Questions: Pilot jets and fan switch ...

Jim Moore · April 28th, 2021, 03:38 PM

Hi guys,

I'm in the process of bringing a Y2K Ninjette back to life. I got it started a few days ago (Yay!). It's running, but it seems really lean at idle. Slow coming off idle, and it hangs on the way back down. The carbs are clean, it has a new stock air filter, the F-A screws are about 3 3/4 turns out, so I don't have much more room there. It occurs to me that I may need to simply go to the next size pilot jet. Is that done on these bikes? I've had other bikes where it was done as a matter of course because they're set lean from the factory. If yes, what is the next size and where do you typically buy them?

On to the fan switch. The engine got pretty hot today in the garage, but the fan never came on. I was able to jump the switch to get the fan working. The fan itself is OK. I noticed that the temperature barely came off the left stop, even though it was pretty hot. Do I have a bad fan switch? Does the temperature gauge take its data from the fan switch, or from somewhere else?

Thanks in advance,

ducatiman · April 28th, 2021, 04:53 PM

I'll comment on jetting (only)....

an otherwise stock EX should not require up-jetting. Provided carbs are, in fact, truly clean. I'd dissuade compensating for other (transition and pilot) circuit related issues as the bike, at one time, ran awesome with OEM #38 pilot jets.

SibSerge · April 28th, 2021, 06:14 PM

The temp gauge and fan switch are totally independent. The gauge is in the thermostat housing , the fan switch is in the radiator on the left side. My fan comes on when the needle is around the middle of the gauge face.

Jim Moore · April 29th, 2021, 02:46 AM

Thanks fellas.

April 28th, 2021, 03:38 PM	#1
Jim Moore ninjette.org member Name: Jim Location: Jax, FL Join Date: May 2012 Motorcycle(s): 2000 Ninjette, 98 CBR600, 98 VFR800, 2000 BMW R1100RS, Kymco Movie 150 Posts: 146	Questions: Pilot jets and fan switch ... Hi guys, I'm in the process of bringing a Y2K Ninjette back to life. I got it started a few days ago (Yay!). It's running, but it seems really lean at idle. Slow coming off idle, and it hangs on the way back down. The carbs are clean, it has a new stock air filter, the F-A screws are about 3 3/4 turns out, so I don't have much more room there. It occurs to me that I may need to simply go to the next size pilot jet. Is that done on these bikes? I've had other bikes where it was done as a matter of course because they're set lean from the factory. If yes, what is the next size and where do you typically buy them? On to the fan switch. The engine got pretty hot today in the garage, but the fan never came on. I was able to jump the switch to get the fan working. The fan itself is OK. I noticed that the temperature barely came off the left stop, even though it was pretty hot. Do I have a bad fan switch? Does the temperature gauge take its data from the fan switch, or from somewhere else? Thanks in advance, __________________________________________________ Jim Moore Jax, FL

April 28th, 2021, 04:53 PM	#2
ducatiman ninjette.org certified postwhore Name: Gordon Location: new york Join Date: Sep 2009 Motorcycle(s): '95 DUCATI 900SS/SP '07 DUCATI SS800 '19 HONDA CBR650R Posts: A lot. MOTM - Nov '18, Mar '17	I'll comment on jetting (only).... an otherwise stock EX should not require up-jetting. Provided carbs are, in fact, truly clean. I'd dissuade compensating for other (transition and pilot) circuit related issues as the bike, at one time, ran awesome with OEM #38 pilot jets. __________________________________________________ gordon@customcarbservices.com Custom Carb Service www.customcarbservices.com
	1 out of 1 members found this post helpful.

April 29th, 2021, 02:46 AM	#4
Jim Moore ninjette.org member Name: Jim Location: Jax, FL Join Date: May 2012 Motorcycle(s): 2000 Ninjette, 98 CBR600, 98 VFR800, 2000 BMW R1100RS, Kymco Movie 150 Posts: 146	Thanks fellas. __________________________________________________ Jim Moore Jax, FL

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April 28th, 2021, 06:14 PM	#3
SibSerge ninjette.org member Name: Sergey Location: Ontario, GTA Join Date: Oct 2019 Motorcycle(s): Ninja ZZR250 (EX250H) Posts: 213	The temp gauge and fan switch are totally independent. The gauge is in the thermostat housing , the fan switch is in the radiator on the left side. My fan comes on when the needle is around the middle of the gauge face.