What acceleration? carbs cleaned

[MrSavvy]

Alright so I've been having acceleration issues lately. I have a '09 250r.
Bought the bike with 7k miles, sitting right at 9k now. Oil change was done right before I bought it.
Last fall at ~8k miles, the acceleration would bog down at times. I'd give her some gas from a stop and she would almost stall out. Only happened once or twice over the course of fall/early winter.

Well I didn't ride her for a month or two, during the coldest days of winter. I didn't winterize her because I planned on riding once a week to keep the carbs clear.
Of course, I didn't.

Of course, last week I go to take her for a ride and she won't even idle hardly. Kind of expected that.

I stripped her down to the carbs, using this DIY. Went the Pine-sol route. Yea, not so good... after 4 days there was this white crusty s*** on the metal, and even stripped some of the protective coating off. Even looked like some lime build-up on parts of the carbs.

My buddy used to race quads and he said they always soaked the carbs in gasoline, so I did that for 24hrs and then cleaned the carbs off with a tooth brush.

Re-installed the jets (carefully), re-assembled, put everything back on the bike except the fairings... poured fresh fuel into the tank (I had siphoned the old fuel out) and added a couple ounces of sea foam.

Idles great now. Sounds like she wants to cut off at ~800rpm's, so I set her to idle at 1.1k rpm's or so. Well after warming up for 4+ mins, I geared up and was going to take her around the apt for a test drive.
She gets up to 5k rpm's and then bogs down and almost cuts off. If I put her in 1st and try to accelerate, it's even worse. Instantly dies almost.
If I let off the throttle quickly, she doesn't cut off, just drops down to 500rpm's and climbs back up to idle.

This might sound retarded, but if I rock the 250 side-to-side, I can reach a higher rpm? Maybe say, 8k instead of 5k, without bogging/dying?

I have changed the plugs to NGK's, #CR8HSA. Gapped appropriately.
I will say the old plugs I removed had black tips. I'm talking crispy black, not "hey that's a little dark" lol (Indicative of rich fuel?)

I did remove the idle screw plugs so I can adjust the idle mixture.

I do not know when the fuel and air filters were replaced.


TL;DR: Idles fine, bogs down/won't accelerate, new and gapped spark plugs. Any ideas?

[Bones85]

NGK CR8HSA is for pre-gen Ninja 250's (88-07).

Newgen models use NGK CR8E or NGK CR8EIX.

[MrSavvy]

Originally Posted by Bones85

NGK CR8HSA is for pre-gen Ninja 250's.

You want NGK CR8E or NGK CR8EIX.

Damn

[Bones85]

I'm not sure if that's what causing your problems though. Hopefully someone with more knowledge can give their input.

[MrSavvy]

Originally Posted by Bones85

I'm not sure if that's what causing your problems though. Hopefully someone with more knowledge can give their input.

Yea, I appreciate the input though. First time doing any maintenance on a motorcycle.

[Motofool]

Originally Posted by MrSavvy

.....This might sound retarded, but if I rock the 250 side-to-side, I can reach a higher rpm? Maybe say, 8k instead of 5k, without bogging/dying?......
[/B]

I would check the entire supply system, from the tank to the interior of the bowls.
Any restriction to the flow of gasoline that messes the specified level inside the bowls could cause this problem.
Rocking the bike may increase that supply flow somehow.

Also the entire air intake system for any restriction.

Did you note the condition of the carbs' diaphragms?

[MrSavvy]

Originally Posted by Motofool

I would check the entire supply system, from the tank to the interior of the bowls.
Any restriction to the flow of gasoline that messes the specified level inside the bowls could cause this problem.
Rocking the bike may increase that supply flow somehow.

Also the entire air intake system for any restriction.

Did you note the condition of the carbs' diaphragms?

Alright I'll do a thorough investigation tomorrow. Any tips on the process? All I can think of would be to check gas flow through the hoses and such.
I will say, I didn't clean the jets really. I unscrewed the jets, and soaked them with the carbs. But didn't air blast them out or stick anything through the inside of the jets.

