Hard starting CBR 929

andi · Crazy Courier Joined: 23 Sep 2007 Karma :

Bike's been a so and so to start for about a year. Also tank mileage had dropped. Sometimes it fires up easy, other times it takes a while but always starts eventually. First thing I changed was the plugs. This seemed to help somewhat. As time passed the problem persisted. Checks revealed a failing charging system. New battery, regulator and generator fitted and all measures correctly. Bike is still erratic on start. Could smell petrol from exhaust too. Fuel pressure regulator was seized so replaced this. Return checked and is not blocked. Tank range is back to normal but still hard to start. Could the plugs be fowled from running with overfueling and weak electrics. Seems logical to me.
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Before: Suzuki GT 185. Honda Superdream 250. Yamaha RD350LC. Suziki RG250. Yamaha FZS600. Honda CBR600F3
Now: Honda Fireblade 929

Kawasaki Jimbo · World Chat Champion Joined: 09 Oct 2015 Karma :

Sounds like multiple issues mostly resolved, but what about valve clearances?

andi · Crazy Courier Joined: 23 Sep 2007 Karma :

xX-Alex-Xx · World Chat Champion Joined: 12 Sep 2019 Karma :

Is it worse when cold, and is the idle speed lower than it should be when it’s warming up? Might need to adjust the linkage to the wax unit.
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DILLIGAF

jeffyjeff · World Chat Champion Joined: 02 May 2020 Karma :

Have you checked for a fat blue spark? Sounds like your problem might be ignition related; coils and/or HT leads.
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History shows again and again how nature points out the folly of men - BOC

sickpup · Old Timer Joined: 21 Apr 2004 Karma :

Have you checked the starter relay?

The charging system on these runs through the starter relay as does virtually all the power for the bike so always worth checking. The pot fills with water and corrodes the connections internally.

andi · Crazy Courier Joined: 23 Sep 2007 Karma :

So went ahead with a plan to check the valve clearances. Got as far as removing the spark plugs and found all so loose that the crush washer was uncrushed Shocked

. I guess the plugs were screwed in finger tight but final tightening got missed Question

One coil was wet suggesting a less than pefect seal. So I tightened them up and now have perfect clean starting and stable idle Cool

. It was hunting a little before Question

. Need a few goes/days before I have full confidence though. Should I name and shame the guy who fitted the plugs? Embarassed

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Before: Suzuki GT 185. Honda Superdream 250. Yamaha RD350LC. Suziki RG250. Yamaha FZS600. Honda CBR600F3
Now: Honda Fireblade 929