Fault diagnosis - help desperately needed pls..
 

Ok, so having a few sleepless nights last week and finally making the decision to end my 4 year relationship and come to the AR alone Ive had two aborted attempts to get there - yesterday I got to Bradford and the weather was horrendous so I detoured and spent the night with my sister in Darlington, but more importantly Friday Id done 110 miles when he bike cruised to a halt on the M62 and it was home on the RAC truck.

So, after tears, tantrums and much self-pity I now need to try and work out whats going on with my bike and thats where I need your help please.

Its a 98 CBR600F nearing 18k miles. Bought in march and ive since had the following issues -

June - Reg/rec died and boiled my battery so both were replaced although only with cheap replacements.

3 weeks ago - Loss of power when riding and cruised to standstill. Looked in tank and appeared empty. Would start but soon cut out. 30 mins later with more fuel and started fine.

The following day - rode 70 problem-free miles then went to accelerate but no power and bike cruised to halt. Would start but then cut out before I could get it into gear. Left for an hour and a half by which time it started and got home fine.

Thinking that there may be some crap in fuel filter from running low the day before I removed tank, cleaned out fuel tap, checked fuel hoses and replaced fuel filter.

Several problem-free rides over the next week.

Then Friday - Was 110 miles into my journey to the AR, then whilst travelling about 30mph in queue on m62 bike lost power and I managed to get to hard shoulder as it came to a stop. I automatically assumed it was the same fuelling problem as before and replacing fuel filter hadnt rectified it, but when I went to try and start it again there was total loss of power, wouldnt even try and turn over. Neutral light came on but dimmed when i pressed the start button and silence. So I assumed that there must be an electrical fault.
However, by the time we got it back home (5 hours later:rolleyes:) it was trying to turn over again, just not quite enough power. So I charged battery overnight.

Yesterday - With battery fully charged the bike started first time but sounded a bit lumpy. Kept rumming as long I kept the throttle open but as soon as I closed it the bike spluttered, revs dropped and it cut out. Did this everytime I started it.

Today - just tried it again, started fine but very lumpy. After a few seconds of spluttering revs drop and cuts out. It seems to want to run but cant.

Sorry for rambling on but I need to sort this myself (no way I can afford for anyone else to sort it :-() so have tried to give as much detail as I can.

Im 90% certain it has to be fuelling but dont know where to go from here - crap in the carbs maybe??

Would love to hear your opinions/ suggestions, but sensible ones only please!!:-)

Thanks, a very despondant KJ xx

Re: Fault diagnosis - help desperately needed pls..
 

Dont know about that model but a couple of things spring to mind.There still seems to be an electrical problem as you describe something like a flat battery while out on a long ride,and it being able to start next day after a charge.A multimeter to test that system would be good.Secondly it doesnt run properly either,which could be a follow on from the leccy problem,or might be another issue.Running out of fuel and getting carp in the system is one thing,and could there be lots more carp coming through from a badly corroded inside of the tank?Or could water have got in the fuel?
Having said all that Id check the leccy first.

Re: Fault diagnosis - help desperately needed pls..
 

The tank looks absolutely pristine inside and if any water got in it could only have been a couple of drops.

I got a multimeter and checked the battery - 12v off the bike, 12v at idle (when it would idle!) and 12v at 4k rpm. I checked these yesterday, today I cant even get it to idle or run long enough to get it to 4krpm :-(

Re: Fault diagnosis - help desperately needed pls..
 

A fuel filter wont stop all the grunge getting in the carbs.
Clean them out,
"crap in the carbs maybe??" [-X will only clog them lol

Re: Fault diagnosis - help desperately needed pls..
 

A good battery 13.2 volts when its charging needs to be around 14.7 volts

Re: Fault diagnosis - help desperately needed pls..
 

it definitely sounds electrical to me, at 4krpm shouldn't the multimeter read more than 12v? i'm not an expert and perhaps the battery after a lay off will just have enough charge to turn over. i thought my electrical problems were battery related and tested it, 12.06 off bike same at idle, but steadily climbed to around 13.5-14 v at around 4-5krpm. sorry i don't have a definitive solution for you, i've for sure shared your despondancy the last 5 days with my own electrical problems!! :/

Re: Fault diagnosis - help desperately needed pls..
 

They are very bad for coils breaking up under load which also causes spark plugs to arc out hence how you won't get it to 4k , if you can get a hold of other coils even just to try i'm pretty sure you'll find this is prob your main cause.

Re: Fault diagnosis - help desperately needed pls..
 

As stated, those voltages are way to low! sort that our first.

