlic_Sauce RUST REMOVER CF Addict Local Time: 04:59 AM Location: CT Posts: 1,064 Flip Offs: 5 Flipped Off 3 Times in 3 Posts	Re: 1978 XS400 CAFE Build Thanks. ^^^^^Nice dude, keep me posted on how it turns out. "Oh my god look at this, it's a machine! You know, your like looking into the mechanism of the universe..." -Indian Larry- Current build, check it out. xs650 Brat Tracker:http://www.customfighters.com/forums...ad.php?t=57958 78 XS400 CAFE build (SOLD): http://www.customfighters.com/forums...ad.php?t=53414

03-06-2012, 04:09 PM	#153
Sinister Imaging personal hazard CF Addict Local Time: 04:59 AM Location: Far Westend (Henrico), VA Posts: 1,277 Flip Offs: 5 Flipped Off 8 Times in 7 Posts	Re: 1978 XS400 CAFE Build I want to do a big bore on mine too!!!!!

03-06-2012, 10:41 PM	#154
Crom_child Dux Brittania Fighter Local Time: 01:59 AM Location: SW Hinterlands Posts: 142 Flip Offs: 0 Flipped Off 0 Times in 0 Posts	Re: 1978 XS400 CAFE Build Dunno who owns the whole hog DOHC XS400/GS500 hybrid motor. Hell of an upgrade... Saw the machining pics on Photobucket. Let's see an XS under 400 lbs. w/ 60 +/- h.p. hmmmm "Never apologize, its a sign of weakness" John Wayne and Jethro Gibbs

03-07-2012, 07:18 AM	#156
Crom_child Dux Brittania Fighter Local Time: 01:59 AM Location: SW Hinterlands Posts: 142 Flip Offs: 0 Flipped Off 0 Times in 0 Posts	Re: 1978 XS400 CAFE Build ...a late Maxim DOHC mega-sized 500cc engine swapped into a 77-78 XS400 frame. The pic below is a stock 82-83 XS400 dohc. . The following is directly related to this thread: engine upgrades ... Per Yamaha specs a stock 38 hp '77-78 xs400 model = 186 kg. / 409 lbs. Tossing the stock fenders / seat / pod etc. a cafe'd xs400 could weigh less - say around 280-285 lbs.? The 1982 XS400-R DOHC engine produces "45 hp / 9,500 rpm" Given its advanced architecture it's likely a dohc xs400 motor makes an actual 49-50 hp in top tune (+ low miles). Option 1: GS based 510cc Depending on carbs / cam / exhaust a modded XS400 dohc engine, taken to 510cc, may be able to produce 60 hp @ 9,500 rpm. although this goal requires a flowed cyl. head. I'm thinking of a mega engine being equipped w/ Yoshimura DOHC cams. Option 2: less is more ... 440cc A DOHC XS400 engine can be over bored using Kawa gpz1100 pistons > gives 440cc. Engine remains fairly stock; one may be able to keep the original cyl. liners. Should make 49.5-50 h.p. using stock components, big exhaust. Yoshimura used to make piston kits & cams. Option 3: 440cc + Flat slide carbs Adds estimated 4-5 hp. .... for 54 h.p. total. "Never apologize, its a sign of weakness" John Wayne and Jethro Gibbs

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03-07-2012, 12:53 PM	#157
Garlic_Sauce RUST REMOVER CF Addict Local Time: 04:59 AM Location: CT Posts: 1,064 Flip Offs: 5 Flipped Off 3 Times in 3 Posts	Re: 1978 XS400 CAFE Build I wonder what mine weighs, I need to get her on a scale. I know the stock mufflers and center stand had to make a huge dent. "Oh my god look at this, it's a machine! You know, your like looking into the mechanism of the universe..." -Indian Larry- Current build, check it out. xs650 Brat Tracker:http://www.customfighters.com/forums...ad.php?t=57958 78 XS400 CAFE build (SOLD): http://www.customfighters.com/forums...ad.php?t=53414

03-07-2012, 01:55 PM	#158
MotoRolla motorbikes'n'rollerskates Fighter Local Time: 01:59 AM Location: Vancouver, BC Posts: 170 Flip Offs: 2 Flipped Off 2 Times in 2 Posts	Re: 1978 XS400 CAFE Build since we started on my build i'm sure my bike lost at least 40 pounds. It's always better on wheels. foxtrot uniform charlie kilo tango hotel alpha tango sierra hotel india tango!

03-07-2012, 03:10 PM	#159
Sinister Imaging personal hazard CF Addict Local Time: 04:59 AM Location: Far Westend (Henrico), VA Posts: 1,277 Flip Offs: 5 Flipped Off 8 Times in 7 Posts	Re: 1978 XS400 CAFE Build Hmmm wonder what mine weights?

03-07-2012, 04:19 PM	#160
Racing Geek lb/hp is what it's about! Local Time: 03:59 AM Location: Milwaukee, WI Posts: 8,770 Flip Offs: 146 Flipped Off 63 Times in 54 Posts	Re: 1978 XS400 CAFE Build Before I started changing everything with the motor swap my 360 was on track to be real close to 300 pounds wet. I would imagine your xs400 could be close to that. The gs750 should be able to get under 400 pounds wet. You seem to be using a lot of steel in your build so my guess is you'll be around 430-450 wet. Build-off project: GSXR conglomeration (don't post in this one) Build-off discussion: GSXR conglomeration Old project: CL360 (traded away)

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