Curvy sv650 down on power

[mikerj]

If the bike has been standing for a long while, it's probably worth stripping and cleaning the carbs. My dads curvy often runs like a dog when started after standing unused for a few months, and it's always been carb related.

Originally Posted by mikerj

If the bike has been standing for a long while, it's probably worth stripping and cleaning the carbs. My dads curvy often runs like a dog when started after standing unused for a few months, and it's always been carb related.

Thanks, the plan is to start stripping the carbs to clean over the weekend. Hopefully as you say that will sort things out.



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We got the carbs out, initial inspection doesn't show much wrong inside them, jets coming out tomorrow for further inspection. Fingers crossed it'll be purring again shortly.

Hi All, so when looking at the jets and float bowls there was nothing really dramatic to report but we gave them a good clean and blow out with carb cleaner etc.

On testing the Throttle Position Sensor however, following the service manual we should have a range of 3.5k - 6.5k ohms on reading 1.
We ALWAYS have 5.25k ohms no matter where the throttle is.
(Tested with the sensor mounted and removed from the carb)

The second reading as seen in the manual does appear to be ok, it ranges from 0.5k - 5k ohms.

Could this cause our loss of power and hesitation issues? I'd like to think it would! Am I right in thinking this would affect ignition timing?

Having read the manual a few times, I may have misunderstood, maybe the first measurement is always constant, and its the relationship of the second reading at WOT which is important.

Any thoughts:

[embee]

The sensor is a potentiometer with a resistive track between 2 pins (Ohms1), and a wiper contact which slides over the track and thus gives a varying resistance between the wiper pin and the end of the track (Ohms2).

Ohms1 will be a fixed value, somewhere between 3.5k and 6.5k Ohms. The actual value depends on the manufacturing. In your case the track resistance is 5.25k Ohms, that's fine.

At full throttle your Ohms2 reading should be adjusted to give 78% of 5.25k by slackening the fixings and turning the whole pot. IIRC there is actually very little adjustment available in the slots but it should get within range.

Originally Posted by embee

The sensor is a potentiometer with a resistive track between 2 pins (Ohms1), and a wiper contact which slides over the track and thus gives a varying resistance between the wiper pin and the end of the track (Ohms2).

Ohms1 will be a fixed value, somewhere between 3.5k and 6.5k Ohms. The actual value depends on the manufacturing. In your case the track resistance is 5.25k Ohms, that's fine.

At full throttle your Ohms2 reading should be adjusted to give 78% of 5.25k by slackening the fixings and turning the whole pot. IIRC there is actually very little adjustment available in the slots but it should get within range.

Great answer, thanks a lot.

OK then back to head scratching.

[yorkie_chris]

Also, the TPS makes an incredibly tiny difference