+- Fazer Owners Club - Unofficial (https://foc-u.co.uk/mybb)
+-- Forum: Bikes, Hints'n'Tips (https://foc-u.co.uk/mybb/forumdisplay.php?fid=66)
+--- Forum: FZS600 Fazer (https://foc-u.co.uk/mybb/forumdisplay.php?fid=78)
+--- Thread: Bogging down at 8k rpm (/showthread.php?tid=83729)
Bogging down at 8k rpm - Sannox - 06-03-25
Hi all, been a while since I was last on, looked through the threads and can't see anything on this. My 2002 will red line no problem in 1st, 2nd and 3rd but 4th upwards, get to 8ooorpm and it bogs down, all power gone, won't rev past unless I pull in the clutch, roll off the throttle and all good. It's across all four cylinders. Any thoughts?
I still have problems with it sometimes, not always, cutting out under acceleration, sudden and brief, bit of a problem when overtaking, wondering if this is linked to the above issue or not.
RE: Bogging down at 8k rpm - BBROWN1664 - 06-03-25
anything blocking the air intake?
RE: Bogging down at 8k rpm - unfazed - 06-03-25
A few items can cause this, most common one is as BBrown said something blocking the air intake or being sucked into the air intake.
List is endless,
fake plugs,
internal corrosion in the plug caps,
plug caps loose on the leads,
dirt in the carbs being sucked into the main jet,
very worn Throttle Positioner.
There are a few rare cases of a faulty faulty rectifier/regulator and rarer again a faulty Ignitor.
A few cases of overly restrictive air filters, HI Flo in particular had this issue.
Clogged Air filter
over oiled K&N Filter,
Dirty fuel filter,
blocked carburettor vents
Unfortunately no quick and easy solution
Take your pick, it is a matter of ruling out each item, no easy way
RE: Bogging down at 8k rpm - Sannox - 08-03-25
So far, no air intake blockage, got a K&N filter in, lightly oiled and all clean in there, plugs are NGK and measure correct resistance as do the plug caps and coils. Got the carbs stripped, everything looks clean, no splits in the internal rubber, rubber headers have no splits or any perishing, no internal corrosion. Will keep going, got a compressor and blower so can blow through jets etc to make sure all clear. Never checked the TPS in the whole time I've had the bike (15 years) will be checking that once all back together.
RE: Bogging down at 8k rpm - BBROWN1664 - 08-03-25
if you have had it all apart like you say, balance the carbs too.
RE: Bogging down at 8k rpm - unfazed - 08-03-25
(08-03-25, 12:51 PM)Sannox Wrote: So far, no air intake blockage, got a K&N filter in, lightly oiled and all clean in there, plugs are NGK and measure correct resistance as do the plug caps and coils. Got the carbs stripped, everything looks clean, no splits in the internal rubber, rubber headers have no splits or any perishing, no internal corrosion. Will keep going, got a compressor and blower so can blow through jets etc to make sure all clear. Never checked the TPS in the whole time I've had the bike (15 years) will be checking that once all back together.
Due to the design of the TPs the tracks can wear internally or the spring loaded wiper section can weaken. sometimes it throws up a code on the tacho 3000 revs then 0 and then back to normal operation, but not always.
Fake NGK plugs are a big issue, especially those bought on line. You have to be completly sure of where you get them. The problem was so big that NGK put a notice on their website.
How to identify fake NGK SPARK PLUGS - Niterra
There are many videos on how to check them on youtube
Forgot to mention the Diaphragms colu have pinhole splits. Not seated properly, this is unlikely, but possible
RE: Bogging down at 8k rpm - Sannox - 08-03-25
(08-03-25, 03:55 PM)unfazed Wrote:(08-03-25, 12:51 PM)Sannox Wrote: So far, no air intake blockage, got a K&N filter in, lightly oiled and all clean in there, plugs are NGK and measure correct resistance as do the plug caps and coils. Got the carbs stripped, everything looks clean, no splits in the internal rubber, rubber headers have no splits or any perishing, no internal corrosion. Will keep going, got a compressor and blower so can blow through jets etc to make sure all clear. Never checked the TPS in the whole time I've had the bike (15 years) will be checking that once all back together.
Due to the design of the TPs the tracks can wear internally or the spring loaded wiper section can weaken. sometimes it throws up a code on the tacho 3000 revs then 0 and then back to normal operation, but not always.
Fake NGK plugs are a big issue, especially those bought on line. You have to be completly sure of where you get them. The problem was so big that NGK put a notice on their website.
How to identify fake NGK SPARK PLUGS - Niterra
There are many videos on how to check them on youtube
Forgot to mention the Diaphragms colu have pinhole splits. Not seated properly, this is unlikely, but possible
Plugs are ok, got them from M&P, I never buy them online. All put back together and took it for a test ride, seems ok so far, clean revving to 10k (rare it take it past 10k) through the gears. Diaphrams seated ok, if any pinholes, I can't say I noticed any, the rubber was fine as far as I can tell, no cracks nor splits etc.
All I did was clean everything and put it all back together, could have disturbed some tiny bit of residue or muck. I did take out the fuel tap/filter and make sure that was clean too.
Got a compression test kit on the way, will need to balance the carbs, but so far so good.
RE: Bogging down at 8k rpm - fazersharp - 09-03-25
(08-03-25, 09:43 PM)Sannox Wrote:When I am over 10k --- I ain't looking down at the clocks !!!!
seems ok so far, clean revving to 10k (rare it take it past 10k) through the gears.
RE: Bogging down at 8k rpm - Sannox - 09-03-25
(09-03-25, 10:13 PM)fazersharp Wrote:(08-03-25, 09:43 PM)Sannox Wrote:When I am over 10k --- I ain't looking down at the clocks !!!!
seems ok so far, clean revving to 10k (rare it take it past 10k) through the gears.
