Another tuning thread (revisiting old problem)

AncientTV · June 17th, 2011, 01:52 PM

Hey all, since my last post I've combed forums and faqs galore, but haven't found any suggestions that work for me. It's an '07 with a Muzzy and K&N pod, and I'm using the Factory Pro jetkit.

This sums up the issues I was having in that thread:
-Leaky, overfull float bowls
-Poor tuning
-Couldn't ride the bike regardless of settings

Since then, I've replaced the float valves and bowl gaskets, so that's been fixed. And since then, I've been able to ride the bike while the choke is on.

Here's what the bike has started doing since I replaced those parts:
After warmup, the bike will idle at 2k, albeit a bit rough. I can crack the throttle the tiniest bit (it'll slowly rev to 4k and then sputter down), but anything past 1/8th throttle kills it dead. This is with the choke off.
With the choke on (about 80%), the engine revs up to 6k by itself, and I can actually ride it around from there. It will stutter a little between 6k-7k, but as soon as it hits 7k, it shoots off like a stabbed rat. Again, this is only with the choke on. If I shut the choke off, I can't rev it anywhere near 6k.

I know now that my tuning is the only remaining issue, but my question is, is my idle/lowend too rich, or too lean? This is my first foray into tuning, so I'm a bit lost at that part. I'm going to follow the FP tuning guide as soon as I can actually ride the bike without choke, regardless of how inaccurate it is.

tl;dr: Muzzy and K&N pod, runs well with choke, but only above 7k. Dies at choke-less idle if throttle is cracked.

Edit: Current settings are 110 FP main, FP needle at top position, stock pilots at 3.5 turns out.

kkim · June 17th, 2011, 02:14 PM

first, set the idle speed to 1500 rpm after the bike has been warmed up and idling w/o the choke. can it do that?

when you had the carbs apart, did you remove the pilot jets and make sure they were clean?
http://www.ninjette.org/forums/showthread.php?t=65198

check for air leaks at the carbs and also, what is the condition of your slide diaphragms?

what are your current jetting specs?

kkim · June 17th, 2011, 02:19 PM

put the needle clip position in the middle (third position).

http://faq.ninja250.org/wiki/Rejetti...ng_pod_filters

AncientTV · June 17th, 2011, 02:59 PM

Courtesy of Florida summers, it started pouring rain 0.5 seconds after I finished buttoning the bike back up, but I'll update the post when I get to warm it up.
I'm now at stock pilots at 3.5 turns out mixture, middle position on the needle, and the FP 110 main. I cleaned the pilot jet and circuit to be sure, and checked both vacuum diaphragms. They're both sealing and operating correctly with throttle movement, according to the shopvac test.

kkim · June 17th, 2011, 03:23 PM

sounds good... hopefully things have improved and we can move on from there.

there may be a couple of things to address, but lets start with jetting for now.

AncientTV · June 17th, 2011, 03:30 PM

Just rode it a bit. Warmed up, it will not idle below 2500 at this jetting. The throttle butterfly is completely shut. It's also the smallest bit rough sounding.

kkim · June 17th, 2011, 03:42 PM

Quote:

Originally Posted by AncientTV

Just rode it a bit. Warmed up, it will not idle below 2500 at this jetting. The throttle butterfly is completely shut. It's also the smallest bit rough sounding.

"throttle butterfly" meaning the plate in this photo? that butterfly opening amount at idle is controlled by the idle speed control knob.

AncientTV · June 17th, 2011, 03:49 PM

Right, the idle screw is backed completely off of the throttle control plate, so the butterfly is as closed as it gets, and it's still idling at 2500.

kkim · June 17th, 2011, 03:57 PM

look for potential air leaks... carb connections, loose screws.

sounds like an air leak, to me.... I mean, if the butterflies are completely closed, where is the engine getting enough air to run?

what size jets are the pilots?

AncientTV · June 17th, 2011, 04:14 PM

That's what I was thinking as well, but I can't imagine where it would be leaking. The pilots in there are the stock #38s.

kkim · June 17th, 2011, 04:28 PM

as the bike is running, spray some water from one of those Windex type spray bottles at different areas around the carb and intake. when the engine sucks in the water, the idle will be affected. it should help you narrow down where the leak is coming from.

AncientTV · June 17th, 2011, 05:04 PM

According to that, there's a leak around my coasting enricher somewhere. I'll investigate that further.

In the meantime, thanks for the help!

AncientTV · June 17th, 2011, 05:40 PM

So I fixed the vacuum leak, and now it will idle at 1500rpm after warmup, and that's with the idle screw. The butterfly valve is no longer closed

Same story with the throttle, however. I can crack it a little bit to get it to rev up to 3k, but any throttle opening past that just kills the bike. Could there be another leak that doesn't pull air until that point?

kkim · June 17th, 2011, 06:02 PM

can it rev past 3k if you put the choke on while trying it?

