Project GSXR 400

[aceofhearts]

Here is my new project bike!

Its an early 90's Suzuki GSXR 400, which has been off the road for a while and is currently in several pieces. So far from a quick look around i can see it needs a new oil cooler, brake pads, chain, spark plugs and wiring bits. It also needs the exhaust and airbox refitting and to get it running, and also raising the front back up as the forks are currently very low in the clamps.

I will start stripping it down and investigating this week

All advice and ideas welcome

https://thumbsnap.com/s/7Hg3i6iZ.jpg

https://thumbsnap.com/s/Cny2ccIz.jpg

https://thumbsnap.com/s/TUyJus47.jpg

https://thumbsnap.com/s/H8hDp9Sn.jpg

[aceofhearts]

Had my first quick look around the bike yesterday and spotted a few issues, mainly around the loom and wiring (most of it is not connected)

Does anyone have a wiring diagram for the bike at all? I have not had much luck looking for workshop manuals

I will get cracking on with it more next week when i can sort out a space in the outbuilding

[Nope.]

Wiring Diagram for the 76A:

https://www.graniterock.co.uk/400manuals/GSX-R400_GK76A_Wiring_Diagram.pdf

Spec sheet:

https://www.graniterock.co.uk/400manuals/GSX-R400_GK76A_Spec_sheet.pdf

Other Manuals:

https://www.graniterock.co.uk/400manuals/

You need to join 400gb forums, theres a wealth of information on most 400 grey imports.

So what are you plans, full strip and rebuild including motor? Or just a general tidy up?

Don't forget to change the carb seals!
____________________
Former: Derbi GP1 50, Sachs XTC 125, Suzuki GSXR 400 GK73A, Kawasaki ZX7R, Suzuki DR250, Yamaha RD350
Current: 2011 Yamaha XT660Z Ténéré, 2003 Yamaha YZR-R1 5PW (In Build), 2009 Kawasaki ZZR1400

[aceofhearts]

Thanks, thats a great help

I will join the forums now and have a read through. Plans are to hopefully get the engine running and if all is well do a strip / rebuild to get the bike up to scratch.

I have also had a look on the net but are there any generally recommended parts suppliers?

I also see the Sachs in your signature, got any pics? That was my first 125 so have a bit of a soft spot

[haroman666]

I have some 76A cams for sale if you by any chance want them.
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The mistresses: 2000 Honda CBR600f, 2000 Honda VTR1000

[Nope.]

[aceofhearts]

[Nope.]

[aceofhearts]

Made some progress today and started to clear out the outbuilding and managed to get the bike in. Also pulled off the bodywork to have a look at the mess i had to work with.

https://thumbsnap.com/s/PBUNuogd.jpg

https://thumbsnap.com/s/6qTQzoW4.jpg

Mess of wiring under seat (lots of plugs with nowhere obvious to go)

https://thumbsnap.com/s/net2ksXM.jpg

And the top of the engine (coils loose and no spark plugs)

https://thumbsnap.com/s/7Qv43ROg.jpg

[aceofhearts]

Today has been quite productive, have pulled the loom from the bike to work out where all of the wires are supposed to go, and since there seems to be only a Japanese wiring diagram available I have been chasing all the wires through and translating it into English to try and help others that may be in the same position. There are a few bits i am still unsure on, but think it has turned out quite well

I also pulled the subframe off once the loom was free to make a bit of extra room.

Next up is to retape the old loom and tomorrow hopefully get it back in.

https://thumbsnap.com/s/711AvOpg.jpg

https://thumbsnap.com/s/qU9IawPB.jpg

https://thumbsnap.com/s/aHmTF0u8.jpg

https://thumbsnap.com/s/1fCQO5W6.jpg

My tidied up and translated wiring diagram

https://thumbsnap.com/s/nijXDcQI.jpg

If anybody can help me with the unknown components in the diagram (Computid?) I would be very appreciative of some help (I can email over the full size document)

[aceofhearts]

Loom fully labelled and tidied up

https://thumbsnap.com/s/AFnFVOXD.jpg

[aceofhearts]

Progress today:

After plugging back in the loom and hooking up a battery, all of the gauges, warning lights and headlights worked on the bike, so that is a step forward

I couldn't however get the bike to turn over on the button, but by shorting out the starter relay it turned over lovely which fills me with much more confidence

Next stop is finding out what these unknown plugs are on the loom, getting the carbs cleaned out, refitting the exhaust and try to get it to run.

