I am at my wits end trying to figure out what is wrong with my Riot. Here is the background as well as what I have checked thus far.

Around the first of November, I took the Riot out for two days worth of riding. Day one was perfect. No issues. Day 2, I started to notice, during steady, mid-throttle it would seem to bog and then recover quickly. Something like a bog in the 1 to 2 second range. I could tap the throttle a little and it would seem to recover. This was while running, constant speed (maybe 40 mph) with a mid to low throttle. Just crusing along.

I hadn't run it for about 2 months. And decided to take it out again at the end of December around the house (in the desert). It ran well in the beginning. But within about 20 minutes, I could tell it was getting worse. The bog under part throttle, steady was getting worse. It would clear when it was wide open throttle. Another 30 minutes go by and it is getting worse. Now wide open throttle is no good any more. And when jumping on it, it bogs really bad and I have to kind of feather the throttle to get it to come back. AFter about an hour of this is it so bad that I can't get it to go over 5000 rpm. So I can't get any speed or acceleration out of it. I limp it home doing about 20mph all the way home and barely make it home.

Diagnosis:
> Pulling it into the garage that day I could tell, while idling, it was running really rich.
> I removed the fuel pump and checked for sand, dirt, etc. No signs of crud. Put fuel pump back into the rig and started up. No difference. Running bad from the start.
> I replaced the fuel filter. No change.
> I checked the MAP sensor. It was dirty. I cleaned it with rubbing alcohol and a quetip. It went from black to that yellowish color. Reinstalled......no change.
> I got a new MAP sensor from a buddy here in town (thinking maybe the sensor was just bad, even though it ohm'd out per the service manual just fine). No change.
> I ohm'd out the fuel injectors. All good there (14ohms) on both. Book says 12ohms, but........as they are both the same, I figure they are good.
> I removed both plugs and inspected. They were wet......but not black. All looked ok with them and were gapped correctly.
> I ohm'd the coils, they were within service manual spec.
> Removed connector to computer and reinserted. No change.
> cleaned Air filter. It wasn't dirty........No change.
> I tried to check the cam sensor output. I couldn't seem to get the +5V variation when turning the engine over as the service manual says. But I figure that you can't get 5V out of it without the harness attached. Am I wrong?
> I have disconnected the MAP sensor's connector. It runs the same with and without it attached...........shity!
> I have reconnected the MAP sensor and disconnected the cam sensor. It runs the same with and without the cam sensor attached. Shity! And same as when I pulled it into the garage.

This is where I am at thus far. It's almost acting like it's in a "limp mode" whereby it is ignoring sensors and just going to a default setting. I say this because it seems to ignore any sensor I disconnect. But who knows.

I do not have a check engine light (the seperate one, not part of the tach) installed. I have one coming from RRR to see if it is lit (guess I could have done this with a volt meter on the wires, now that I think about it. I will check this tonight).

You guys got any thoughts? Wish I had someone local with the software and a computer to tap into the ECU and see what it is saying.

I had similar issues with my Riot. Turned out the crank position sensor wiring was melted and shorting out. Also may need to check fuel pressure.

That is one sensor/wiring (crank sensor) I haven't checked yet (don't know why I haven't). I'll look it over tonight.

Is there an easy way to check fuel pressure besides splicing into the feed line to the regulator? I'm not ready to jump to fuel pressure just yet as it is not running well at idle or part throttle or wot. But would like to know if there is an easy way to check it.

I've always spliced an inline fuel pressure gauge in the past, not sure of an easier way. To little or to much pressure will cause you some grief.

Look at the CPS pigtail connection by the valve cover. On mine it was exhaust leaking from the manifold to mid pipe joint that melted it down.

i cant remember but dont these revolts have a fuel return line on them..
if it does make sure the line is clear it can make it flood out

hey i read that post again and im thinking you should try checking that
gas cap and make sure its venting, ive seen that before were fuel would not flow after riding for a few miles

I have a seperate vent line on the tank. And it runs bad right from the beginning, right at start up before it can create a vaccuum. And just checked........removed cap, started it, still runs crappy.

Keep thinkin'.........I know I am.

I put a volt meter on the wires for the check engine light. It reads about 8.8V. So that tells me the engine light is lit.

I'm going to contact a local guy and/or Ride Now here in the valley to see if they have a PC with the appropriate software and harness to check the computer and see what it is saying. I would bet, within 15 minutes, it will tell me what is going on.

More to come...........

I've had similar problems from melted crank sensor wiring and especially voltage after I installed the ViPec ECU(iT hits 10.5 volts and limps). Also, keep an eye out for an intake manifold leak. Finding the ECU fault code checker will help. Keep us posted...

I would put a set of spark plugs in it first. I know you said they look ok but I've seen that before and they were still bad. We've had 4 cars have oil filled wiring connector from the stator. The one with the 3 yellow wires. Oil wicks up the wire insulation, goes into the black plastic plug and shorts out the wires. We've been draining the oil out of the connector periodicly and haven't had the bad running problem since. We've also had plugged fuel filters, but you changed yours. Did you check your battery cables. both ends. Also the main ground connection on the frame and the cables on the starter relay.

I replaced the plus before my last trip out. So they have all of about 2 hours on them.

I haven't checked for the oil filled wires.........I'll do that tonight. To be honest, it wouldn't surprise me if that is it. I noticed that the cam sensor had some oil in the connector. I cleaned it out, but didn't make a difference. I will definitely check the connector from the stator tonight.

Battery cables are tight at the battery and at the starter solenoid. I'll check the frame end of the ground tonight.