saxon 301 running issues

[Warner20]

I'm going to try and explain the issue I am having with my 94 Saxon 301, I'm on my fourth 12 hour night shift and have had a poorly toddler to go home to the last few days so my brain is a bit fried but please bare with me!

So after rectifying the issues I had with the charging system I thought I was good to go and start using the 301 for my daily commute (60 mile round trip) for the first few days I had no issues whatsoever and it ran like a dream. Then one morning on my way in it started coughing and spluttering loosing power and then picking up again almost like there was a fuel blockage or something along those lines so I decided to ditch into the nearest train station and come back to it at the end of my day. To my surprise when I picked it up that evening it started and ran like nothing had happened so probably naively on my part I decided to carry on using it, again it was fine for the next few days until the symptoms returned on my trip home one evening, luckily I managed to limp the 30 miles back home where as I literally pulled into my driveway it backfired and came to a spluttering halt! it does still start and runs cleanly when on the center stand but as soon as I try to ride it down the street and put it under any load the symptoms almost instantly return.

In the coming days I stripped the carb where no issue could be found, set float height, checked needle clip setting, drained the tank, installed an inline fuel filter, set the timing, went over electrical connections to ensure they were tight and clean, changed plug ensuring the gap was correct, checked air filter for cleanliness and probably a few other things I cant think of right now.

So my question to you knowledgeable lot is... can you think of anything else I should be checking/changing?

I should note at some point this bike has been fitted with an aftermarket ignition setup which uses and optical pickup but seeing as the issue only occurs under load I don't think this would be the problem?

A friend is lending me a new coil tomorrow to test out so will report back on the findings with that but any pointers you can give me in the interim will be much appreciated!

Cheers in advance!

[DAVID THOMPSON]

tired wires some thing electrical as that been the big problem here in the cars and bikes

my 2002 rt125 has 23,000 on it it suffers from a tired wiring harness
almost every spade lug has been replaced or re-soldered to the harness
its 16 years old
new harness is needed but it will have to wait a bit till i build one

dave

[Blurredman]

Any way you could change the electrical system too? Normally when they blow, they die completely instantaniously, but older systems might try to hang on before dying completely?

[Puffs]

Warner, sorry to hear your running issues have come back.

So I understand it runs fine, and then all of a sudden it goes into a mode of coughing and spluttering, loosing power, and then a bit later it picks up again & runs normal. Or when you park it when still in the uncooperative mode, and you pick it up later, it's fine again. For a while at least.

To me that sounds like an ignition problem, not a carburettor or fuel supply problem. It could be a spark plug issue, but usually that doesn't go away without doing anything.

A loose contact, or an intermittent contact with earth, as could both be caused by tired wiring, is also possible, but that usually means it has 2 modes: running fine & not running at all.

The intermittent coughing and spluttering you can get if the contact breakers make poor/ poorly timed contact (contamination), if the capacitor/condenser leaks, or indeed with a faulty coil. But I now understand you don't have a conventional ignition, but instead something with an optical sensor (or is it a Hall sensor?), and doubtlessly some other modern circuitry. I have no experience with those. Nevertheless, I suspect that's where the problem is. Or indeed the coil, so please let us know what comes from the test with your friend's coil.

I once had a KLX650A that did same, 2 modes: fine, or coughing & spluttering. I couldn't find it, because it went away whenever I wanted to diagnose it. And then it died completely. Put another (borrowed) CDI, but that didn't help. Put another coil (from a Kreidler...) and it ran fine! So I replaced the coil with a proper one, but with a multimeter I could not find any difference between the 2.

[Warner20]

We are GO!!!

Changing the coil had no effect on the issues I've been having so that only really left the aftermarket ignition that had been fiitted in the past as I've had the carb off countless times now and im confident its set up perfectly!
So i managed to get hold of a set of points from my friend and revert back to those. The timing proved quiet tricky to get 'just right' as it seemed just about every setting we tried which were sure was correct reulted in the engine running backwards!

Anyay we got there in the end and now she runs beautifully!

I did find that when the previous owner had fitted the optical pickup they had used the old cable which ran from the condenser to the coil but had extended it with a bullet connector and then somehow got it back inside the black tubing with the rest of the loom which was why I'd previously misssed it whilst looking for loose connections, low and behold this connection wasnt very good at all so im confident that was the issue so i will now probably rebuild the entire setup with all new wiring and soldered joints and re-fit it at some point and see how it goes as there is a definite drop in power since going back to the standard points set-up.

Thanks for the replies guys!

[DAVID THOMPSON]

please note that bullet connector starts with B and a C as also do the words BAD CONNECTION

if its not soldered its usually a BC

i never crimp a spade lug it is always soldered on the wire

dave