This goes on a bit but please bear with me, I'd like to know if anyone has had similar problems and solved them.

 

I got my 2009 in the middle of last year.  Starting was never the best (I know the correct technique of no throttle etc) but has deteriorated to the point where at two trials last week I had to reset the system several times at almost every section to get the thing to go.  Once running it does so perfectly with no suggestion of a problem.  New plug and valves correctly gapped, sufficient slack in the cable, properly oiled air filter.

 

Yesterday I finally managed to get use of a revcounter – tickover was rather high at 2200 but now set to 1850.  It then started a few times, hot, with the apparently normal half kick.  Exhaust gas analysis was OK.  Great.

 

A few hours later (cold) it was back to needing several resets.  I checked the spark and, with the kill button disconnected, there was neither sight nor sound of a spark in a dark garage (several plugs tried).  I have taken apart every electrical connection I can get to but they are all clean.  I have remade the HT connection to the coil.  It eventually started after 20 kicks afer showing signs of life.  Once hot it started with 4 kicks several times on the trot despite still no visible spark. 

 

I’m a bit mystified so all suggestions welcome.

 

 

 

Edited April 2, 201610 yr by 2stroke4stroke

Bad earth at ht coil perhaps

That was my thought, cleaned up today but was not bad.

You said that several plugs were tried, were they new spark plugs ? Try again with a new plug gapped to approx. 0.40mm  If there is no spark then try the easy things first, wiring connections, spark plug cap and re-check all chassis and engine grounds with a meter. Good luck.

Fresh out the box and known good used. Connections and plug cap done as far as possible. Earth done.

It seems to be an intermittent spark (as clearly there is one eventually) but there is no sign of it once running, runs like a train. Mysterious.

Fuel pump to wiring harness connector. That will produce no or weak spark if dodgy, but runs ok when it get going

Edited April 2, 201610 yr by jrsunt

I was just thinking the fuel pump connection...

 

Not likely but you could consider checking the bank angle sensor... Disconnect and bypass by connecting/shorting the 2 outside connectors together.

No bank sensor so I'll have a fiddle with the pump wires tomorrow - there is a sharp fold in them which attracted my attention the first time I lifted the tank but as the pump seemed to work I did not investigate. I didn't consider then that it might affect the spark.

Hi

 

This thread http://www.trialscentral.com/forums/topic/56730-4rt-no-spark-help/page-2#entry404207 that I comment may give you another direction to follow in terms of diagnostic possibilities.
I'm not saying it would solve your problem, but it is good with another objective view on how to troubleshoot such a problem as missing spark.

Regards
Honda Freak

It took a bit of starting today but once warmed up I tried jiggling the pump connector and wires to no effect so seemed OK. In fact it kept running for a few strokes when I pulled the connector apart so the sparks must have been there.

During the trial I got a few (rather more than usual) first kick starts but otherwise it was taking four kicks though only needed reset twice during the event so something has improved.

I had been wondering last night if it could be a fuel filter problem where once running there was enough suck to draw petrol through but not enough at times when kicking before the motor was actually running. I shall investigate when I have enough time between events to risk encountering problems doing that.

Thanks for all the advice guys but keep it coming if anything else occurs.

It sound like you have a good idea there, fuel flow could well cause a symptom of this type. hope you get it sorted soon.

presume you are starting the bike in neutral?

Yes, but that's another puzzle as to why Honda can't (due to clutch drag) produce a trials bike that will consistently start in gear when they have made millions of road bikes that would.

My rmz450 won't start in gear when hot,think the minimal clutch drag is enough to stop it turning over fast enough

Yes, but that's another puzzle as to why Honda can't (due to clutch drag) produce a trials bike that will consistently start in gear when they have made millions of road bikes that would.

Strange, I never had problems starting my 2008, 2015 or my new 300RR when its in gear.