Author Topic: bike wont start on button help needed (Read 5128 times)

speedy gonzalais · « **on:** September 25, 2008, 11:04:23 AM »

With the new engine in things cant really get worse its the 650 AGAIN

the bike just will not start on the button hot or cold it turns over fast but just wont fire up but will on a push start instantly the things ive checked so far: the carbs, plugs, and battery no problems there any1 else ever had this problem

cheers dids

speedy gonzalais · « **Reply #1 on:** September 25, 2008, 02:40:19 PM »

update the bike will start on the button but only after a real good thrashing on the motorway but if i ride to the shop and back nomatter how warm the engine is she just turns and turns but wont fire up this is really really strange never come across this prob in the past well i have come across a couple of bikes that done this but was due to bad compression but my readings are just under 150 on all cylinders

any ideas people please

Honda_Nut · « **Reply #2 on:** September 25, 2008, 02:52:05 PM »

Sounds to me like the starter is dropping the voltage to the coil - resulting in no spark. Are you sure it's wired correctly? Does the headlight shut off when you push the starter button? measure voltage at the coil when turning the starter to verify.

speedy gonzalais · « **Reply #3 on:** September 25, 2008, 02:55:40 PM »

i tested voltages earlier its 11.6v at the coils when turning over

CB750F2 · « **Reply #4 on:** September 25, 2008, 02:56:56 PM »

Your battery volts may be dropping too far with the starter motor engaged - check with a volt meter with the starter engaged. Hook a battery charge to the battery and charge for half an hour and retry. Another possibility is that on pushing the starter button you may also be disturbing the "kill" switch wiring thus effectively trying to start the bike with the "kill" switch in th e"kill" position. Pleses note I know nothing about 650s - my experience is with 750s so take this advice as a general nature. Pat

CB750F2 · « **Reply #5 on:** September 25, 2008, 03:03:43 PM »

Another possibility is that coils with ballast resistors have been fitted. These resistors may need to be bypassed when starting. Has this just started to happen? Pat

speedy gonzalais · « **Reply #6 on:** September 25, 2008, 03:08:08 PM »

i charged the battery all night it still wouldnt go in the morning ive tested the power output of the altenator and thats 13.2v at 1500rpm. when turning the engine over the coils read 11.6v and the battery 8. somthing i did find that rather strange but tried a booster pack and still no joy. I put spare plugs in ht caps and there is a nice blue spark, its getting to the stage now where i just wanna pull the engine and strip it again, im gonna be going on a long road trip soon and want the bike to make it lol.

CB750F2 · « **Reply #7 on:** September 25, 2008, 03:26:03 PM »

OK, you have a good spark with the motor turning over? Assuming that the answer is yes I would first try to start and then remove the plugs to sse if they are wet with fuel. If they are dry then then you need to investigate why ther is no fuel getting to the cylinders - float level too low, idle jets blocked, fuel lines blocked. You say that it will push start. Does it fire immediately the clutch is engaged or does the mmotor have to turn over a few times? Pat

speedy gonzalais · « **Reply #8 on:** September 25, 2008, 03:27:38 PM »

as soon as i let go of the clutch it starts instantly no problem.

scunny · « **Reply #9 on:** September 25, 2008, 03:38:48 PM »

try the starter motor from your junk motor, the one in the bike may be drawing to much current

CB750F2 · « **Reply #10 on:** September 25, 2008, 03:40:23 PM »

You say that your battery drops to 8v when the starter motor turns over. This is too low. A good battery fully charged will hold 9 to 10 volts when starting. Try another battery if you can. Temporarily hook up a car battery if you can. Pat

CB750F2 · « **Reply #11 on:** September 25, 2008, 03:52:27 PM »

You could try running a temporary wire directly from the +ve battery terminal to the coils. On the 750s this is a black/white wire. This will reduce any voltage drop in the harness wiring and switches. Pat

speedy gonzalais · « **Reply #12 on:** September 25, 2008, 03:58:48 PM »

8v was a good 15 minutes after turning over and fiddling, the battery is on charge again il try in the morning and try swapping the starter aswell

thanks for the help guys will update tomorow

cheers

Hush · « **Reply #13 on:** September 25, 2008, 04:06:17 PM »

On our 650's the starter wire is yellow and red stripe, it earths the starter motor.
Find the y/r wire in the loom, its under the tank as I recall and earth it with the key on, bike should start!
If the kill switch is somehow getting mixed in to the starter circuit then this should either prove or disprove it.
There is a black common wire between the two so this isn't totally out of the picture.
You could also try pulling in the clutch lever as you press starter, our bikes have that wierd safety system where they wont start in gear without the clutch activated, maybe it is out of adjustment, just a thought.

speedy gonzalais · « **Reply #14 on:** September 25, 2008, 04:16:31 PM »

the clutch lever switch is ok the bike wont turn at all if in gear and clutch is released, i dont think its got any thing to do with the kill switch as theres a spark, Il be out there and on here tomorow ive got lots of ideas and things to try from here

cheers guys

bryanj · « **Reply #15 on:** September 26, 2008, 05:29:40 AM »

Only 2 reasons for no start on button but start on push

(1) Battery volts at coil low

(2( low compression

speedy gonzalais · « **Reply #16 on:** September 26, 2008, 01:54:41 PM »

Update: whilst fiddling around today i left the engine running for a while and then i noticed this black tar dripping from the bottom of the bike and upon further inspection i traced it up the back of the mud guard past the battery to the bottom of the regulator that was so hot the tar that seals the under side was melting?

Ive gone over the whole electrical system and cant find any thing that could have caused this, i got i tiny bit of suspicion on the altenator but then surely it couldnt kick out enough juice at 1100rpm or could it?

Honda_Nut · « **Reply #17 on:** September 26, 2008, 02:41:17 PM »

A shorted rotor or stator coil?

CB750F2 · « **Reply #18 on:** September 26, 2008, 03:35:20 PM »

According to th 650 wiring diagram the requlator housing also contains the rectifier. The requlator/rectifier and alternator will need to be tested to see what is damaged. I suggest that for now that you disconnect the two plugs connecting the harness to the regulator/rectifier and continue with sorting out the no start with the electric start problem - use a external charger to recharge the battery when required. Once that is sorted out I will try and help you test the regulator,rectifier and alternator - you will need a multimeter to do this. I do not have a wiring diagram of the internals of the regulator/rectifier so hopefully some one will post one for you. Pat

speedy gonzalais · « **Reply #19 on:** September 26, 2008, 04:18:30 PM »

i cant work out what it is the one thats over heating has (OKI MPS200) stamped on the top and i think theres 2 of them one on top of the other on the battery side and next to it is a much bigger thing with thins on it any ideas as to which ones which

cheers

CB750F2 · « **Reply #20 on:** September 26, 2008, 04:33:01 PM »

The OKI MPS-200 are the spark units for your 650 - one for each coil. If you do a search on Google fo OKI MPS-200 you will see a lot of info. Apparently, the overheating of these units os a known problem. So, the Regulator/Rectifier unit is not over heating? Pat

speedy gonzalais · « **Reply #21 on:** September 26, 2008, 04:38:18 PM »

oh so the regulator must be fine then and the spark units are not they may have melted from using iridium plugs maybe or just a common problem ? ive got spares.

speedy gonzalais · « **Reply #22 on:** September 26, 2008, 04:43:30 PM »

another thing i noticed was the bolt holding them on was loose, are they earthed to the chassis ? maybe thats why they melted, and finally could they be the reason for her not wanting to go on the starter?

cheers

CB750F2 · « **Reply #23 on:** September 26, 2008, 04:55:53 PM »

I have no experience with these particular units and I do not know if they are grounded through the frame but they should be tight mechanically to the frame to dissipate the heat. I suggest that for testing purposes replace the iridium plugs with a normal set and try to start - make sure the plug gaps are set. Pat

speedy gonzalais · « **Reply #24 on:** September 26, 2008, 05:02:14 PM »

yea will change the spark units and try the old plugs see if that helps

Thanks guys u have been a great help

News:

Author Topic: bike wont start on button help needed (Read 5128 times)

Honda_Nut

Honda_Nut