Anybody with a GK76a able to look at their bike and tell me what these connectors are plugged into on their bikes? It seems my project bike has a few components missing

https://thumbsnap.com/s/opgtzXkb.jpg

https://thumbsnap.com/s/doDBwB0L.jpg

https://thumbsnap.com/s/fvUBwvue.jpg

[Nope.]

[aceofhearts]

Thanks i will email you one over when I get to work later

One of them has something to do with the indicators (maybe for an alarm?) and one has something to do with the generator. The last one i have no idea but i can get more info later when at work, so i can be a bit more helpful.

All are around the rear of the bike (CDI / fusebox area) but the loom has been mucked about with in the past so may be wrong.

[aceofhearts]

Ok have had a look at the diagram.

First Picture:
On the wiring diagram is next to the generator. Possibly a crank sensor or for the tacho?

Second Picture
Top right of the wiring diagram. Is connected to the indicators so maybe for an alarm?

Third Picture
Between the TPS and OIl pressure switch on the wiring diagram. Looks like a coil or something but cannot figure what it is? Judging by the area on the diagram maybe it plugs to something on the engine?

Whats your email address I will send you over the diagram?

[aceofhearts]

Ok i have a development from 400gb

The green connector is possibly for a side stand switch, and might be what is holding off the starter?

On the diagram a few posts above it is on the top right marked up 'Hazard?'

(It was marked hazard as for some reason it was connected to the indicators, but i can now see that they are just sharing an earth )

ETA

Kick stand switch it is (looking at ebay). I have now ordered one up as the bike currently doesnt have one (hence the paddock stand)

1 down 2 to go

[TotalGSXR]

[aceofhearts]

[aceofhearts]

Here are the wiring diagram pictures for plugs 1 and 3

https://thumbsnap.com/s/LMHChtp5.jpg

https://thumbsnap.com/s/47ymd0zD.jpg

[orac]

[orac]

[aceofhearts]

I have had a look on the bike and the other two connectors are definately not there, but now i am pretty happy that the first is the signal generator (i will be pulling off the covers tomorrow to find out where it should be) and the second may be for an airbox sensor, although my airbox doesn't have any sensors on it

[orac]

i have just had a look in my manual and found something that look like the second unknown thing on the wiring diagram - it labelled as a a solenoid. i on mine its for operating the variable valve timing.

following the granny image you have provided for the wiring i can just about see that 1 wire goes back to the CDI from this device. did they ever produce a v-valve motor for the GSXR range?
____________________
Current rides - 2016 Triumph Street Triple Rx, 1994 Suzuki Bandit 400 VM, TGB 204 Classic 125cc
"with nothing left to lose, there is everything to gain. It's not the size of the dog in the fight, it's the size of the fight in the dog"

[orac]

heres a scan of the wiring diagram for the 97 version of mine.
https://farm9.staticflickr.com/8492/8338867111_54a5b84aba_b.jpg
Wiring by f2268d215cc925918731918f4efa0289, on Flickr

i was just thinking as well, did suzuki play with those butterly valve in the exhaust to help inprove low down performane while still being ablle to keep the top end - think it was called something like exup, not sure tho, that may have been yamaha
____________________
Current rides - 2016 Triumph Street Triple Rx, 1994 Suzuki Bandit 400 VM, TGB 204 Classic 125cc
"with nothing left to lose, there is everything to gain. It's not the size of the dog in the fight, it's the size of the fight in the dog"

[orac]

it called SET - suzuki exhaust tuning, cant seem to find any thing about the 400 having it fitted tho.
____________________
Current rides - 2016 Triumph Street Triple Rx, 1994 Suzuki Bandit 400 VM, TGB 204 Classic 125cc
"with nothing left to lose, there is everything to gain. It's not the size of the dog in the fight, it's the size of the fight in the dog"