Over the last fortnight I have posted the problems I have been having with my GS.  Well just when I thought I was rid of the little bastard gremlin it came back again but this timed stayed around.

A quick summary of the events:
1. Whilst returning from a ride the GS started to missfire on the right hand cylinder.  After limping home she came good just metres from the driveway.  Attempts to get the miss to come back failed so I cleaned the contacts (one had some corrosion) and hoped for the best.
2. Last Tuesday whilst taking the bike over to my local mechanic for a service, the miss came back.  Left the bike with him, again the miss didn't want to come back and after going over the electrics testing everthing - it looked some some other cause.  He did find a leak in the fuel petcock diaphram and some gunk in the carbs - cleaned the carbs and installed a new fuel petcock.  Ran the bike for ages and took it for a ride - she ran sweet with no problems.

So on Saturday I went over to pick the bike up.  When we got there he started the bike to show her ticking away nicely - all looked good.  I put my riding kit on, started the bike --- wtf she was missing and the right hand cyclinder wasn't firing.  There was no spark getting the the cylinder at all.  This time the fault stayed and didn't go away (thankfully), so working through the electrics we found that the pickup sensor had a resistance reading over +4000 ohms!  Voila, this was the source of the problem .  A replacement one is now on order.  As a matter of interest I let the pickup sensor cool down, the resistance dropped to about 420ohms, then I heated it up with a soldering iron on the contacts and the resistance rose dramtically.

So in the end at least we found another problem that may haved caused some frustration down the track (leaking diaphram), installed a neat fuel filter, cleaned the carbs, and the found the cause of the missfire.  For any riders in Brisbane Australia, John @ Wynnum Motorcycle Repairs is one of the 'old school' mechanics, he works to do the job right and isn't focused on pushing as many bikes through his shop in day as he can.  In the end you only pay the same or less than some of the larger dealer service shops too (my last experince with a major shop wasn't that good).

Cheers
Conrad

at least you got some future needs taken care of, and on the right track now

Ha ha your avatar seems somehow appropriate for the 'leaking diaphram' that was found  

Yeah, that leak would have driven me mad in a month or so, the plan is to rejet with a new exhaust and pod filters.

One thing John(mechanic) did was install the fuel filter BELOW the carbs.  This way you can easily see if there is water in the fuel system as the filter is now the lowest point in it hence the water will colect here 1st, pretty handy when in remote areas where fuel supplies are a bit dubious     Also this keeps the filter well away from the engine and as it's clear you can easily look at it to check for dirt etc.

Cheers
Conrad

excellent, btw, what filter did you use?

I will have to have a look at it a bit closer tonight, he said it was actaually a servicabe filter you can flush and re-use, pretty small and transparent as well.

Cheers
Conrad

btw, the avatar was courtessy of ragging on the gstwin gods  :mrgreen:  :dunno: (along with the title)

Quote from: conradvr[...] we found that the pickup sensor had a resistance reading over +4000 ohms!  Voila, this was the source of the problem [...]

Aha!  I thought so.  Unfortunately, the resistance readings checklist I wrote up in another thread wouldn't have done you much good unless you measured when the bike was warmed up and exhibiting the no-spark symptoms.

That's why gremlin is a good word for electrical problems like this!

Gremlins eh? 1940's pilot talk. still, guess its better the the little leprecons with metal shoes tap dancing beneith the valve covers

You got that right, this little gremlin was particulary good at picking when to play up, but in the end we nailed it  :guns:   Or maybe it wanted us to find the little leak in the diaphram first  not enough bike for two gremlins I guess.

yamahonkawazuki, sorry I forgot to take a look at the filter, will try again tonight


Conrad

Quote from: Kerry

Quote from: conradvr[...] we found that the pickup sensor had a resistance reading over +4000 ohms!  Voila, this was the source of the problem [...]

Aha!  I thought so.  Unfortunately, the resistance readings checklist I wrote up in another thread wouldn't have done you much good unless you measured when the bike was warmed up and exhibiting the no-spark symptoms.

That's why gremlin is a good word for electrical problems like this!

Well just to close this thread.  

Finally after some searching we found a ignition pick-up plate and sensors at a bike wreckers and they arrived last night.  So this morning (I had to attend a 'business' dinner last night) I quickly removed one of the sensors and soldered it to the existing wires (plate is modified to advance the timing 5 degrees).  Screwed all the bits down, checked that nothing would hit each other than fired up the bike ---- ooohhh to have two cyclinders firing makes such such a large difference     And I have a spare sensor and plate for the future.

So many thanks to all that offered help and especially those listers that were willing to ship me a sensor from the States to help me out.  Its now time to go riding.

Cheers
Conrad