CRM Mk3 Loses Power

[crm steve]

Can anyone tell me what might be causing my Mk3 to loose power when I change gearinto 4 -5 & 6 . The power valve is working fine, it starts easy it revs clear in 1st 2nd & 3rd but drops total power in the top gears. So far I have changed fly wheel stator, CDI unit, cleaned carb, fitted new DEP pipe, checked the wiring, new plug, had it strobed on the timing & even checked on a dyno (but no drop in power showed on this). I'm now lighter in the wallet department & my hair has gone grey, any ideas please.

[knackeredMk1]

Are you saying that you have dynoed it through the gears and it shows no loss of power .

What gearing are you on

[fishtail]

sounds similiar to NJhardy's problem?

viewtopic.php?f=6&t=8441

you guys should compare notes!

[crm steve]

[quote="crm steve"]Can anyone tell me what might be causing my Mk3 to loose power when I change gearinto 4 -5 & 6 . The power valve is working fine, it starts easy it revs clear in 1st 2nd & 3rd but drops total power in the top gears. So far I have changed fly wheel stator, CDI unit, cleaned carb, fitted new DEP pipe, checked the wiring, new plug, had it strobed on the timing & even checked on a dyno (but no drop in power showed on this). I'm now lighter in the wallet department & my hair has gone grey, any ideas please.[/quote]



The bike is on standard gearing & it's putting out about 35bhp at the back wheel according to the dyno. The bike is low mileage (8000 kilometers) & not been messed about with. Engine not been stripped or anything. Chap who runs the dyno thinks it might need a new piston, I'm not convinced as it's only in the high gears it happens & I'm talking major power loss ie: over taking a car would be a no no in these top gears. In 1st & 2nd it lifts the front wheel easy.

[knackeredMk1]

According to your explanation the only thing it could be is the interaction between the gear sensor and the ECU.

I know this is a bit drastic - Find a place where you can cut the wires coming from the gear sensor and be able to fit connectors to be able to reconnect them. Then cut the wires and see what response you get. The Mk3 ECU can run without a signal from the gear sensor as Eddie Evans of this forum runs his that way and you can always reconnect them if you find no difference anyway.

[njhardy]

Hiya Steve- seems we share a similar problem (pulling like a train up to 4th grear, then a seeming lack of power in 5 & 6 with no apparent reason). I fiddled with my gear selector sensor this weekend and also put my 150 main jet back in- in the hope that it may somehow change the problem. I couldn't see any problem with the sensor and it is in a sealed unit, so couldn't do much without getting inside the casing. Well, things seem to be much better. If it was the carb & jets, I'm not sure why it would help in higher gears and if it was a lose connection on the gear sensors, then that could mess up a lot in the ECU and powervalve. I suggest the gear selector sensor may be the problem- either damaged or faulty. My exhaust note still sounds much louder in 3rd than all the other gears, which makes me think that the PV is opening differently in this gear than the others...

[fallenmikethebike]

[quote="njhardy"]Hiya Steve- seems we share a similar problem (pulling like a train up to 4th grear, then a seeming lack of power in 5 & 6 with no apparent reason). I fiddled with my gear selector sensor this weekend and also put my 150 main jet back in- in the hope that it may somehow change the problem. I couldn't see any problem with the sensor and it is in a sealed unit, so couldn't do much without getting inside the casing. Well, things seem to be much better. If it was the carb & jets, I'm not sure why it would help in higher gears and if it was a lose connection on the gear sensors, then that could mess up a lot in the ECU and powervalve. I suggest the gear selector sensor may be the problem- either damaged or faulty. My exhaust note still sounds much louder in 3rd than all the other gears, which makes me think that the PV is opening differently in this gear than the others...[/quote


Hi, as an ex owner of an AR, this was something I noticed that it would do on occasions, resorting to the "flicking the ignition on and off trick would resolve it", but I took it as a portent of a PGM box about to mimic the parrot of the Monty Python sketch .
Mike

[njhardy]

Uh oh!! I hope she lasts out until I have to sell her in a few months time!!