Non starter

[Mouse]

Hi

got a 1977 gs750 that's not been run for a good few years but dry stored.

Today armed with new filter, oil plugs, battery ect ect went to see if any life in it, short answer no,  no idiot lights nothing, put a spanner across starter solenoid and it will crank but there is no spark at any of the plugs, first port of call was the fuses but after half hour no fuses no fuse box nothing ???,

Any ideas where to start next

Thank you

   Mouse.

[wraith]

That's a good one 

Do you know if the bike was running before being stored?

First thing is there two red wires coming off the battery one thick going to the starter solenoid and one thinner which should be going to a fuse/fuse box? Just thinking has the fuse box/inline fuse been removed, the thinner red wire should come from battery to a fuse box then out of fuse box up to ignition switch then a orange comes out the starts supplying the rest of the bike, very very basically.

[Mouse]

yes bike was running and it was me that stored it.

pretty certain only one thick wire on positive side but at home now so cant check, dont even have manual anymore as fell in oil tub.

will go back tomorrow and see if i can find a thin red or orange wire.

Thank you

  Mouse

[wraith]

Looking in the manual you should have a big red wire going the starter relay, a thinner red wire going to a fuse box then a red wire coming out then going to reg/rec and the ignition switch. If this in not there or bust that could be why you have no power 

[BigT]

service manual

http://members.dslextreme.com/users/bikecliff/

[Mouse]

Hi

tried this

7 hours ago, BigT said:

http://members.dslextreme.com/users/bikecliff/

all I got was a page of what looks like a programming script ???

 

[BigT]

I tried the link just now and it works fine

Clear your browser?

[Mouse]

BigT

Tried it just now and it works fine now, thank you

And yep it shows a fuse box and even where it is, problem is still cant find it on my bike, o.k i admit i dont have the standed side-panels but i can't see any reason i would have hid the fusebox anywhere, but have been known to do stupider things,

Going back tomorrow with a big torch and a pair of specs,

[BigT]

Fusebox is under the left side cover, should have 4 fuses

[wraith]

Maybe you have big hungry mice and they have eaten it.

[R15UTT]

The positive /red wire goes down under the battery box where the other red wire is soldered to it . this often breaks as did mine on my GSX 11OO ET . This caused the reg/rec to burn out on mine . Well worth a look . Take the battery out & the battery carrier to get at it . Good luck . Colin .

[BigT]

just checked and your bike has only one fuse

[Mouse]

10 hours ago, wraith said:

Maybe you have big hungry mice and they have eaten it.

Har dr har har

[Mouse]

bear with me, my first ever attempt at posting photos on a forum.

o.k so went to lockup today and this is what I've got, positive (black) from battery to starter solenoid also black/yellow to same post which then joins to a red wire.

Black (with yellow sleve) to starter moter

yellow/green from starter solenoid to ?????

there is also a small metal box under the battery tray with a yellow wire and a black wire,  I think the yellow goes to the generator ??, (picture 2 with a pen pointing at it, what is it.

Is there any way i can bypass most of the original wiring, i only need to get the bike to start to check if the engine is o.k

Thanks, Mouse

[ral]

Looking at that lot I would be surprised if you have any current running through it, try removing and cleaning up all the connection points, if you’ve got a meter test each wire to see if there is any power or continuity getting through, bad earths will also stop you getting anything, again remove connections clean and refit.

looks like it’s been stood a while.

[wraith]

Not got a 750 manual with a separate reg/rec, but the one with 3 wires coming out is you reg, the other one is your rec, wires should be coming out of reg black going to earth, white/blue going to gen, yellow going to gen. Rec wires, red, white/red, going to switch gear, yellow to gen, white/blue to gen.

The black/yellow you have is a kwak earth? Sounds like someone has put a kwak  earth on as your positive  but it's going to a red so should be doing the job. The yellow/green goes to your starter button.

Like above, the first thing to do looking at what you have is start with disconnecting the wires and cleaning them up, as I bet they have a lot  of coronation on them.I

If need be you can put a combined reg/rec on.

Good luck I think you may need it 

 

[Mouse]

On 7/15/2019 at 8:47 PM, ral said:

looks like it’s been stood a while.

