!!!Help!!! Bike spluttering, loss of power...

PM sent Shero

I have read your posts and have seen that you have done extensive work to the carbs and also checked exup.. I can only conclude that it is an electrical problem..

Get a good digital multimeter. Check battery volts sitting (ignition on, engine not running) at 12.8volts and dropping off to 12.2 when the headlights are on.

Previously I checked my FZR, the cranking volts was around 10 volts so I think my battery was going off. Started almost straight away though. It got up to 13.8volts at 3000rpm and at idle it dropped back to 11.8 (lights were on).

One other member had sort of similar problems and replaced the battery and cured all. Batteries can die suddenly... In his case, perhaps the battery acts as a lo impedance filter, smoothing the power supply from the rectifier/regulator. As batteries get old, their impedance gets higher and are unable to filter the electrical noise.

FZRs have a TCI digital (read microprocessor controlled or at least integrated circuits) ignition module and could be susceptable to electrical noise. Try another GOOD battery first.

Next thing would be to check the pickup coil (it is in alternator cover RHS of engine) 230 ohms +- 20%, also check that it is insulated from earth (it has to be unplugged to do this)
Magnets are good and strong ?- no rubbish on them.?

Check ignition coils
- primary winding 2.8ohms +-15%
- secondary windings 15Kohms +- 20%

Spark plug caps have 10Kohms resistance fitted inside.

If you don't find anything then try another identical ignition module....

 

I hope it helps but there are no guarantee's - Another suggestion is to get a compression test done and see if there are any issues with the valves.. Compression should be 120-150psi, anything less than 100psi and your in real trouble..

Also check for air leaks in the rubber boot connectors between the carbs and heads and the airbox. Are the vacuum test holes plugged?? Are the carbs balanced (do compression test first, its no good doing if the valves are not correct)

Good luck

 

I seems normal-ish but it is lower than mine...

If you can borrow a known good battery from one of your mates, that would be a good test first up...

 

Hey thats good news.If it fixeds by sunday you should come for the ride.

 

To me it sounds like you've got a mis-fire in one or more cyllinders.
If you've replaced your plugs, then i'd say it might be a coil.

Will be interesting - this is the exact same problem my gf's ZZR has got. i'm about to strip down and clean the carbies, repair the fuel tank (also rusty), recharge the battery (dead), and replace the plugs - all of which you've done [which doesn't make me feel optomistic].

If that doesn't work, then my next guess was the coils - you'll have two of them, and each one controls two cyllinders. You can find them pretty easily - follow the spark plug leads back to two little black boxes. They're your coils.

 

Similar problem

@ Shero

Please let me know how this turns out as it seems I could have a similar problem.

Mine is weaker below 10,000 and now and then it will only tick over on full rev. It usually picks up again after turning off and leaving for a few minutes. Pulling away I have to really rev and slip the clutch, sometimes it bogs down and is slow picking up. <!-- s --><img src="{SMILIES_PATH}/icon_sad.gif" alt="" title="Sad" /><!-- s --> Over 10,000 it seems fine. Could this be the ex-up?

I have cleaned carbs, changed fuel filter, oil filter and oil. Air filter clean.

I will check ex-up, I wonder if that was not workining properly, say stuck open, that it could stop the bike from reving? Will then move onto fuel pump, plugs, leads, battery, coil in that order unless anyone else has any ideas?

Cheers

Rob

 

When I bought my FZR the exup valves were wired up fully open because the cables were snapped. While it ran ok, under load at say under 6000rpm it would seem to lose power like it was flooding and the only way to get going was get back a gear and put some revs on. i couldn't even bet up my driveway in 1st without a run-up.

I put new cables in and it made a word of difference.

 

There were broken bolts in my carbies! <!-- s:shock: --><img src="{SMILIES_PATH}/icon_eek.gif" alt=":shock:" title="Shocked" /><!-- s:shock: -->

 

<!-- s:shock: --><img src="{SMILIES_PATH}/icon_eek.gif" alt=":shock:" title="Shocked" /><!-- s:shock: --> indeed!