Carbs and maybe a too rich mixture

[el milanes]

Hi everybody,

great sunny today, ay? at least here in Wellington

I've just had my old bike serviced. Had had a couple of problems, so it's been a pretty ext(p)ensive one. There was a fuel leak from the carbs, this time, they said. And indeed if I wasn't riding the bike for a week or more, I could easily find an empty tank, all the petrol gone (no petrol thieves around, so far :-).

Since I got her I've had a flat spot around 8000 revs. It was more than a flat spot: sometimes the bike would die (rev counter down to low revs) to recover suddenly with a snap of the final drive chain and rarely, a backfire. Sometimes, it wouldn't recover, until I shifted to a lower gear. With a more open throttle, I was experiencing this problem more accentuated. A friend told me that it could be an electrical thing related to certain peak voltages... I don't have a clue, and neither had they at the shop.
Anyway, after they cleaned the carbs, I was expecting the bike to go better.
But the opposite! I've noticed a loss of power, the bike coffs at low revs (below 8000), if I open the throttle it slows down a little bit, acceleration null. So I have to keep her up high all the time. Plus, with the fuel leak fixed I was expecting to save petrol. The opposite: it's using at lest 10% more fuel: before I expected to do at least 200k on a tank, now the maximum I can do is 180k....

Another friend told me that now the mixture could be too rich, that the carburation must be recalibrated. Is that something that you can do using a screwdriver?

Thank you for your replies! sorry it was too long to read

[sugilite:Me]

does it rev cleanly above 8000?

[MSTRS:Me]

Sounds like carby's to me, since 'cleaning' them made the problem worse.
Possibles - out of balance, worn jets/needles, sticky choke. I am assuming the air filter foam was cleaned/replaced?

[el milanes]

does it rev cleanly above 8000?

Yes, now it has two flat spots: about 5000 (this one when I open wide the throttle) and 8000, and then it's clean up to the red line. But with less power than before. I noticed today on the Haywards hill, 5th gear, open throttle, it was taking ages to rev high

[el milanes]

Sounds like carby's to me, since 'cleaning' them made the problem worse.
Possibles - out of balance, worn jets/needles, sticky choke. I am assuming the air filter foam was cleaned/replaced?

I'm not too sure. They definitely replaced oil and oil filter, but I think this time the air filter hasn't been replaced. I should have thought about that...

[sugilite:Me]

Although having a new air filter will almost certainly help, I feel it is unlikely to be the cause of 2 flat spots.
I'm wondering if your carbs were cleaned and assembled correctly?

[el milanes]

I think yesterday the honest EL250 passed away.
Remember there was a strong nort-westerly last night (at least in Welly).
Well, I was riding up the gorge when suddenly the bike lost power completely. I think there were flames out of the exhaust. Anyway, I managed to turn left on the Johnsonvil turn off and I called the truck.
I turned the bike off and on. When it's off gears, it sounds alright but as soon as you put her into gears and tries to accelerate, it can't pass the 4000-5000 revs. Maximum speed: 60km/h on flat, 30km/h going uphill. I asked the guy from AA (cheers Porirua City Towing), to follow me to see what'd happen and I managed to ride slowly home.
I wonder if the problem is electrical and it can be fixed. Really sad. With a beautiful brand new fron tyre (Pirelli)

[el milanes]

Your power-loss and/or sputtering might be an electrical problem. Maybe something simple: if the bag was on your right, is it possible you bumped your kill-switch? Or maybe you -or the bag- loosened a wire, or pullled a ground wire a bit loose? All these minor things could explain your experience. If you're sure none of these happened, get your electrical / charging system checked out. Ya never know. Certainly losing power, or surging & lagging power, and/or sputtering ...can be electrical in nature. A lack of power [or intermittent power] to your spark-plugs means fuel isn't being burned and instead is left in the chamber - waiting for spark. When you do suddenly get that spark, it'll cause some sputter and/or a power lag/surge ...until the spark/fuel are in sync and your bike then stops flooding on it own.
http://www.bcsportbikes.com/forum/sh...ad.php?t=55599



Excessive internal resistance of the ignition coil will cause the damages described.

Manufacturers use same wiring harnesses for more than one model. The wires you've found are extra or auxillary or accessory leads. Leave them as found.

Measure voltage of the battery with a VOM. Measure specific gravity of battery's electrolyte to determine exact cell condition. Without being there to see and test, I can't accurately say what caused these parrts to fail.

Send me an email and I'll return several info files on electrical testing and more. My email addy is:

mshively1@woh.rr.com

I recommend having a local tech perform electrical diagnosis on the MC. Have it done as an estimate or diagnosis only and make the repairs yourself once you know what needs replaced.
http://experts.about.com/q/Motorcycl...8-kawasaki.htm