Guys I'm still really struggling to get this quad going, I have posted a video on YouTube of what it's actually doing it would be great if some one could take a look and help me out, pretty sure I'm just over looking some thing simple

Video link


Thanks rich

 

well...you're showing us that the machine cranks over...but do you have spark at the spark plug? Ground the electrode and crank it over...you should see a decent spark arcing to ground. If you don't then you need to check each component from stator to ignition to see what's faulty.


If you have spark, then you need to shoot about 3 full seconds worth of starting fluid down the spark plug hole, replace spark plug, then turn it over.


If it fires then you have a fuel deliver issue (carb/valves)


If it doesn't fire with good spark & starting fluid then you'll need to confirm compression/timing

 

Thanks for the reply @dirtdevil101. Sorry I didn't post too much detail in my first post let me just go over a few things I've done.

Quad was running fine then cut out and wouldn't start, I narrowed it down to no spark, after ruling everything else out I replaced the stator magneto and sorted the sparking issue out but bike would still not start.

I disconnected all none essential electrics to rule out faulty looms and kill switches to no effect.

I checked compression and was getting only 50PSI installed new piston kit and replaced gaskets, compression now at 145psi and still no start

After installing new piston I made sure I set all the timing correctly

Stripped carb down and cleaned it out, reset to manufacturers spec

Also tried spraying easy start directly into air intake and nothing!

I have tried everything yet nothing seems to work, I have spark, compression, fuel......

Thanks for taking the time trying to help me, thanks

 

Don't shoot the ether into the intake stream...shoot down the plug hole & report back.


If you have spark/ether (in the combustion chamber via the plug hole)/compression it will run...if it doesn't then I'd be suspicious of the timing...you may be getting spark but in needs to be at TDC...if off enough it wont ignite the compressed mixture...


good luck...

 

That was my thought, you have fuel, compression is there so valve timing must be good. You have spark, but is there a way to set the spark timing?

Modern systems have the CDI controlling timing, but never know on one of these. I've only worked on one Chinese atv so far.

Another thought is maybe a bad plug or the spark is weak? Sometimes you can get spark when checking, but the plug won't/can't fire under compression. What color is the spark?

I've not had a problem using ether in the intake, if I'm slow putting the plug back in, ether evaporates pretty quick. It can be better to spray as the starter is cranked, so it pulls the ether in. Open the throttle too, choke open, it's going to be a rich mixture.

 

I shoot it down the plug hole to eliminate valve/reed issues...the combustion chamber needs fuel/air, spark (at the right time) and sufficient compression to ignite the mixture...once I hear it run in it's simplest form I can move on to other possible issues...I'm a pretty simple guy and like to break my problem solving down into the simplest elements...it's just a formula that's worked for me over the years...

 

Yes Dirt Devil you're right, my first attempt is just to see if it will fire up through the intake. One of my best race cars had Dirt Devil on the trunk lid, and a Taz on the hood.

Makes me think... Using the plug hole might be a good idea in this case. Have seen some cases where the cylinder has good compression, but the intake valve isn't opening. Won't always happen that way, because air to make compression has to come from somewhere, but I have seen it happen.

The head/cylinder looks very similar to the one I worked on last week, a Yamoto, but your side cover is different. It should have a valve adjustment access cap where you can watch to to see if the intake valve is opening. I hear a thump in the exhaust, but it might not hurt to watch the exhaust valve also.

 

Thanks for the replies guys, interesting reading! I have tried spraying easi start directly in to the spark plug hole which doesn't make a difference intact I even got a syringe and squirted a little petrol in there to see if that helped but still it would not start.

Reading your replies is making me question the timing like @collar bones mentioned it does have a Cdi unit, could this be faulty, perhaps telling my the spark to fire at the wrong time?

Also after putting the new piston kit in obviously I had to set the timing right, which I checked online on where it should be, all the guides and videos I watched suggested there should be a mark on the flywheel which indicates tdc on mine there are two marks, both the same and about a centimetre apart it's like a stick with a circle above it, I wasn't sure which marker to go with so I went with the first one that came into view when turning the flywheel anti-clockwise???

Could it really be as simple as the timing been off by about 10mm?

Should I try and reset the timing usually my the other marker?

And again thanks for the help guys really appreciate it

Rich

 

Spark looks blue/white and strong

 

10mm can translate into being off quite a bit.

Maybe pull the plug, insert a drinking straw into the cylinder, then manually turn the crank and bring it to TDC, feeling for the top with the straw. Then see if the mark you used is aligned.

Do you have the link to the timing so we can look at it?