Hi All,

I'm looking for some advice on the two subjects mentioned both on my very old bike.

1. Starting Issues:
The bike does not like to start on the electronic ignition atall even to the point where the battery drains itself, I tried jumping it off my car (not runnnig at the time) and still it would not start off the ignition. It kickstarts almost first attempt (most of the time).

I have checked the voltage coming back to the battery when its running (as per manual) and its giving me roughly 14Volts at 2000revs which I think is normal.

when its running it ticks over and sounds ok this combined with the correct voltage coming back to the battery makes me think that the rest of ignition system is ok.

2. Running Issues:
As above it runs fine (usually) but when i'm doing motorway speeds (70) for any length of time I lose power and the revs die off a bit and the speed drops off usually down to about 40ish.

when I pull into the hard shoulder it wants to stall (and if it does its a bugger to get started). if it doesn't stall it will go back to normal in ten minutes or so, I think its carb icing but thats just a guess.

Any advice is welcome

Cheers
Ronson1000

This sounds like the generator part of the ignition is overheating during use. Has it got the Boyer-Bransden electrobic ignition conversion? Friend had this problem with his XS650, had to go to the manufacturers to sort the problem.

Sounds like it's charging ok from your figures, when did it last get a set of plugs and the valve clearances checked? It's also worth checking the HT leads are secure in the coils and the plug caps, and sometimes it's necessary to trim about 1/4" off the ends of the leads and then refit them into the coils and caps - the wire in the ends gets corroded and makes high resistance joints, a bit of fresh metal to screw into is all that's needed.

The motorway problem does sound like classic carb icing. Dunno what the weather's like up your way but damp air and temps in low single figures are the best (worst) conditions for it to occur. Might be worth bunging some of that Pro FST additive stuff in the tank.



A rare old beast that

That generator over heating thing sounds nasty hope it's not that

I have checked all the usual things like ht leads and so on, I think I'm going to change the whole ignition system over the winter to try to fix it

silkolene fst pro is on it's way from eBay at the moment I will see if that fixes the suspected carb issue, hopefully. I also forgot to mention that I'm running k&n filters directly into the carbs I might put the original airbox back on to see if that helps.

Now thats a nice looking bike.

I wonder about the battery; on the starter motor, that might be drawing more energy than the battery can provide for that AND a decent spark????

On the motorway speeds, I like the carb icing too. But also check you have a clear vent into your petrol tank. If this is partly blocked, you can get a partial vacuum in the tank that can end up starving the carbs (had this on my 750 Bonnie)

I put some K&N pod filters on an old GSX1100 I had. Didn't set them up of course, just bolted them on. On cold damp mornings it would putter out and I could scrape the ice out of the pleats

I had this exact problem years ago, it tested ok when it had been started up and just warmed up and then tested but out on the road when it giot really hot it stopped producing enough power. Had the generator rewound and it was fine after that.

Must admit I hadn't thought about carb icing! Specially with K&Ns on it.

Hi all,
Update time, I bought silkolene FST pro and it has worked treat had it basting down the m8 (local motorway) no probs.

Still wont start on electronic ignition but i've ignored that problem and I jjust kick start it now.

Another small issue I was wondering if anyone had an answer to:
the bike idles perfectly cold or warm (about 1500rpm), but sometimes it seems to 'stick' at about 4000rpm usually coming up to traffic lights an that sort of thing. The upshot is I adjust the idle screw to bring it down to a normal level all seems good I ride off happy next set of lights it fecking stalls and its a bugger to kickstart whilst your holding up loads of traffic and it doesn't look very cool.

Oh and does any one know if that ACF50 spary is any good?

Cheers all.

Not sure about the sticking tickover, but ACF50 (or the ScottOiler FSH(?)365) IS good. Just don't get it on anything like tyres or brakes!

Yeah i read the online manual it says at least 6 times in three paragraphs not to go any where near the brakes. So I figure thats important.

I'm wally that will forget and just spray everywhere then go straight on at the first roundabout.

sticking tickover might be the throttle cable or linkages needing lubrication, (ie not always shutting off properly) or a carb problem.

My Kwak starts doing this in winter and usually just needs some WD40 on the throttle linkage (which on mine is between the middle carbs and awkward to get at).

Yep - sounds like your throttle is only attached on one cable. Some are designed like this, and others have both an open and a close cable. Have a wee look to see if you should have two cables. if so, you'll have a knackered cable. More likely you're only supposed to have a single cable and it's sticking. Hose some WD40 down the cable, and check that the pivot points in the carburettors are moving easily ehough (lube them too). They should spring shut, so it might be worth checking those springs too.