About 20 years give or take, but hopefully about to get a new lease of life .

yes it looks like a few hours sat there with a tin of servisol super 10, do i just spray it on the connectors and wait or do i have to abrade the connector as well, and if so what is the best way to clean inside the female connectors ??.

thank you.

[wraith]

Never used servisol super 10 always used some sand paper, as to the round female connectors, rap some sand paper around a screw driver and insert into the female (now that's some of this lot getting excited ) if it's one of the blocks connectors get a electrical flat head screw driver (small) there is a small tab inside that holds the terminals in place, (non wire side) you need to push them flat then you can pull each terminal out from the wire side and clean them up.

If you need any new connectors or wire, go to Vehicle Wiring Products. 0115 9305454 www.vehicleproducts.co.uk 

Well worth getting them to send you a order catalogue, but give your miss your bank card 

Before you ask  the bullet connector size are the 3.9mm ones 

[BigT]

What I'm not seeing is a ground from the electrical panel to the frame, or battery

The solenoid and the rectifier both need a ground to work

The yellow/green wire is the trigger wire from the starter button

You have a wiring diagram in the service manual, take a look at it

I find a Scotchbrite pad works wonders on the brass connectors. I use DeOxit on the female and gang connectors, do you have that over there?

As far as getting it to turn over, short the big terminals on the solenoid with a screwdriver

 

Edited July 18, 2019 by BigT

[Mouse]

6 hours ago, wraith said:

Never used servisol super 10

why is that please ???

 

6 hours ago, wraith said:

insert into the female

already got a account with vwp as got a landrover and there catalogue is compulsory.

BigT, there are earths, just not shown in photos, i have shorted across the starter solenoid and i can get the engine to spin over but there is no spark at the plugs, i assume that this is because i am bypassing everything but i have no idiot lights or any power anywhere.

 Unfortunately i do not have a service manual to refer to, the last one i had was a haynes one  but that no longer exists.

Thank you Mouse.

[wraith]

As in, I've never used it so don't know if you leave it on or not 

One way to check if/where you have power if you don't have a multimeter, is to remove your Side light contact one earth wire to it and one positive wire. Contact the earth to the earth on battery and touch the positive to each positive on the bike one by one, if power is there the bulb will light up.

It's quick and simple, the bulb ever lights up or it dose not  power on that wire or not no need to disconnect block connectors and you can see if power is getting from one side to the other.

Power wires red and or orange. Orange wires with tracers but these may be switch.

Edited July 18, 2019 by wraith

[ral]

23 hours ago, Mouse said:

About 20 years give or take, but hopefully about to get a new lease of life .

yes it looks like a few hours sat there with a tin of servisol super 10, do i just spray it on the connectors and wait or do i have to abrade the connector as well, and if so what is the best way to clean inside the female connectors ??.

thank you.

I use a soft wire brush to clean the male connectors, hold the connector in a pair of long nose pliers and scrub away any crud, scotch bright works as well, small round file to clean up female connector, or splash out on new connectors and replace all the old ones, you can reuse the small multi connector blocks and just replace all the male and female spades with new, strip the wires back to clean copper, you will be surprised how black and corroded it is at the old connectors.

Bit laborious but worth doing to freshen everything up, don’t forget to clean all the earths, check continuity with a meter once done.

Good Luck

[Mouse]

9 hours ago, wraith said:

Never used servisol super 10

I really need that  red faced emoji, i read it as never USE servisol super 10, doh

[wraith]

1 hour ago, Mouse said:

I really need that  red faced emoji, i read it as never USE servisol super 10, doh

They are there, look on the red bar at the top of the reply box 6th one from the left touch that and the emoji will come up then just touch the one you want 

[BigT]

On 7/18/2019 at 10:16 AM, Mouse said:

why is that please ???

 

already got a account with vwp as got a landrover and there catalogue is compulsory.

BigT, there are earths, just not shown in photos, i have shorted across the starter solenoid and i can get the engine to spin over but there is no spark at the plugs, i assume that this is because i am bypassing everything but i have no idiot lights or any power anywhere.

 Unfortunately i do not have a service manual to refer to, the last one i had was a haynes one  but that no longer exists.

Thank you Mouse.

I sent you the link to the factory service manual, see above