sluggish, weighed down, low power....

i know its hard to tell without riding it... but... my 81 kz750 ltd h2 has been riding sluggish lately... she just doesn't have the power she had a month ago... used to nearly take off from under me... now... it just kinda putts forward....i donno if its an engine problem or not.... i'm into working on my own bike.. and... the only experiece i've had is with my own bike... so i'm a rookie mechanic.... but..here's a few things i can let you know..... keep in mind i'm looking for reason in a DRASTIC loss of power...

oil was changed earlier in season, and level was always watched (it DID go through some oil) ran about 1,500-2000 miles this year...

replaced rubber carb boots connecting to the carb to the engine because originals leaked air (which reduced power) all are tight and not currently leaking

i've threw some sea foam in the gas and a lil in the oil AFTER i noticed she was running slow (the thought of carbs maybe getting some build up could reduce power)

i HAVE had electrical problems including one of the main power leads nearly rotting through less than a month after i bought it on saint patricks day 2009... and i wouldn't be surprised if i might have another electrical problem... i plan on gutting most of evrything electrically this winter... could this be a problem reducing power? maybe misfiring?

i DID replace all 4 spark plugs in July....

replace the clutch cable in June

replaced the throttle cable in late september... the throttle cable broke the day after i noticed loss of power... (any correlation?)

things i haven't done (that i THINK i might need to look into):

checked fuel filter
cleaned carbs

sooooo how bout some professional opinions???? what might make my bike DRASTICALLY lose power??? i want to get her back to life!! she's a great bike!

I'm dumber than a short rake handle but if I were you the first thing I would check is the fuel filter. I'd also drain each carb individually into a clear jar and let it set for a bit. Look for sediment in the bottom of the jar. Next thing I would do is get her warmed up and then take an empty Windex bottle and put some water in it. Spray a little on each head pipe. If it doesn't sizzle right off into steam then that cylinder is probably not firing. Check for spark in any cylinder that's not firing. After I did all that I'd wait for the real experts on this board to come along and help.

Check valve adjustments then a compression check. Look at what the plugs look like now Clean or sooty. also check voltage at the coils ..One more thing lube your timing advancer Has they tend to stick. then if alls well move to carbs..

sudden, dramatic power-loss (if it still runs smoothly)makes me suspect cam-timing jumped...

tjk.... it seems like its running smooth... no pings or ticks... just....... no power.....

and i'll look into the fuel filter, draining carbs, etc stuff... i drained the carbs when i bought the bike... aaaand... fuel filter LOOKS easy... never messed with it though...

thanks for the suggestions..... anyone else have any recommendations for me???

Since this happened about the time you had throttle cable issues, kind of makes me think you may have something wrong in that area, are you sure the throttle is opening up correctly and all the linkages are working as they should.
Also look at the choke mechanism, could it be on thus causing it to run rich.
And as stated, do a complete and through tune up including, NEW plugs, check the valves. run a compression check, make sure the timing has not moved ( had that happen once ), check the voltage to the coils and clean up the electrical system.

hope this helps

i have never touched the cam timing.... i have tightened my drive chain 3 times in the 7 months i've had it.... about every other month (i need a new chain and sprockets... i KNOW i need that)...
throtle is good... not sticking... my particular model only has the pull (not a push and a pull).. my throtle seems to have good action.. not loose... not tight... works normal... and i did check both connection ends.. they're both installed correctly....
choke is not an issue... i have to run the choke to start the bike.... and i know its off when i ride....
i planned on doing another set of new plugs a lil closer to the spring riding season...

i KNOW there's electrical problems all over this bike... and i'm wondering if i might not be getting electricity to my plugs for proper firing (as someone mentioned... check for firing)... it seems like i might not be running on all 4.... which would really cut my power down... i've got a bunch of ideas and a lot of maintence and checks to run now... but i'm still open for ideas.... my hope (i hope because i don't know how much time i'll have this winter) is to gut the bike... and maybe run new wires where needed or maybe even the whole wiring harnes...

other things i forgot to mention with maintence i have already done:

new battery (charged and trickle charged at least once per month)

new positive connection coming off the terminal for my main positive power wire

had to run a new wire to the brake/tail light because all positives behind the seat were dead (other than the turn signals)

replaced fuses

replaced headlight (ha ha... i know... shouldn't have anything to do with it)

i installed a LED light on my tach cuz it was out.. (my speedo lights up stock green and my tach lights up blue)

==============

essentially... lots of electrical... and i already know there is more to do... but i've been riding it just fine untill it suddently lost all its power... i have been riding sparingly since the power loss...

in the mean time... keep feeding me ideas guys!!!

VTR BOB!!!! YOU'RE BRILLIANT!!!!!..... #4 isn't firing... dropped some water on the pips after i fired it up!!..... sooo now all i gotta do is have fun with my electrical system..... YAY..... but its #4... i have my old plugs... and i tried 2 of them.. and... its not the plug.. its the wiring....

THANKS!

If it's just #4 that's not firing I'd suspect either the plug wire or the plug cap as the same coil fires #1 and #4. Have you checked #4 plug to see if you have spark?

Smarty Pants,,,LOL


soccerd31 wrote:

VTR BOB!!!! YOU'RE BRILLIANT!!!!!..... #4 isn't firing... dropped some water on the pips after i fired it up!!..... sooo now all i gotta do is have fun with my electrical system..... YAY..... but its #4... i have my old plugs... and i tried 2 of them.. and... its not the plug.. its the wiring....

THANKS!

I'm thinking of changing my user name from Vter Bob to Swami Bob...

ROFLMFAO! :woohoo:

You say the bike runs smooth but #4 isn't firing. I would hate to see what you call rough running.