And yes, the diaphragms were completely fine. No nicks, scratches, irregular shaping, etc. Actually, I didn't even find any gunk or dirty gasoline during the carb cleaning process.

This might be my first time tearing down part of a street bike engine, but I've done everything from turbo swaps and head gasket replacements to full suspension on my VW. I enjoy this kind of stuff.

[Motofool]

Originally Posted by MrSavvy

Alright I'll do a thorough investigation tomorrow. Any tips on the process?......

Sorry, I don't have specific tips, since I am not familiar with the new-gens'.

In general, you should see a flow of about 2 c.c. per second with vacuum applied to the petcock.

Now, even if good flow is found, sticky float valves could cause limited or zero flow.
For that reason, a second good step would be measuring the level that the fuel reaches inside each bowl when the engine is working.

If the diaphragms are fine, they should move the needle up and down as you open and close the throttle.

It is not uncommon to find some rag restricting the air intake at the air box.

[DaBlue1]

Originally Posted by MrSavvy

... after 4 days there was this white crusty s*** on the metal, and even stripped some of the protective coating off. Even looked like some lime build-up on parts of the carbs.

Originally Posted by MrSavvy

....I will say, I didn't clean the jets really. I unscrewed the jets, and soaked them with the carbs. But didn't air blast them out or stick anything through the inside of the jets.

You may want to do just that. Soaking alone will not remove any clogs from the tiny tiny holes on the jets.

[MrSavvy]

Alright I started working on my 250 this morning. Just finished pulling the carbs out again. This time I removed every jet and idle mix piece. Blasted out the insides of the jets, and where the jets sit, with carb cleaner. Ran a single strand from a 16g wire through each jet. I found some gunk on the tips of the idle mixture screws. Cleaned that off really well.

Put everything back together. Put the new fuel in with the sea foam. Set the petcock to PRI and started her up. Switched the petcock to ON after 20secs or so. Idling decently.

Let her warm up for a good 5 mins. I was able to rev her up to 9k rpm's with a little coaxing, although she didn't like it. Attempted to ride around my apt area, still a no go. Bogs down and almost dies when I let the clutch out in 1st.
I'm keeping the choke on full, until she can accelerate without dying.

I checked all the lines from the petcock to the carbs, all the lines running around the carbs. No blockages or anything.

Edit: Here's my uneducated thoughts; Maybe it's running too rich right now? Almost seems like when I give it some throttle, it floods out. Idk. I'm going to try and tighten the idle mix screws, see if that helps.

[MrSavvy]

Yea I got nothin. Didn't affect it at all. The idle mixture screws are sitting at 1 1/2 turns. Previously 2 1/2 turns. I'd say it's idling worse on 1 1/2.

Random thought, could a dented gas tank effect the performance of the bike at all?

Edit: Update # a million: I sprayed one very small spray of starter fluid onto the tip of the snorkel. She jerkily but rapidly jumped up to 7k rpm's. The bike idles at around 3k rpm's with full choke, but should be at 7k.
If the bike runs better, or even how it should, when I spray starter fluid; isn't that indicative of running too lean?

Edit2: Oh and I check the air box. There were a couple small leaves on the intake-side of the airbox, cleaned them out. Nothing got past the filter. Snorkel is clear.

Edit3: I'm going to pick up a set of CR8EIX plugs, NGK not that Autolite crap lol. What should they be gapped to? I can't find any info online. And the previous owner didn't give me the manual for the bike.

[Bones85]

Originally Posted by MrSavvy

I'm going to pick up a set of CR8EIX plugs, NGK not that Autolite crap lol. What should they be gapped to? I can't find any info online. And the previous owner didn't give me the manual for the bike.

0.7 ∼ 0.8 mm (0.028 ∼ 0.031 in.)

[MrSavvy]

She won't even idle now. Dies right after ignition. I re-set the mixture screws to 2 1/2 turns. Put in the CR8EIX's gapped to ~.75 mm. Even worse than before. Could it be I don't have enough gas in the tank? It's probably around 1.5 gal of fresh fuel.

[DaBlue1]

Originally Posted by MrSavvy

....Random thought, could a dented gas tank effect the performance of the bike at all?