AncientTV · June 17th, 2011, 06:09 PM

Not unless the choke is high enough to rev itself, and then it just shoots up to 5k regardless.
Edit: and by regardless, I mean it'll do that without any throttle input.

kkim · June 17th, 2011, 06:14 PM

sounds like your midrange (needle) setting might be too lean. try lowering the clip (towards the pointed end) a step a at time and see if that makes any difference.

you sure your diaphragms are okay? when you installed the FP kit, you didn't drill out the slides by any chance, did you?

AncientTV · June 17th, 2011, 06:28 PM

I'll give that a shot tomorrow. And nope, definitely didn't drill the slides. The diaphragms are supple, uncracked, and in one piece as far as I can tell. Is there any way to check them besides visually and doing this?

kkim · June 17th, 2011, 06:48 PM

nope... a visial is usually good. that's pretty ingenious in that vid.

yes, please post what you find out with the clip positions.

AncientTV · June 18th, 2011, 11:23 AM

It's fixed! This was another case of The Previous Owner Curse

So, while inspecting my slides for the millionth time, I decided to take a gander at the fiche for it. I happen to come across this little part:

"Huh... wait a second."

The previous owner had put 16007 and the needle in the wrong order (the head of the needle was resting on top, instead of enclosed on the bottom, and, being my unobservant self, I had kept putting it back in the same way

Needless to say, that made most of my rev range about half an inch too rich on the needle. I flipped the parts into their correct spots, and now the bike rides like normal!

The tuning is still off, but I can now do what I was supposed to be doing these last couple of months, and tune it to FP's instructions. Thanks for making me obsess about my slides kkim, I don't think I would've looked at the fiche otherwise, haha.

kkim · June 18th, 2011, 12:32 PM

yay!!!

June 17th, 2011, 01:52 PM	#1
AncientTV ninjette.org member Name: nah Location: nope Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250r Posts: 38	Another tuning thread (revisiting old problem) Hey all, since my last post I've combed forums and faqs galore, but haven't found any suggestions that work for me. It's an '07 with a Muzzy and K&N pod, and I'm using the Factory Pro jetkit. This sums up the issues I was having in that thread: -Leaky, overfull float bowls -Poor tuning -Couldn't ride the bike regardless of settings Since then, I've replaced the float valves and bowl gaskets, so that's been fixed. And since then, I've been able to ride the bike while the choke is on. Here's what the bike has started doing since I replaced those parts: After warmup, the bike will idle at 2k, albeit a bit rough. I can crack the throttle the tiniest bit (it'll slowly rev to 4k and then sputter down), but anything past 1/8th throttle kills it dead. This is with the choke off. With the choke on (about 80%), the engine revs up to 6k by itself, and I can actually ride it around from there. It will stutter a little between 6k-7k, but as soon as it hits 7k, it shoots off like a stabbed rat. Again, this is only with the choke on. If I shut the choke off, I can't rev it anywhere near 6k. I know now that my tuning is the only remaining issue, but my question is, is my idle/lowend too rich, or too lean? This is my first foray into tuning, so I'm a bit lost at that part. I'm going to follow the FP tuning guide as soon as I can actually ride the bike without choke, regardless of how inaccurate it is. tl;dr: Muzzy and K&N pod, runs well with choke, but only above 7k. Dies at choke-less idle if throttle is cracked. Edit: Current settings are 110 FP main, FP needle at top position, stock pilots at 3.5 turns out. Last futzed with by AncientTV; June 17th, 2011 at 02:12 PM. Reason: more info

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June 17th, 2011, 02:14 PM	#2
kkim Join Date: Nov 2008 Posts: Too much.	first, set the idle speed to 1500 rpm after the bike has been warmed up and idling w/o the choke. can it do that? when you had the carbs apart, did you remove the pilot jets and make sure they were clean? http://www.ninjette.org/forums/showthread.php?t=65198 check for air leaks at the carbs and also, what is the condition of your slide diaphragms? what are your current jetting specs?

June 17th, 2011, 02:19 PM	#3
kkim Join Date: Nov 2008 Posts: Too much.	put the needle clip position in the middle (third position). http://faq.ninja250.org/wiki/Rejetti...ng_pod_filters

June 17th, 2011, 02:59 PM	#4
AncientTV ninjette.org member Name: nah Location: nope Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250r Posts: 38	Courtesy of Florida summers, it started pouring rain 0.5 seconds after I finished buttoning the bike back up, but I'll update the post when I get to warm it up. I'm now at stock pilots at 3.5 turns out mixture, middle position on the needle, and the FP 110 main. I cleaned the pilot jet and circuit to be sure, and checked both vacuum diaphragms. They're both sealing and operating correctly with throttle movement, according to the shopvac test.

