2008 250 voltage ?

racered · December 31st, 2021, 01:28 PM

The bike starts runs but the tach and fuel gauge power source,(brown wire), is not a steady voltage with engine running.Engine off the voltage is steady bat voltage 12.2. With a volt meter testing at gauge or fuse (taillight fuse) or any where on that circuit the voltage is sporadic, 14.2 to a brief drop to low voltage .05 then back to 14.2. The tach rises with rpm but not actual rpm, less than should be displayed, the fuel gauge shows less the it should as well. Applying bat voltage(14.2) to the circuit with engine running does not change the gauge readings. The alt is charging. The three fuses (tail head turn) which are on the same circuit all have the fluctuating voltage.The other circuits have steady voltage. All of the lighting has been removed, all interlocks are jumpered,there is only an ignition switch with key, run/stop switch, and starter button. The instrument panel is intact, oil and temp light function, when I unplug the panel the circuit voltage remains sporadic.
Want to weigh in?

Triple Jim · December 31st, 2021, 02:09 PM

Follow the wire that has non-steady voltage back toward the battery, checking it along the way. When you find steady voltage, you'll know where the bad connection is.

Then report back and we'll take the next step if necessary.

racered · December 31st, 2021, 07:43 PM

I built this bike from a "poor attempt" racer and a crashed "poor attempt" street racer. Flame away.

After exhaustive testing and no good result, I changed volt meter and the mysterious fluctuation was gone.

I added two gallons of fuel and the fuel gauge came up to almost half

I revved the motor up to a sweet scream while slapping the tach and saw 8000.

At idle the tach shows no movement but will show 1000 with slight throttle and a slap. Maybe a little love needed.
It was dark outside but the rain had stopped,and I wanted to give the bike a test run, so I eased er out and slipped it in gear, up the drive, onto the road. Couldn't see squat just a hint of road and dark ditch on either side.
Cold tires, wet road, ripped it up through fourth and let off, downshifted into a slight slide, got er stopped and turned around.
Ripped it back up to fourth, eased off a little more carefully and pulled into the shop.
It's like a comfy chair, needs more power.
Will start on the body work, fiberglass and paint.
Hope to take it to the track next week weather permitting and give er a good thrashing.

IMG_0004 (2).jpg

IMG_0007.jpg

IMG_0002 (2).jpg

shspvr · January 1st, 2022, 09:37 AM

Ops somebody installed the master link backwards and look like you need new sprocket to

racered · January 1st, 2022, 12:14 PM

There was half ass and stupid at every turn as I disassembled both machines.
The most glaring was the crashed bike. The main adjusting nut for the steering stem was absent.The forks were pro re-valved units, but whoever installed them I guess, did not know to install the spanner nut above the bearings to adjust preload, then install the top plate and bolt. The fork assembly was sloppy loose from loose neck bearings.
How does that happen? Who rides such a bike? One who crashes maybe.
The race bike had enough OMG to write paragraphs, but I would rather get back to work making a decent bike to play with.
Working for more horsepower and decent body work.
Looking forward to getting on the track.

racered · January 1st, 2022, 07:31 PM

Rode the bike today.The engine would pull to 7500 then start sputtering and losing power at WOT. Backing off the throttle and easing back into full throttle would bring a brief surge then sputtering and less power. Backing off from full throttle then holding about half throttle the engine pulled up to 9000, and no more, whether in fourth fifth or sixth gear, same deal.
Got back to the shop,pulled the plugs and they were clean NGK 6's.
Then pulled carbs, checked jet sizes and researched some tech forums for info.
The main jets in the carbs were 112. The needles were the stock item with one shim each.
What brand the jets are is unknown to me. I used my number drill set to measure the jet size and they both were #57 drill size.
I will add the carbs had K&N clamp on filters when I disassembled the bike.
I installed a factory air box when I reassembled the bike.
I have ordered a Factory Pro #1 carb jet kit. I will compare the jet sizes therein to the 112 jets and expect to be leaning the carbs a bit.
In the mean time fiberglass work will be the focus.
The track will have to wait a while.

