Tuning help

scotty · January 26th, 2011, 11:57 AM

Heres my set up:

Full exhaust
Pod filter
Kleen Air removed
110 Mains
3rd clip on needles
2.5 turns out on mixture screws

The bike runs great with that set up. Starts up from being cold with the choke, warms up in about ten min, and idels at 1800rpm.

I rode like that last summer, but I grew tired of the loud exhaust. So after thinking about it for a few weeks, I went ahead and took the full exhust off and replaced it with the OEM exhaust.

Once I got the OEM one installed, I went to start the bike up. To say the least, it was hell getting it running. The choke wouldn't even do anything.(sit at 300rpm, then die) I manged to get it running with out the choke. Although I had to used th throttle to help it. After about 1-2 min useing the throttle I manged to get the choke to keep it running.( At about 3k). I had to mess with the idle a bit. Once it was warmed up I got it to idle at 1500 rpm. It runs okay. Has a hesitation between 4-5 rpm. When you rev it up, you can also see a little smoke. I'm sure it's due to it being rich now. With the bike warmed up, it will start up no problem.

I was thinking I should back off the mixture screws a tad bit.?. Anyone agree with this? Any sujestions with the crappy start up? Thanks for any help!

setasai · January 26th, 2011, 06:42 PM

If you restored the OEM exhaust, I would think it'd be in your best interest to rejet it from the beginning, no? Limiting the exhaust should in essence richen the whole powerband. Atleast to my understanding.

On the other hand, what's wrong with the full exhaust? I understand the loudness thing but maybe try better earplugs instead? It's your bike so do whatever you like but I just figured that if you worked that hard to get it running with the exhaust in and the responsiveness is where you want it. I'd just go out and ride more with better earplugs than mess with going back to a more restrictive exhaust system.

scotty · January 26th, 2011, 06:45 PM

Thats what I think with it being more rich now. I wonder if I should go down to 108's main jets from the 110's installed right now. I think I will adjust the mixture screws tomorow when I see the bike again.

Can the bike running very rich cause the start up issue while using the choke? I checked the cable to be sure it was doing it's job. (It was okay)

setasai · January 26th, 2011, 06:51 PM

I would think so. If it's already rich, adding the choke on will literally "choke" the engine since there isnt enough air to sustain the combustion. Regardless, if the ratio isnt close enough to ideal, you'll have difficulty getting the engine running.

scotty · January 26th, 2011, 06:52 PM

Quote:

Originally Posted by setasai

I would think so. If it's already rich, adding the choke on will literally "choke" the engine since there isnt enough air to sustain the combustion. Regardless, if the ratio isnt close enough to ideal, you'll have difficulty getting the engine running.

Cool, thanks! You made it make sence to me!

I will mess with it and report back!

kkim · January 26th, 2011, 09:48 PM

try adjusting the mixtures screws... I'm pretty sure that will help. after you get it running better at start up, you'll need to work on jetting again from the top on back down.

BTW, the choke system on out bikes is really a enriching device that provides more fuel, not less air like the traditional "choke", so if your bike is overly rich already, using the choke will really make things too rich for a smooth running startup.

I don't think there's anyone else with a pod setup and stock exhaust, so you might be charting new territory. if there is someone else, hopefully they'll chime in with their jetting setup.

keep good notes so when you go back to a full exhaust you'll remember where you had everything set.

scotty · January 26th, 2011, 10:27 PM

I know JMcDonald had a pod set up with the OEM exhaust at one point, but he never got it running right.

I will keep notes, and when I get the bike running perfect again I shall share what I did for other people who may want to go this rout. IMO, the bike sounds great with the OEM exhaust and pod filter. I'm going to try to work in it tomorow, but may have to wait to the weekend. Hate not having my own garage!

setasai · January 27th, 2011, 03:18 AM

Quote:

Originally Posted by kkim

BTW, the choke system on out bikes is really a enriching device that provides more fuel, not less air like the traditional "choke", so if your bike is overly rich already, using the choke will really make things too rich for a smooth running startup.

Thanks for the clarification. Didnt know our bikes worked differently.

In anycase, the usual rejet and report.

HKr1 · January 27th, 2011, 04:16 PM

Does kinda sound like an odd problem. I take it your pilots are stock? I can see the top end being rich... But, you have to think. Everybody with an airbox is running stock pilots and 2.5 to 3 out on the mixture. Now you take out the airbox for pods, I would think it would be leaner on the bottom

Maybe its too lean on the bottom to over come the back pressure? Still seems like the choke would do something.... I know swapping from the stock muff to a gutted one, it still starts the same. But were still running the airbox.

scotty · January 27th, 2011, 06:30 PM

Quote:

Originally Posted by HKr1

Does kinda sound like an odd problem. I take it your pilots are stock? I can see the top end being rich... But, you have to think. Everybody with an airbox is running stock pilots and 2.5 to 3 out on the mixture. Now you take out the airbox for pods, I would think it would be leaner on the bottom

Maybe its too lean on the bottom to over come the back pressure? Still seems like the choke would do something.... I know swapping from the stock muff to a gutted one, it still starts the same. But were still running the airbox.

The pilots are a whole other issue... but yes, they are the oem 38's. I have 110 main jets with the mixture screws out 2.5 turns. I think Im going to try to bring them in with a total of 2 turns out and see if it will start if not, go to 1.5 turns out, ect.

Unfortunately, I haven't been able to mess with the bike today.