Re: Fault diagnosis - help desperately needed pls..
 

Thanks for your help guys but i think ive solved it and in doing so proved myself to be the biggest numpty in the world!!!

The reason there is no fuel getting through is that my fuel switch was turned to OFF!!!! Now i never ever turn it off so I guess the RAC guy did which explains my fuelling problems since getting it back. I'd checked the kill switch a dozen times but never thought to look at the fuel tap, DOH!! But its ok, I feel suitable embarrassed :oops:

Now the bike will run again ive been able to check the voltages and my reg/rec is definitely dead, only one of the three yellow wires gives a reading, the other two show zero. So thats re-inforced an important lesson and this time I wont get a cheap one from China it'll be a genuine Honda part. I really am my own worst enemy.

Thanks again, KJ xx

Re: Fault diagnosis - help desperately needed pls..
 

Great to see the bikes sorted KJ, such a shame to have not made it to the AR, see u next year i guess :)

Re: Fault diagnosis - help desperately needed pls..
 

:) a suitably easy fix though and i'm sure a total relief... much like my alarm/immobiliser causing me 4 days of grief!!

Re: Fault diagnosis - help desperately needed pls..
 

Can we not just do it all again next month....pretty pleeease????!!!!

Re: Fault diagnosis - help desperately needed pls..
 

If the yellow wires are showing no voltage its going to be your alternator that is duff.The three wires should all show much the same voltage(typically 70 volts AC)when tested with the engine running at about 5000 rpm.You need to put the multimeter across each comination of those wires in turn----1&2 2&3 1&3.

Re: Fault diagnosis - help desperately needed pls..
 

The yellow wires are fine, according to haynes each combination should read 30-500 and they were reading 36-38 so im happy the alternator is good. However on the reg/rec unit itself apparently there should be a reading of 0.5 to 10 ohms between each yellow and the red/white, and the middle yellow gave that reading, the other two didnt.

So i'll replace the reg/rec and take it from there.

Re: Fault diagnosis - help desperately needed pls..
 

Oh right.I had the wrong yellow wires there and the 70 volts reading is what my SV produces.Honda may be different.

Re: Fault diagnosis - help desperately needed pls..
 

You still need to do an alternator output test, the stator resistances are are good indicator but the the proof is in the pudding. As suggested above a typical output would be 70ish volts at 4-500rpm, but three similar results are really what you're hoping to find.

Test as noted above; charge the battery and get the motor running, put meter on an AC setting of about 100V, run engine at a constant speed - say 4000rpm - and test between each pair of alternator wires, A-B, A-C, B-C.

Re: Fault diagnosis - help desperately needed pls..
 

Hmmm..thanks again for your comments. Ive done the test again and each pair is giving a similar result, but only 40v. Is it acceptable because they are similar, if not what is the next thing to check? Ive checked the charge across the battery - off the bike, at idle and at 4krpm its 12v and not budging.
Also Haynes states 0.1 to 1.0 ohms across each pair and they all read 0.05
So where do I go from here. Apologies for my total inability to deal with this by myself. Im happily changing the reg/rec cos im not happy with the cheap one, but it sounds like the alternator is unhappy too...
Thanks, KJ x

Re: Fault diagnosis - help desperately needed pls..
 

That all three are similar is good, but 40V doesn't sound very high. I think you need to find out what the factory specs are, it might be right I suppose.

Re: Fault diagnosis - help desperately needed pls..
 

Re: Fault diagnosis - help desperately needed pls..
 

^ Is that for SV or CBR?

Re: Fault diagnosis - help desperately needed pls..
 

Right, update!!

New reg/rec is on. Battery off the bike showing 12v. At idle 13v. At 2k, 3k, 4k and5k rpm 13volts.
Unfortunately my multimeter doesnt seem to give decimals for dc voltage so figures arent totally precise.

Surely it should be charging at 14+ to keep battery properly charged? Or is 13 enough.....

Thanks, kj xx

Re: Fault diagnosis - help desperately needed pls..
 

When i changed my battery and reg/rec on my sv for new i was still getting low voltages and after loads of testing and faffing it was down to a bad earth. Dont know if thats your problem but its worth a check.

Re: Fault diagnosis - help desperately needed pls..
 

Ive found the problem - my multimeter!! I borrowed one and according to that the battering is now charging at 14.6-14.7v so im happy with that :p

Re: Fault diagnosis - help desperately needed pls..
 

Nice one KJ im happy that you got it sorted and you're happy :D

Re: Fault diagnosis - help desperately needed pls..
 

Bonus :)