PVL ignition problems

[JohnnyO]

Hi Ji, i checked the timing with a dial guage and it is still set at 2.2mm BTDC.
Rossco does your PVL work properly when it dries out? How wet does it have to be before it plays up.. does riding in a muddy race cause problems?

[colmoody]

While we are on the subject of electronic ignitions can someone sell me on the virtues of same over and above points and condensor
relative to VMX bikes that came standard with points ignition.

[Rossvickicampbell]

JO - not very - wet muddy race was the culprit I think.  I have since mad up a little plastic box to cover it and haven't had a problem.  After practice it wouldn't start, didn't want to run etc.

Rossco

[Lozza]

Just a few small points(?) of clarification. If  the flywheel slips it would be retarding the ignition not advancing, the correct way of setting the flywheel onto the crank taper(Morse tapers are for the tailstock Ji ) is to use valve grinding paste to lap it on and get rid of the high spots.By just doing that and pressing on by hand you usualy need a puller to get it off the taper, no need for banging of tapping with anything.The lock nut is best secured with a rattle gun on the lowest torque setting.Woodruff keys are for ease of assembly at the factory and apprentice mechanics. To answer your question Col a good electronic ignition will not have a fixed curve, OK with a 4 banger where weights can be used to add advance with rpm, this won't work in a 2T engine.Add to this more voltage delivered to the plug an no need for constant attention makes the CDI the way to go.

[colmoody]

Lozza the delivering more spark to the plug, is that at all/any revs including starting.

[Nathan S]

Depends on the system Col, but in the case of original VMX-era CDIs, often the spark is relatively weak on kick-over, compared to points.

However, the opposite is true at high revs, when it really matters.

And don't under-estimate the value of the non-linear advance curve - its a huge part of the reason why modern bikes are so tractable and still go like buggery. Its easy to point at things like exhaust power valves, water cooling, and flat-slide carbies and say "That's where the difference is!" - and you'd be mostly right - but the humble ignition black-box is also a big factor, even compared to older electronic igntions.

[colmoody]

Reason on the plus side of the electronic ignitions seems to be a bit thin on the ground. Thanks for your replys Nathan and Lozza but I honestly thought I/we would be flooded with words of wisdom on this one.

[Lozza]

You were Col

[Nathan S]

You're a hard man to please Col!

I'd have thought that more performance across the rev range and much less maintenence would have been enough.

[Rossvickicampbell]

the advantage of the PVL on my CR250 was simple - I got to fire up and ride each meet while my mate was still playing with plugs, points and sandpaper - to the point of sometimes not even being able to ride!  For us non mechanics the easier the better!  Fortunately mine came with the bike 

Rossco

[colmoody]

As a non mechanic myself I agree with you Ross. Anything that cuts down on service time with the added benefit of maybe more horsepower and better reliability I am all for. Just not sure if Johnny O is on our wave lenght at this point in time. Be interested to hear the outcome of his perceived electronic ignition problems. With a bit of luck it will be an easy fix.

[jimg1au]

ross
points on a cr250 are the easist to work on once you get clued up on what to do.
all you need is screwdriver.feeler guages tally ho papers.thats it.
cheers
jim

[JohnnyO]

Col i haven't really got any new info on what the problem is but i spoke to an expert who rewires stators and i'm just going to check the airgap again between flywheel and stator and if it's within spec i'm sending the stator to him to be rewired. Apparently he's done a few PVL's for go kart guys.

[Rossvickicampbell]

but thats the point Jim - I didn't have to?

[jimg1au]

ross i nknow that its your mate i was talking about.
1 of my crs has points the other has cdi both are easy to start.
cheers
jim