It should not. However if the dent has formed a good amount of rust on the inside of the tank, the rust could clog the petcock and inline filter.

Originally Posted by MrSavvy

.... The bike idles at around 3k rpm's with full choke, but should be at 7k.

3k is the average high idle speed for a cold engine with full choke. As the engine gets warmer it may increase.


What is your idle speed set to? You made need to up it a little bit (by using the adjustment knob) to get it steady. Idle speed is 1300 +/- 50 rpms when fully warmed.

[MrSavvy]

Originally Posted by DaBlue1

It should not. However if the dent has formed a good amount of rust on the inside of the tank, the rust could clog the petcock and inline filter.

Originally Posted by MrSavvy

.... The bike idles at around 3k rpm's with full choke, but should be at 7k.

3k is the average high idle speed for a cold engine with full choke. As the engine gets warmer it may increase.

What is your idle speed set to? You made need to up it a little bit (by using the adjustment knob) to get it steady. Idle speed is 1300 +/- 50 rpms when fully warmed.

Currently I have the knob all the way out (where it's just barely touching the "throttle bracket lever"). I have attempted starting it while increasing the knob in increments.
I'm not sure what else it could be. I've tried everything. And now it's worse than when I started. It won't even fire up. I have the starter running and she turns over when I turn the ignition. Just no combustion. Maybe try a ~.5mm smaller gap?
Might be time for a trip to a local dealer or shop (Street and Trail, etc...)

Edit: oh, and the extremely-fine mesh filter on the petcock is in good condition. It doesn't have any holes, rips, or discoloration. It's still a nice gas-colored yellow/white. Maybe I should still check the inline filter though...

[DaBlue1]

Originally Posted by MrSavvy

...Currently I have the knob all the way out (where it's just barely touching the "throttle bracket lever"). I have attempted starting it while increasing the knob in increments.

Turning the knob to the right increases the idle speed. Start with it turned almost all the way in, then back it out.

[kirk595x]

Getting higher RPMs while rocking makes me think its your floats. They could have come out of adjustment during diassembly.

[MrSavvy]

Originally Posted by DaBlue1

Turning the knob to the right increases the idle speed. Start with it turned almost all the way in, then back it out.

That's what I was doing, but thanks. I just started with it all the way out and started increasing the idle. I'll give your way a shot though.

Originally Posted by kirk595x

Getting higher RPMs while rocking makes me think its your floats. They could have come out of adjustment during diassembly.

You know, that crossed my mind. Also, after the second dissassembly the problem worsened. And on the 2nd time around, I removed both floats to check the fuel needle tips (which were fine).

I'll go pull the carbs back out (again lol) and check the floats in each carb. Is there a specific way to adjust them? From what I remember, it's just the fuel needle>float>rod holding float in place.

Also, I think it might be worth adding 2 washers to each of the diaphragm needles?

[MrSavvy]

Ok as my final update for the day...

Possible causes to my situation?:
1) Bike was in an accident, bent front forks and laid over going >15mph. Replaced forks/fork oil/dust caps/etc.
2) Bike sat half the winter uncovered, including several rain storms.
3) Battery died today while attempting to start the 250 up.

^Could any of those cause the bad idle/dying on acceleration issues I'm having?

I jumped the bike off with my car (while car was off, of course). I am able to get my 250 to stay on for aprox 2 seconds now. Every crank, about 1-4 seconds of ~300rpm idling then she dies.

And that's where I am currently. Not sure what to do next.

Last thought... when removing the carbs the second time, I noticed there was liquid in the left "carb shute" (no idea what that's called lol), the hole where the left carb connects to the engine via a rubber dual-clamp sleeve. 95% sure it was gasoline. The right-side sleeve was dry. Is that indicative of anything bad?
And on the most recent carb removal, when I drained the bowls I put the gas into a 20oz for examination. The gas was sitting in the bottom half of 20oz, and there was a lighter clear colored liquid on the top half. I shook the bottle up and it separated from the gas completely in less than 15 seconds. Was that seafoam? Or something else...

[Motofool]

Originally Posted by MrSavvy

..........I'll go pull the carbs back out (again lol) and check the floats in each carb.......

