Bike won't rev over 4,000

[NorthernBoy]

As I get my damaged bike (attempted theft) in a condition to sell it's developed a new problem, and I'm hoping it's one that people have experienced with an easy fix.

On the way back from the dealers today to order a new ignition it stopped being able to rev over 4,000 rpm. It seemed to happen at bang-on 4k, and was as though it had hit a limiter there. Same revs in each gear and in neutral.

I parked it up, left it off for a couple of hours but have just started it up and checked again, and it's still revving to 4,000 but no higher.

Any thoughts?

 

[Arsey]

As I get my damaged bike (attempted theft) in a condition to sell it's developed a new problem, and I'm hoping it's one that people have experienced with an easy fix.

On the way back from the dealers today to order a new ignition it stopped being able to rev over 4,000 rpm. It seemed to happen at bang-on 4k, and was as though it had hit a limiter there. Same revs in each gear and in neutral.

I parked it up, left it off for a couple of hours but have just started it up and checked again, and it's still revving to 4,000 but no higher.

Any thoughts?

Hand guard snagging the clutch lever ? DAMHIK

 

[theoneandonly]

had this on a Griso ( guzzi ) .
melted cat/converter .
instead of 150 holes for the exhaust to go through , it had 15.

 

[DJ123]

Up until this level, does the engine sound healthy like it is firing ok?

 

[squibb34]

Assuming the engine doesn't rattle on start-up, I'm thinking a sensor is on it's way - cam position maybe. If so, I suspect it will show the CEL shortly if you continue riding.

 

[NorthernBoy]

Up until this level, does the engine sound healthy like it is firing ok?

Yes, it feels absolutely fine at lower revs. The fact that it cuts out completely at those revs and runs perfectly below suggests to me either that it's in a "limp home" mode after having detected a fault or that it's voltage / battery health / electronic in that it can only provide enough power to spark up to that level.

If it's the latter though I'd have expected it to come on at higher revs at first then as it ran down the battery to see the effect coming in lower down.

 

[DJ123]

My thinking is when does shiftcam cam come on? If it is a hard cut, such as the ECU is limiting it i would say it sounds like a sensor/electrical issue.

Have you had the error codes read?

 

[NorthernBoy]

My thinking is when does shiftcam cam come on? If it is a hard cut, such as the ECU is limiting it i would say it sounds like a sensor/electrical issue.

Have you had the error codes read?

I’ve not, it just happened on the way home today.

I could do without another issue at the moment, I’ve got to repair the ignition switch then get it advertised and sold by the end of the month.

 

[NorthernBoy]

It turns out there’s a crank position sensor fault, so this was likely the issue.

I’ve a new one arriving today and it looks as though it can be fitted without draining the oil, so I’ll give that a try.

Next step, hopefully is to sell it, and then spend the next year wondering if that was a mistake.

 

[NorthernBoy]

Well that was an easy fix. The new part took a couple of days to arrive, cost £50, and took about ten minutes to fit.

I leaned the bike well over to the right so when I removed the old sensor I only lost a few cc of oil, pushed the new one into the hole, screwed it in place and the bike's fixed.