Issues... Electrical? Fuel?

[ithaca00]

I pulled my 2008 Ninja 250 race bike out of storage for this year's AFM season and a major problem has presented itself. At seemingly random times the bike will stop revving freely. It'll stop at 9k or 6k rpm no matter what gear I'm in and not go past that. Then, again out of nowhere, it'll come back to life and be a wonderful little bike again. The only potential pattern that I can see is maybe happening on hard acceleration (race starts, high RPM gear changes) but it's random enough that I can't pin anything exactly.

I thought it was the aftermarket ignition module so I put that back to stock. Nope.

I found the negative battery cable screw loose. Not the solution.

I put the aftermarket ignition back in. Same problem.

The connections are fine on the coils.

I'm really at a loss and this has happened in two races now and dramatically affected both. Any thoughts?

Slight update after typing this (is it really an update if I haven't posted it here yet?)

I just went to take the tank off, pulled off the fuel line to the carb and nothing came out. I found the stock fuel filter crumpled and wedged into the fuel line. I yanked that out and a bit of fuel came out.

Does this help at all? I'm thinking this might be the cause but it's an expensive process to do a trackday then still have the issue present itself...

[Motofool]

Originally Posted by ithaca00

....... Does this help at all? I'm thinking this might be the cause but it's an expensive process to do a trackday then still have the issue present itself...

It seems to be an obstruction that can move (hence the randomness) inside the air passages or inside the fuel supply plumbing.

[ithaca00]

There have been two updates so far on this.

I was taking the tank off and found the inline fuel filter crumpled in the line (this is after yanking it out so it's straightened out a bit):


Second, I removed the plugs and found them like this:


The fuel filter might be the cause of it but it still seems odd. I doubt the plug is anything more than unsightly. I'm trying to check the coils, though I think I'm doing it incorrectly. I can't think of anything else.

The fact that the issue only happens at high RPMs coupled with the fact that it's a race bike and I can't take it out on the street is very frustrating...

[Motofool]

Originally Posted by ithaca00

........... Second, I removed the plugs and found them like this:
..........

[ithaca00]

Yeah, I'm not sure what happened to the #2 plug. Maybe gas got in the well after I crashed in the last race?

[Motofool]

Originally Posted by ithaca00

Yeah, I'm not sure what happened to the #2 plug. Maybe gas got in the well after I crashed in the last race?

Gas does not do that, water does.

It may be a combination of both things, the filter and intermittent failure of sparks from that plug at high rpm's.

If there was a bridge to the high voltage due to contamination of the well and boot, the sparks may have been able to jump inside the chamber for low rpm's but not for high rpm's/high pressure conditions.

[ithaca00]

Hmmm... Maybe. I don't know enough to make any real conclusions. :/

Would that still explain the very inconsistent nature of it. I could run the track for a few sessions with no issue then randomly it would happen and stay like that. I'm not sure why it would even correct itself and there was no pattern.

[Motofool]

Originally Posted by ithaca00

.......... Would that still explain the very inconsistent nature of it. I could run the track for a few sessions with no issue then randomly it would happen and stay like that. I'm not sure why it would even correct itself and there was no pattern.

Hard to say, but that is exactly the way in which most electrical problems behave.

Your best line of action may be checking all the points that can randomly become a bottle neck for the flow of fuel and electricity (filters, connectors, switches).

Did you inspect the air path?

[ithaca00]

Air path is good. The carbs were just cleaned a few weeks ago, cleaned filter and cleaned air box.

Now that you mention it I did have another electrical issue that is completely NOT related but who knows. I removed the kickstand and shorted out the safety switch with a vampire tap. That came loose at the last trackday but stopped the bike completely. I redid the tap and all was well again.

I can think of several paths if the bike didn't start, died completely while riding, exhibited this issue all of the time. But the randomness of it makes it extremely confusing.

[ithaca00]

I took it out to a track day on Monday and crossed my fingers. On my out lap the bike had no power and I made it two laps before pulling in to the pits. My top speed was ~80mph at the end of the front straight but I was still passing people on bigger bikes in B group

I had adjusted the needles on the carbs before this so I put those back to the prior position. In the process I found the band clamp on a carb-engine boot was loose. I tightened that back up and all was right in the world. I made it the rest of the day without any issues Hyper

As a recap, I removed the crumpled fuel filter and a corroded spark plug.

Fingers are crossed that this holds up...

[jkv45]

What's the situation with the fuel? Have you drained the floatbowls? How about completely draining the tank and refilling?

What gas are you running?

If there's any questionable gas in the tank I would drain it before digging in too deep.

[ithaca00]

The gas is good.

The first tank was 91 from an Arco and my friend filled up his bike and car at the same time. The second tank was 87 from Valero, again, car and second bike filled up at the same time. Next was ~1/2 tank of 100 from the race track. This last tank was 91, and again, second bike and car were filled at the same time.

[jkv45]

Have you drained the floatbowls and looked at what came out?

Is the tank completely clean inside?

Have you had the carbs off?

Assuming you are trying to get the most out of the Ninja, run 87 octane without ethanol for the most power with a stock engine. Excess octane, over what is needed to just barely keep it from detonating, reduces power.

[cadd]

He stated the carbs were cleaned a few weeks ago.

[jkv45]

Originally Posted by cadd

He stated the carbs were cleaned a few weeks ago.

Thanks - must have missed that.

[ithaca00]

Yup, carbs were cleaned at the beginning of the season.

I run higher octane because of my BRT TiS ignition module. The base map calls for 91 octane and the secondary map calls for 100 octane fuel. At least that's what I was told by the rep a few years back. When I mentioned the different fuel grades I was trying to isolate the ignition module as the source, or not, hence the change from 91-->87. When that wasn't the cause I went back to the aftermarket ignition and 91/100 octane.