shspvr · January 3rd, 2022, 03:00 AM

Quote:

Originally Posted by racered

Rode the bike today.The engine would pull to 7500 then start sputtering and losing power at WOT. Backing off the throttle and easing back into full throttle would bring a brief surge then sputtering and less power. Backing off from full throttle then holding about half throttle the engine pulled up to 9000, and no more, whether in fourth fifth or sixth gear, same deal.
Got back to the shop,pulled the plugs and they were clean NGK 6's.
Then pulled carbs, checked jet sizes and researched some tech forums for info.
The main jets in the carbs were 112. The needles were the stock item with one shim each.
What brand the jets are is unknown to me. I used my number drill set to measure the jet size and they both were #57 drill size.
I will add the carbs had K&N clamp on filters when I disassembled the bike.
I installed a factory air box when I reassembled the bike.
I have ordered a Factory Pro #1 carb jet kit. I will compare the jet sizes therein to the 112 jets and expect to be leaning the carbs a bit.
In the mean time fiberglass work will be the focus.
The track will have to wait a while.

fuel level low or need add one more shim to needle for top end power

DannoXYZ · January 3rd, 2022, 08:02 AM

shims/clips are for mid-range/partial-throttle

problem with not revving is due to clogged carbs or too much fuel in high end

bike is able to redline under WOT just fine when new off showroom floor. Restore everything to stock with stock airbox and stock jetting to make sure it runs like stock as baseline. Once it's able to redline like stock bike, then make incremental mods

best power is made with 94 or 96 mains on this bike (smaller than stock due to excessive richness from factory)

Post photos of FactoryPro needles when you get them in. Most likely they sent you kit for pre-gen models instead of new-gen. This will cause you endless frustration.

Also use proper plugs for this bike. NGK 6's are not the right ones.

racered · January 3rd, 2022, 01:12 PM

DannoXYZ, Thanks for the jetting chart and spark plug reference.
I did check the plugs after the second test run. They were new, dry and clean like the two on the right in your pic., and I did note the incorrect heat range at the time.
The bike has only been run at most 5 minutes on the road, the first trip was at night on wet pavement, cold tires and only for a short distance about 200 yards out then back. I was paying more attention to the feel of the bike and did not run the engine full throttle as conditions were too sketchy, However the next day I ran it about a half mile out then back.
Both trips the bike was warmed up in the shop then taken out for the run.
Prior to the test runs the bike was under the wrench for several days being disassembled then reassembled with race duty in mind.The tank was drained and inspected, the petcock checked for function and flow, the carbs disassembled and cleaned and yes they needed to be cleaned up from old fuel deposits clogging the idle and main circuits.I did not check spark plugs or valve lash.
On the first start up the bike idled and revved smoothly. It was warmed up to full temp then let cool for oil and filter change. I was impressed with how well the engine ran and sounded.
On the second test run I paid attention to throttle response from low to mid range then full throttle. From low to mid range at half throttle the engine ran well but opening the throttle further caused sputtering and misfire. I played with the throttle to repeat the symptoms and determine if it was a lean out or flooding or spark issue. I was not sure of either. I got back to the shop and pulled the plugs and they looked new and did not indicate a fat mixture but they had only run at full throttle for no more than 10 seconds or so. Most of their run time was at idle or revved to moderate rpm in the shop.
Then I pulled the carbs to see if there was anything I could do to fatten the mixture for a second test... I didn't have any shims for the needles so I drilled the 112 main jets one size larger, from #57 to #56,drill size, knowing I would be buying new jets.
The test drive after that change conclusively indicated I needed less fuel not more.

