Hello all,
I bought an 87 cbr600f1 at the end of last summer and It has been a great bike but... ever since i have owned the bike after a few days of riding (short trips and longer rides) it starts to get on my nerves by not starting. It will start fine up until the moment it doesnt start. After about a week of short trips it will start cranking a little slow but if i ride it to work and back for a few days (about 8 miles) and take a long trip (about 60 miles) I start having problems.
After riding back and forth to work a few days last week on my day off my gf wants to go for a ride so we hope on and it fires right up, hit the highway and cruise about 30 miles out of town down a two lane at around 70 the whole way. Stop to decide where we want to go next it fires right up and we turn around and head about 25 miles back down the same highway at the same speed and stop in a historic district to get some directions hit the loud button and it will barely spin over. Push start it and it fires up w ease (considering I had to push the thing) and we head back home after making a detour (had to push start there too, I knew i would). put it on the battery charger juiced it up and its been fine for the past few days going to work and back.
I had this problem last year on a three day camping trip 4 hours from home last year and we had no battery charger. I Push started it and bravely (or stupidly) rode it 35 miles from camp repeatedly and it ran fine the whole time other than having to push start it. I probably push started it 15 times and it would run like a top but would not charge the battery up enough to start it. I Know that the battery is fine, Its a fairly new unit and i have had it tested. My gut is telling me that there is a bad ground in the charging system but i Know that there must be other possibilities, I just feel that if I had a bad stator it would have totaly crapped out on me by now and the bike would not want to run even when push started.
Sorry for the novel, I was just trying to vividly describe my issues in one shot. Oh, and I dont know if its related or not but the tach does not work correctly. When the bike is off the needle is at 0 but when i Turn the key on it jumps up to 5000 then comes back down and when the bike is running it always stays around 5 grand and the needle twitches a bit if i turn on a turn signal.

 

Here's a link to charging system diagnostics. The symptoms you're describing are
pretty classic to a failing r/r. It's also possible the stator has a bad leg as well.

Charging System Diagnostics - Rectifier/Regulator Upgrade - Triumph Forum: Triumph Rat Motorcycle Forums

Before you get too deep, check all of the connections on the bikes wiring harness.

Look for loose and/or corroded connections. Pay special attention in looking for any
signs of heat-related damage. Melted/warped plastic/insulation, burnt contacts in the
connectors, etc. That often points the way to failing components, connected to those
points in the system.

Ern

 

well i rechecked my grounds and they were all good. I checked the charging voltage and it would not go over 12.76 volts so i ordered a R/R last night. I am pretty confident that that is my issue. I found a nice clear strip of road last night on my way home last night and and climbed hard on the throttle and under a hard load it starts breaking up at high rpm indicating to me that there isnt enough juice to the ignition system under those conditions to burn the mix in the combustion chamber. After i got home i tried to restart it and sure enough it wouldnt restart. I know there is still a chance that it could be a weak stator but I found a new R/R for $53 and some change so i figured that was cheaper and more likely than a bad stator so we will see what happens. I really hope this solves the issue.

 

well i found a good deal on a new R/R so Im gunna try that. After checking some more the resistance was very high on the unit so im thinking that is the problem.

 

you can check the stator. each pin should have continuity to each other, and no continuity to ground. if there is a short to ground, it can fry a new r/r.

 

+1 demon. My r/r was toasted, replaced it. At the time the stator tested fine. 6 months later...stator developed a short and dragged the new r/r with it.

So double-check it, now, since it's easy. If it checks out fine, then keep an eye on it for a while, just in case.

Good luck, Ern

 

thanks for all of the helpful info. i will let you guys know what happens.

 

i had a similar problem. it would start only if i had it on the battery tender. i had to push start it everytime i wernt somewhere.. i just bought a wiring harness on ebay and its been fine since

 

I would like to thank you all for your help. My new r/r was in the mail when i got home from work yesterday and since i had the day off i went ahead and swapped it out. Now that it has enough juice for the ignition sytem (13.0 v just off idle and a touch over 14.0v over 5k) from the lower mid range to top end its like riding a different bike. It sounds much more smooth and what i used to think was a small tuning issue with what sounded like a slight cough in the higher revs has dissapered and been replaced by strong, smooth much more linear power.
Now that it is charging (i know because the battery was dead and i had to push start it after installing the new r/r and only riding it about four miles it fired right up after shuting it of when i got back to my apartment) the disturbed, ulcer inducing super paranoid part of me has already kicked back into overdrive. Now that it is charging again and apparently very quickly, do you think i should be worried about my 25 year old wiring? As i previously mentioned I only saw it get to just barely over 14.0v when the revs were brought up but that was with a weakly charged battery. i figure that I will check it again after i charge the battery at work tomorrow and see what it shows. I checked my stator again while swaping out the r/r and no continuity to ground but continuity through all combinations of the three pins. so i think im ok there but i will keep an eye on it.
Another question that I have is about my new r/r. It came to me in a yellow accel box and the part number sticker says 87-90 cbr600f high performance regulator/rectifier blah blah blah. But it did not have the additional green wire coming out of the plug with an eyelet on it that goes under the head of the bolt that holds the unit to the mount. Is this normal for aftermarket r/r units? also the bolt holes where the mounting bolts go through the unit were not as tall and my factory bolts were to long for the new unit. Thankfully i found some m6 x 1.0 16mm bolts that worked perfectly but if i hadent been somewhere that had those laying around i would have been screwed (no pun intended). Does anyone have experiance with the accel r/r units? do they last very long or am I going to be replacing it every week or every month? Again sorry for the long post but i like to get everything out at once. I would also like to thank you all for helping out a forum newbie again.

 

never had a accel r/r, but the green wire is a ground. the unit may be internally grounded, thus the external ground wire is not needed. just be sure that where its mounted to the frame, is clean and tight so it makes a good connection.

demon