Lots of repairs...Still terrible low end power

[johnfellows]

Hello all, so I got my 1994 FZR1000 out again this season. Last summer I went through a lot with this bike including carb cleaning/rebuilding/syncing, new battery/remanufactured alternator replacing (The old alternator started overcharging and frying wires), resoldering all the wires it fried, new spark plugs. The mechanic said the bike charges a little low at idle but is fine by the time it hits 2k rpm (14volts If I remember correctly?) and it no longer drains the battery sitting, so all the shorts are gone. The bike starts up well and the engine sounds great, but I have very little low end power. On top of no low end power, If I go to give it gas anywhere below 4k rpm in 1st gear there is a about a 1 second delay between throttle and the engine starting to rev, bogging? There is no delay when it is in neutral though.
Once the bike gets to 4-5k rpm it starts making decent power until 7-8k when its flying and the wheel is lifting.

What else could be the problem? I've watched other fzr 1000 videos online and they seem to make plenty of power right from idle, where as mine feels like a clogged 250cc until 4-5k rpm. Only things I can think of left is the exup valve not working right (it does make a ticking sound at idle) or the remanufactured alternator not making enough charge at idle (but if its fine by 2k rpm that seems odd too) The bike only has 9k miles on it.

EDIT: Took it out again. The problem only happens when the bike is low rpm AND I give it full throttle. If I go to give the bike full throttle from a stop in 1st gear it sputters to all hell until 4k rpm and then takes off. If I let off completely and hit full throttle again while cruising at 4k rpm it still does it, but a miniscule amount. It had this problem before and after the carbs were cleaned twice so don't think it's a clogged jet. Now I'm thinking it's either getting too much air or not enough fuel.

[DonTZ125]

These are high-revving bikes; giving it a handful of throttle at off-idle and expecting to do anything but laugh at you isn't operating it correctly. That said, have you checked and adjusted the EXUP? Once that's sorted, pull the airbox lid and filter, then free-rev and watch for the slides to lift. If they don't lift,or don't lift together, check the carb diaphragms and the o-ring to the vacuum-chamber port.

[johnfellows]

I have not checked the EXUP valve yet, been meaning to do that. I took a multimeter to the battery and It's only charging about 11.7 volts at idle and 14.6 once it hits around 4k rpm. So I'm guessing my problem is still electrical and the remanufactured alternator I got is garbage :/ I guess I should also state that it's almost as though the bike is misfiring when I go WOT in low rpm, not just that it doesn't make a a lot of power. Could that low of voltage be causing this issue?

[DonTZ125]

14.6vdc at 4k RPM is pretty much perfect - like the engine, the alternator has to be spinning at a minimum speed to get out of its own way. 11.7v at idle says to me your battery isn't holding a charge, or you're spending too much time at 2k to actually charge the battery. A wasted spark ignition system is very hungry, and the headlights don't help. Yes, you are having spark issues due to power starvation. Do a full battery inspection, then take it for a ride where you keep the revs up!

Between poor spark and (presumably) a mis-set or malfunctioning EXUP, I'm surprised the bike hasn't told you to get off and walk!

[johnfellows]

Hmm that makes sense, and the bike has does some pretty funky stuff to me haha. With the bike off the battery is at about 12.17 volts, which ive heard is also low. Although wouldn't a faulty battery cause startup issues instead of the ones I'm having? Wouldn't the low charge at idle be caused by a faulty alternator?

Oh I just realized the symptom I was having before was exactly the same with my previous faulty alternator on (which was around 14 volts at idle but 18 at revs, which fried the last battery) So In both cases am I experiencing the symptoms of a bad battery?

[DonTZ125]

A fully charged battery should read about 12.8v, and yes, it would cause starting issues. As I said, the alternator needs to be spinning at a minimum speed; this is the reason that the charging system is tested at 3-5k rpm, not idle. Yes, 18v will kill your electrical system, including the battery.

Like I said - test / inspect your battery, including ensuring that the terminal bolts are tight. Also, inspect and adjust your EXUP - if the valve isn't closing properly at low revs, the engine will NOT be happy at the bottom end.

[e30isking]

Sounds like carburetor issues...

[TomcatMJ]

14 V in idle and 18 in revs? Sounds more like a regulatorproblem than like an alternatorproblem...ok, in the fzr 1000 its in the same assembly, but if you gave it to a serviceshop to rework the alternator maybe they checked the coils and rewinded them instead of reworking the regulatorpart as the order possibly said "rework the alternator" instead of "check the whole assembly and rework the defective parts"?

[johnfellows]

Sorry for the confusion. The alternator currently on the bike is a re manufactured one, which is the one with 11.7 volts at idle. I still I have my original bad (overcharging) one, which is currently at an electric shop having the regulator replaced, and I'm hoping putting that back on once fixed will solve all of this.

to Don, shouldn't these bikes also be charging at idle as well though? and what else could 18v likely have killed on the bike I should inspect?

[DonTZ125]

No. Below some minimum RPM, the alternator does not produce enough power to supply the electrical demand of the bike. This threshold is generally between 2-3k. Below that, you're running off the battery.

Overcharging to that level damages *everything* from connectors to the TCI to the tach to the relay assembly. That said,the fact that it runs better above 4k suggests you got off lucky.

[johnfellows]

Cool thanks for the info. So since all the melted wires were found in the harness and the bike no longer drains the battery sitting (i.e. nor more shorts) I should be in the clear from the overcharging damage? and I'm guessing the symptom I've had all along then is multiple bad batteries from the original overcharging alternator. Guess I will get yet another battery once I get my old fixed alternator back and hopefully all this should be over with. The mechanic I've been bringing the bike to said he's about to give up on it . That was after the original mechanic at the same shop walked out because of my bike! hahaha