,and I expect and hope the stage one jet kit from Factory Pro will have stock size and maybe smaller,(and larger), that would be nice.
I don't know if the bike ever ran well with the 112 jets, that may explain the new incorrect spark plugs that were in it.
I will be checking valve lash before the next test drive and install #8 NGKs.
In the meanwhile I'm doing body work, and keeping the shop warm. Cheers

January 3rd, 2022, 08:02 AM	#8
DannoXYZ ninjette.org certified postwhore Name: AKA JacRyann Location: Mesa, AZ Join Date: Dec 2011 Motorcycle(s): CB125T CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR SFV650 VFR750F R1M ST1300PA Valkyrie-F6C Posts: A lot. MOTY - 2018, MOTM - Nov '17	shims/clips are for mid-range/partial-throttle problem with not revving is due to clogged carbs or too much fuel in high end bike is able to redline under WOT just fine when new off showroom floor. Restore everything to stock with stock airbox and stock jetting to make sure it runs like stock as baseline. Once it's able to redline like stock bike, then make incremental mods best power is made with 94 or 96 mains on this bike (smaller than stock due to excessive richness from factory) Post photos of FactoryPro needles when you get them in. Most likely they sent you kit for pre-gen models instead of new-gen. This will cause you endless frustration. Also use proper plugs for this bike. NGK 6's are not the right ones. Last futzed with by DannoXYZ; January 3rd, 2022 at 10:52 AM.
	1 out of 1 members found this post helpful.

December 31st, 2021, 01:28 PM	#1
racered ninjette.org member Name: paul Location: texas Join Date: Dec 2021 Motorcycle(s): not enough Posts: 33	2008 250 voltage ? The bike starts runs but the tach and fuel gauge power source,(brown wire), is not a steady voltage with engine running.Engine off the voltage is steady bat voltage 12.2. With a volt meter testing at gauge or fuse (taillight fuse) or any where on that circuit the voltage is sporadic, 14.2 to a brief drop to low voltage .05 then back to 14.2. The tach rises with rpm but not actual rpm, less than should be displayed, the fuel gauge shows less the it should as well. Applying bat voltage(14.2) to the circuit with engine running does not change the gauge readings. The alt is charging. The three fuses (tail head turn) which are on the same circuit all have the fluctuating voltage.The other circuits have steady voltage. All of the lighting has been removed, all interlocks are jumpered,there is only an ignition switch with key, run/stop switch, and starter button. The instrument panel is intact, oil and temp light function, when I unplug the panel the circuit voltage remains sporadic. Want to weigh in?

December 31st, 2021, 02:09 PM	#2
Triple Jim Guy Who Enjoys Riding Name: Jim Location: North Carolina Join Date: Jul 2016 Motorcycle(s): Ninja 250 Posts: A lot. MOTM - Oct '18, Aug '17, Aug '16	Follow the wire that has non-steady voltage back toward the battery, checking it along the way. When you find steady voltage, you'll know where the bad connection is. Then report back and we'll take the next step if necessary.

December 31st, 2021, 07:43 PM	#3
racered ninjette.org member Name: paul Location: texas Join Date: Dec 2021 Motorcycle(s): not enough Posts: 33	I built this bike from a "poor attempt" racer and a crashed "poor attempt" street racer. Flame away. After exhaustive testing and no good result, I changed volt meter and the mysterious fluctuation was gone. I added two gallons of fuel and the fuel gauge came up to almost half I revved the motor up to a sweet scream while slapping the tach and saw 8000. At idle the tach shows no movement but will show 1000 with slight throttle and a slap. Maybe a little love needed. It was dark outside but the rain had stopped,and I wanted to give the bike a test run, so I eased er out and slipped it in gear, up the drive, onto the road. Couldn't see squat just a hint of road and dark ditch on either side. Cold tires, wet road, ripped it up through fourth and let off, downshifted into a slight slide, got er stopped and turned around. Ripped it back up to fourth, eased off a little more carefully and pulled into the shop. It's like a comfy chair, needs more power. Will start on the body work, fiberglass and paint. Hope to take it to the track next week weather permitting and give er a good thrashing. IMG_0004 (2).jpg IMG_0007.jpg IMG_0002 (2).jpg

January 1st, 2022, 09:37 AM	#4
shspvr ninjette.org guru Name: Anthony Location: Vinita, Ok Join Date: Sep 2021 Motorcycle(s): 07 Kawasaki Ninja 250 Posts: 343	Ops somebody installed the master link backwards and look like you need new sprocket to

