81 gs 450 no power to coils

[mrameswmartin]

i just acquired a 81 gs 450 . originaly i was told the ignition was bad . however i jerry rigged it last night with one from a honda.. i have power now but i have to jump the starter and no power to coils... any ideas?

[bonanzadave]

Cliff has a 450 wire diagram...

http://members.dslextreme.com/users/storagecliff1/images/wiring/GS450GA_wiring.jpg

Could be the ignition switch.

[pete]

Firstly, welcome to the forum and good to see another twin coming back to life.

Also check for a clutch and/or side stand switch as some models have one or both of those which need to be on before it will start. I believe they should be in line with the kill switch.

BassCliff should be along to welcome you at some point, but in the meantime here's his page where you can get both the Clymer and Haynes manuals (Clymer is better IMO):

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

[pete]

Oh, also, the Honda ignitor most likely won't work as from what I've found so far the 450's are quite unique, but there are tests in the manuals to see if your ignitor is good or bad.

[mrameswmartin]

Ok so leads,grounds and fuse good.. I replaced the ignition switch with one of honda( was able to match wires with the help of both wiring diagrams ) . I still have no power to coil or the starter button. No lights come on the control panel either. I have power after the main fuse tho... I don't understand what I'm missing. Is the honda ignition not compatable? Also in the wiring diagram there was a "starter disconnect switch" coming from the starter relay to the starter switch. I couldn't find it.

[pete]

It has to be either a bad ground or a bad connection I would say.

Unless of course you have the dreaded clutch or sidestand switch which will give you another point of failure.

The starter disconnect switch could be the clutch/sidestand switch or it could be the kill switch, can't remember what they call them on the diagram off the top of my head.

[mrameswmartin]

What is the "dreaded clutch " or "sidestand switch"? Is there a way to bypass thos oe the kill switch? Just temporarily to locate the problem area?

[mrameswmartin]

Ok im almost positive that is in my head light bucket and its already bypassed. after no luck finding the"switch" I traced the wire (y/gr from the starter relay) all the way to the starter button harness. On the way I found it was poorly spliced together (this is where I know believe it is bypassed) so I cleaned it up a little and put a connecter on it. Also when I turn the key on (keep in mind this is the one off a honda I jerry rigged . So it may not be compatible or broke. I am going to get a new one after work) no indicator lights come on nor do I have power at the headlight.

[mrameswmartin]

Well I worked on the bike till about 2 last night , but now I have a new issue.
I got a new ignition and fixed the power issue( pete was 100% correct about the honda switch not matching up). Its got good spark but won't fire even with carbs open and ether. After tinkering for a bit I tried it again and she backfired through the carbs. Took the points cover off and matched "TDC" mark with left cylinder and it seemed to be off just a wee bit. The reference mark sits above the "T" instead of the line directly beside it. So I took the valve cover off but it all looks good as far as the lobes are concerned. The timing chain was tight but I adjusted that prior to removing the valve cover .there are 2 key ways on the end of the cams that I assume are for reference for correct timing, is that right? this its my first suzuki so I'm in between lost and possible alcohol induced coma.

[mrameswmartin]

would that have anything to do with back firing through the carbs?

[pete]

First of all, get yourself the Clymer manual off BassCliff's site (hopefully you get a mega welcome from him somewhere along the line).

In there you'll find all the timing info you need to make sure everything is spot on.

Basically, there are some arrows on the camshaft sprockets that need to line up a certain way. The ones on the exhaust camshaft (front of engine) need to be located relevant to the valve cover sealing edge (if that makes sense). The one on the inlet camshaft (rear of engine) needs to be lined up with a certain number of links of the cam chain from the front camshaft.

That will get your valve timing done, and then the ignition timing is all done with the signal generator plate on the right side of the engine, and again it's all outlined in the Clymer manual.

There's two recent things I've seen involving backfiring through the carbs.

One was Flaming Chainsaws bike when a dodgy ignitor was on there that was firing sparks at weird intervals.

The other was my bike when I started it for the first time after the engine rebuild. I had a rag over the carb intakes that was far far far too restrictive and caused it to run far too rich and it also backfired through the carbs a couple of times.

Hope that helps...