I don't think I will be able to, till next week. Life is a little nutty this week.

kkim · January 27th, 2011, 10:28 PM

to set the mixture screws... http://faq.ninja250.org/wiki/How_do_...dle_mixture%3F

January 26th, 2011, 11:57 AM	#1
scotty ninjette.org certified postwhore Name: Scott Location: Carlise Ohio Join Date: Apr 2010 Motorcycle(s): Yahama v star 650 classic Posts: A lot.	Tuning help Heres my set up: Full exhaust Pod filter Kleen Air removed 110 Mains 3rd clip on needles 2.5 turns out on mixture screws The bike runs great with that set up. Starts up from being cold with the choke, warms up in about ten min, and idels at 1800rpm. I rode like that last summer, but I grew tired of the loud exhaust. So after thinking about it for a few weeks, I went ahead and took the full exhust off and replaced it with the OEM exhaust. Once I got the OEM one installed, I went to start the bike up. To say the least, it was hell getting it running. The choke wouldn't even do anything.(sit at 300rpm, then die) I manged to get it running with out the choke. Although I had to used th throttle to help it. After about 1-2 min useing the throttle I manged to get the choke to keep it running.( At about 3k). I had to mess with the idle a bit. Once it was warmed up I got it to idle at 1500 rpm. It runs okay. Has a hesitation between 4-5 rpm. When you rev it up, you can also see a little smoke. I'm sure it's due to it being rich now. With the bike warmed up, it will start up no problem. I was thinking I should back off the mixture screws a tad bit.?. Anyone agree with this? Any sujestions with the crappy start up? Thanks for any help! __________________________________________________

January 26th, 2011, 06:42 PM	#2
setasai ninjette.org certified postwhore Name: Brian Location: Detroit, MI Join Date: Jun 2010 Motorcycle(s): 2009 Ninja 250R Green Posts: A lot.	If you restored the OEM exhaust, I would think it'd be in your best interest to rejet it from the beginning, no? Limiting the exhaust should in essence richen the whole powerband. Atleast to my understanding. On the other hand, what's wrong with the full exhaust? I understand the loudness thing but maybe try better earplugs instead? It's your bike so do whatever you like but I just figured that if you worked that hard to get it running with the exhaust in and the responsiveness is where you want it. I'd just go out and ride more with better earplugs than mess with going back to a more restrictive exhaust system. Last futzed with by setasai; January 26th, 2011 at 06:44 PM. Reason: more thoughts.

January 26th, 2011, 06:45 PM	#3
scotty ninjette.org certified postwhore Name: Scott Location: Carlise Ohio Join Date: Apr 2010 Motorcycle(s): Yahama v star 650 classic Posts: A lot.	Thats what I think with it being more rich now. I wonder if I should go down to 108's main jets from the 110's installed right now. I think I will adjust the mixture screws tomorow when I see the bike again. Can the bike running very rich cause the start up issue while using the choke? I checked the cable to be sure it was doing it's job. (It was okay) __________________________________________________

January 26th, 2011, 10:27 PM	#7
scotty ninjette.org certified postwhore Name: Scott Location: Carlise Ohio Join Date: Apr 2010 Motorcycle(s): Yahama v star 650 classic Posts: A lot.	I know JMcDonald had a pod set up with the OEM exhaust at one point, but he never got it running right. I will keep notes, and when I get the bike running perfect again I shall share what I did for other people who may want to go this rout. IMO, the bike sounds great with the OEM exhaust and pod filter. I'm going to try to work in it tomorow, but may have to wait to the weekend. Hate not having my own garage! __________________________________________________

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January 26th, 2011, 06:51 PM	#4
setasai ninjette.org certified postwhore Name: Brian Location: Detroit, MI Join Date: Jun 2010 Motorcycle(s): 2009 Ninja 250R Green Posts: A lot.	I would think so. If it's already rich, adding the choke on will literally "choke" the engine since there isnt enough air to sustain the combustion. Regardless, if the ratio isnt close enough to ideal, you'll have difficulty getting the engine running.

January 26th, 2011, 09:48 PM	#6
kkim Join Date: Nov 2008 Posts: Too much.	try adjusting the mixtures screws... I'm pretty sure that will help. after you get it running better at start up, you'll need to work on jetting again from the top on back down. BTW, the choke system on out bikes is really a enriching device that provides more fuel, not less air like the traditional "choke", so if your bike is overly rich already, using the choke will really make things too rich for a smooth running startup. I don't think there's anyone else with a pod setup and stock exhaust, so you might be charting new territory. if there is someone else, hopefully they'll chime in with their jetting setup. keep good notes so when you go back to a full exhaust you'll remember where you had everything set.

January 27th, 2011, 04:16 PM	#9
HKr1 IC2(SW) Name: Kerry Location: Pensacola Join Date: Nov 2008 Motorcycle(s): . Posts: A lot.	Does kinda sound like an odd problem. I take it your pilots are stock? I can see the top end being rich... But, you have to think. Everybody with an airbox is running stock pilots and 2.5 to 3 out on the mixture. Now you take out the airbox for pods, I would think it would be leaner on the bottom Maybe its too lean on the bottom to over come the back pressure? Still seems like the choke would do something.... I know swapping from the stock muff to a gutted one, it still starts the same. But were still running the airbox.

January 27th, 2011, 10:28 PM	#11
kkim Join Date: Nov 2008 Posts: Too much.	to set the mixture screws... http://faq.ninja250.org/wiki/How_do_...dle_mixture%3F