Also, I think it might be worth adding 2 washers to each of the diaphragm needles?

Don't need to pull the carbs back out.

Don't add washers now.

Did you check gas flow and needles movement with vacuum applied?

Originally Posted by Motofool

In general, you should see a flow of about 2 c.c. per second with vacuum applied to the petcock.

Now, even if good flow is found, sticky float valves could cause limited or zero flow.
For that reason, a second good step would be measuring the level that the fuel reaches inside each bowl when the engine is working.

If the diaphragms are fine, they should move the needle up and down as you open and close the throttle.

[MrSavvy]

Originally Posted by Motofool

Don't need to pull the carbs back out.

Don't add washers now.

Did you check gas flow and needles movement with vacuum applied?

I can un-shim the carbs if needed, I had already added the washers before my last post (1min before your post).

I didn't check the vac yet, no. Wasn't sure how to. I'll check it tomorrow. If the vac is lower than it should be, does that signify a sticking float valve?

[Motofool]

No, if you added the shims, just leave them in place, nothing dramatic will happen,...sorry for posting late.

What I mean with applied vacuum is that the petcock only let gas flow down when there is vacuum applied to it via the vacuum tube in its back.

The diaphragms also work by the vacuum that they feel at the throttle of the carbs, lifting the needles and open the path to more fuel when that vacuum increases.

Hope you can solve this mystery soon

[DaBlue1]

Originally Posted by MrSavvy

....3) Battery died today while attempting to start the 250 up.

^Could any of those cause the bad idle/dying on acceleration issues I'm having?

I jumped the bike off with my car (while car was off, of course). I am able to get my 250 to stay on for aprox 2 seconds now. Every crank, about 1-4 seconds of ~300rpm idling then she dies.

Here are the classic symptoms of battery failure. If any of these are present, test the battery as outlined below.

-Gauges on (neutral, oil and temp) but the starter won't catch
-Tach starts bouncing, and then the engine starts to act like it's out of gas.
-Engine keeps coughing, but tach is much higher than it should be, or it is bouncing wildly from low to high.
~excerpt from http://faq.ninja250.org wiki/How_to_tell_if_your_battery_is_dead

[MrSavvy]

Originally Posted by Motofool

No, if you added the shims, just leave them in place, nothing dramatic will happen,...sorry for posting late.

What I mean with applied vacuum is that the petcock only let gas flow down when there is vacuum applied to it via the vacuum tube in its back.

The diaphragms also work by the vacuum that they feel at the throttle of the carbs, lifting the needles and open the path to more fuel when that vacuum increases.

Hope you can solve this mystery soon

It's all good.

Today I rigged up a carb sync tool. Two glass bottles, rubber stoppers with holes drilled, and tubing. I got the carbs as synced as they'll be cold and not idling for long.

Also, I disconnected the hose from the gas tank to the carb and stuck the hose into a clear container. The petcock was allowing fuel through when vacuum was applied. So I know the petcock is functioning.

I'll have the $ to pick up a Fuel Level Gauge this Thursday. Guess I can't do much until then.

The one thing that perplexes me; why does the 250 run as long as I want it to, and reach instant rpm's up to redline with a twist of the throttle, as long as I give it little spritzes of starter fluid every 5 seconds?

Edit: I never actually ran any wire through the pilot circuits. Only the jets. And I really don't like the effect the pine-sol had on the exterior metal of the carbs. It might have left residual sh** on the circuits and inner workings of the carbs as well.
I'm going to take the carbs out one last time, completely dismantle them, buy some actual high-quality carb cleaner, and go to town on them. I'll also change the oil and oil filter, needs to be done soon anyway. I'll update you guys this Saturday or Sunday. Thanks for all the help so far!

[kirk595x]

I've had luck with soaking carbs in a combo of Seafoam and Carb cleaner then boiling in water for a few minutes and finish up with blowing out every passage with compressed air. Fine wire can be used to chase some passages and jets. I've only come across one Carb I could not bring back from the dead with these techniques but it was chinese so nuff ssid.

[ninja250r81]

buy some 2nd hand carbs.

check electrical connections