January 1st, 2022, 12:14 PM	#5
racered ninjette.org member Name: paul Location: texas Join Date: Dec 2021 Motorcycle(s): not enough Posts: 33	There was half ass and stupid at every turn as I disassembled both machines. The most glaring was the crashed bike. The main adjusting nut for the steering stem was absent.The forks were pro re-valved units, but whoever installed them I guess, did not know to install the spanner nut above the bearings to adjust preload, then install the top plate and bolt. The fork assembly was sloppy loose from loose neck bearings. How does that happen? Who rides such a bike? One who crashes maybe. The race bike had enough OMG to write paragraphs, but I would rather get back to work making a decent bike to play with. Working for more horsepower and decent body work. Looking forward to getting on the track.

January 1st, 2022, 07:31 PM	#6
racered ninjette.org member Name: paul Location: texas Join Date: Dec 2021 Motorcycle(s): not enough Posts: 33	Rode the bike today.The engine would pull to 7500 then start sputtering and losing power at WOT. Backing off the throttle and easing back into full throttle would bring a brief surge then sputtering and less power. Backing off from full throttle then holding about half throttle the engine pulled up to 9000, and no more, whether in fourth fifth or sixth gear, same deal. Got back to the shop,pulled the plugs and they were clean NGK 6's. Then pulled carbs, checked jet sizes and researched some tech forums for info. The main jets in the carbs were 112. The needles were the stock item with one shim each. What brand the jets are is unknown to me. I used my number drill set to measure the jet size and they both were #57 drill size. I will add the carbs had K&N clamp on filters when I disassembled the bike. I installed a factory air box when I reassembled the bike. I have ordered a Factory Pro #1 carb jet kit. I will compare the jet sizes therein to the 112 jets and expect to be leaning the carbs a bit. In the mean time fiberglass work will be the focus. The track will have to wait a while.

January 3rd, 2022, 01:12 PM	#9
racered ninjette.org member Name: paul Location: texas Join Date: Dec 2021 Motorcycle(s): not enough Posts: 33	DannoXYZ, Thanks for the jetting chart and spark plug reference. I did check the plugs after the second test run. They were new, dry and clean like the two on the right in your pic., and I did note the incorrect heat range at the time. The bike has only been run at most 5 minutes on the road, the first trip was at night on wet pavement, cold tires and only for a short distance about 200 yards out then back. I was paying more attention to the feel of the bike and did not run the engine full throttle as conditions were too sketchy, However the next day I ran it about a half mile out then back. Both trips the bike was warmed up in the shop then taken out for the run. Prior to the test runs the bike was under the wrench for several days being disassembled then reassembled with race duty in mind.The tank was drained and inspected, the petcock checked for function and flow, the carbs disassembled and cleaned and yes they needed to be cleaned up from old fuel deposits clogging the idle and main circuits.I did not check spark plugs or valve lash. On the first start up the bike idled and revved smoothly. It was warmed up to full temp then let cool for oil and filter change. I was impressed with how well the engine ran and sounded. On the second test run I paid attention to throttle response from low to mid range then full throttle. From low to mid range at half throttle the engine ran well but opening the throttle further caused sputtering and misfire. I played with the throttle to repeat the symptoms and determine if it was a lean out or flooding or spark issue. I was not sure of either. I got back to the shop and pulled the plugs and they looked new and did not indicate a fat mixture but they had only run at full throttle for no more than 10 seconds or so. Most of their run time was at idle or revved to moderate rpm in the shop. Then I pulled the carbs to see if there was anything I could do to fatten the mixture for a second test... I didn't have any shims for the needles so I drilled the 112 main jets one size larger, from #57 to #56,drill size, knowing I would be buying new jets. The test drive after that change conclusively indicated I needed less fuel not more. ,and I expect and hope the stage one jet kit from Factory Pro will have stock size and maybe smaller,(and larger), that would be nice. I don't know if the bike ever ran well with the 112 jets, that may explain the new incorrect spark plugs that were in it. I will be checking valve lash before the next test drive and install #8 NGKs. In the meanwhile I'm doing body work, and keeping the shop warm. Cheers