June 17th, 2011, 03:23 PM	#5
kkim Join Date: Nov 2008 Posts: Too much.	sounds good... hopefully things have improved and we can move on from there. there may be a couple of things to address, but lets start with jetting for now.

June 17th, 2011, 03:30 PM	#6
AncientTV ninjette.org member Name: nah Location: nope Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250r Posts: 38	Just rode it a bit. Warmed up, it will not idle below 2500 at this jetting. The throttle butterfly is completely shut. It's also the smallest bit rough sounding.

June 17th, 2011, 03:49 PM	#8
AncientTV ninjette.org member Name: nah Location: nope Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250r Posts: 38	Right, the idle screw is backed completely off of the throttle control plate, so the butterfly is as closed as it gets, and it's still idling at 2500.

June 17th, 2011, 03:57 PM	#9
kkim Join Date: Nov 2008 Posts: Too much.	look for potential air leaks... carb connections, loose screws. sounds like an air leak, to me.... I mean, if the butterflies are completely closed, where is the engine getting enough air to run? what size jets are the pilots?

June 17th, 2011, 04:14 PM	#10
AncientTV ninjette.org member Name: nah Location: nope Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250r Posts: 38	That's what I was thinking as well, but I can't imagine where it would be leaking. The pilots in there are the stock #38s.

June 17th, 2011, 04:28 PM	#11
kkim Join Date: Nov 2008 Posts: Too much.	as the bike is running, spray some water from one of those Windex type spray bottles at different areas around the carb and intake. when the engine sucks in the water, the idle will be affected. it should help you narrow down where the leak is coming from.

June 17th, 2011, 05:04 PM	#12
AncientTV ninjette.org member Name: nah Location: nope Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250r Posts: 38	According to that, there's a leak around my coasting enricher somewhere. I'll investigate that further. In the meantime, thanks for the help!

June 17th, 2011, 05:40 PM	#13
AncientTV ninjette.org member Name: nah Location: nope Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250r Posts: 38	So I fixed the vacuum leak, and now it will idle at 1500rpm after warmup, and that's with the idle screw. The butterfly valve is no longer closed Same story with the throttle, however. I can crack it a little bit to get it to rev up to 3k, but any throttle opening past that just kills the bike. Could there be another leak that doesn't pull air until that point?

June 17th, 2011, 06:02 PM	#14
kkim Join Date: Nov 2008 Posts: Too much.	can it rev past 3k if you put the choke on while trying it?

June 17th, 2011, 06:09 PM	#15
AncientTV ninjette.org member Name: nah Location: nope Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250r Posts: 38	Not unless the choke is high enough to rev itself, and then it just shoots up to 5k regardless. Edit: and by regardless, I mean it'll do that without any throttle input.

June 17th, 2011, 06:14 PM	#16
kkim Join Date: Nov 2008 Posts: Too much.	sounds like your midrange (needle) setting might be too lean. try lowering the clip (towards the pointed end) a step a at time and see if that makes any difference. you sure your diaphragms are okay? when you installed the FP kit, you didn't drill out the slides by any chance, did you?

June 17th, 2011, 06:28 PM	#17
AncientTV ninjette.org member Name: nah Location: nope Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250r Posts: 38	I'll give that a shot tomorrow. And nope, definitely didn't drill the slides. The diaphragms are supple, uncracked, and in one piece as far as I can tell. Is there any way to check them besides visually and doing this?

June 17th, 2011, 06:48 PM	#18
kkim Join Date: Nov 2008 Posts: Too much.	nope... a visial is usually good. that's pretty ingenious in that vid. yes, please post what you find out with the clip positions.

June 18th, 2011, 11:23 AM	#19
AncientTV ninjette.org member Name: nah Location: nope Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250r Posts: 38	It's fixed! This was another case of The Previous Owner Curse So, while inspecting my slides for the millionth time, I decided to take a gander at the fiche for it. I happen to come across this little part: "Huh... wait a second." The previous owner had put 16007 and the needle in the wrong order (the head of the needle was resting on top, instead of enclosed on the bottom, and, being my unobservant self, I had kept putting it back in the same way Needless to say, that made most of my rev range about half an inch too rich on the needle. I flipped the parts into their correct spots, and now the bike rides like normal! The tuning is still off, but I can now do what I was supposed to be doing these last couple of months, and tune it to FP's instructions. Thanks for making me obsess about my slides kkim, I don't think I would've looked at the fiche otherwise, haha.

June 18th, 2011, 12:32 PM	#20
kkim Join Date: Nov 2008 Posts: Too much.	yay!!!