My bike is supposed to be derestricted, but doesnt go fast?

[simon1221]

This is not one of those 'easy answer posts' so anyway:


Rebuilt the engine last summer, new piston + rings + rebored barrel
Ran it in to the best of my knowledge but never got over 8000rpm (redline at 10500rpm)
Found the fuel level was too low so fixed it again
Turned the powervalve upside down because it wasnt running smooth (and now it does). This has the YPVS + servo + cables etc
Mixture settings all standard, new spark plug good spark and fuel.
When fuel was too low never went over 50mph
Now it doesnt go over 65mph, and thats only just

I adjusted the 'tang' before, but set it back to recently, so it should not be the fuel again.

Anything else it could be, I am going to try it on super unleaded soon and see if that makes any difference.

The power cuts out at 8000rpm rather than increasing...


____________________
DNA50 (sorry) ->> TZR125l >> GPZ500S

[sickpup]

Sounds like the PV isn't working.

[colin1]

run the engine in neutral, hold the power valve cable, and when you get the revs high, it should go stiff as it pulls the power valve open.

If it does this then your powervalve is stiff and needs cleaning, if not there is a problem with the servo that pulls the power valve maybe.

Having said this Im not an expert, but its a simple thing to try so worth doing.
____________________
colin1 is officially faster than god

[Kickstart]

[simon1221]

I have a feeling it is this, however before it coughed and spluttered all the way through the rev range, particularily at about 6k.

When I changed it it did run a lot smoother.
____________________
DNA50 (sorry) ->> TZR125l >> GPZ500S

[Finglonga]

Might be worth checking your throttle cable is adjusted correctly and all clips are in place too, then put the powervalve back as it was. Some sort of fueling issue.

Then get your mixture checked by a professional or you will blow the Fecker up.
____________________
Andy Sez....
F.Y.Y.F.F.

[distortion]

1) PV needs cleaning
2) Its restricted in the exhaust

Theres my worth

[simon1221]

1) PV is clean
2) No it isnt

but thanx anyway
____________________
DNA50 (sorry) ->> TZR125l >> GPZ500S

[Kickstart]

Hi

Some TZRs were meant to have had a restriction in the exhaust, but not all. Seems why some only managed about 85 when the power valve was turned.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing