I can potter around all day on it no bother,as soon as you grab a big piece of throtle it's like you hit the kill switch.

Bit reluctant to start but not too bad, five or six kicks from cold after i'd had the fuel pump out looking for crap, and three kicks when hot.

I've give it a basic service recently as I thought it was going down hill a bit. I've put the old air filter back in to check that the new one isn't restrictive,still no joy. No crap in the tank really, just a bit of slight dust.

The bike is an 05 and I got a spare throtle body with box of bits that came with the bike,so guess it's had a new one at some point. I'm quite new to the bike,only used it four time since buying it and ran great. I've been messing about with it recently getting it through MOT.

Any one got any ideas please?    

An easy thing to check is the radiator temperature sensor connector. If it gets disconnected, the ECU will go into limp mode and only run on low throttle. Not sure if the fan connector does the same, but might want to check it too.

Edited September 8, 20178 yr by sportsawyer
Clarification.

I have heard of this before, a hard re-set at an authorized Montesa/Honda dealer did the trick.

Valves could be getting tight if they haven't been checked for a while. Has the Bank angle sensor been linked out?

Edited September 8, 20178 yr by jrsunt

Thanks for the reply's guys.

I've had the wiring harness off when i connected the the lights and speedo for MOT so the plug socket thing is very possible, will have a look tomorrow,cheers.

  

Edited September 8, 20178 yr by cangy1000

Bank angle sensor,where's that located?

What would it look like...size,shape?

If it turns out it has been out, what do I have to do with it? May have put it back in upside down then,switch it back and should be ok?

The fan came on today as i was running the bike, so I guess thats connected and the radiator temp sensor controls that I guess so prob connected too. 

Edited September 8, 20178 yr by cangy1000

I thought the bank angle sensor was not introduced until the newer models....2014-ish??

Yeah, according to the 05 manual that I've downloaded...they have got one. It's a square box and it has to be 5mm away from the throttle body. I've been rumaging around that area, so hopefully I've put it back the wrong way up. Fingers crossed       

The B/A sensor sits behind the shock. There are 3 wires, white, green and I think red. Remove the sensor from the plug and join the green and white together. 

There is quite a detailed thread with pictures in the Montesa forum if you do a search

if you have lights fitted you need to remove white/green wire from head light loom plug to get the power mode as per hrc power pdi manual says can be found at montesa4rt .nl

 

Edited September 9, 20178 yr by on it
add info

went on one last week which packed up, then just ran on tickover blocked fuel filter.

Had a look at the pump in the tank, no sign of any crap really. Could try a flow test,think they give a flow rate/min.

Just had a look at the B/A sensor, I never touched that previously, but tried the bypass trick...made no difference  

Going to clean all the plug sockets with contact cleaner now.  

Change the spark plug recently?  If not might be worth a shot.

THREE BELLS   She's running like a good en.

As I was cleaning the plug sockets I came across a ball of wires with bits and bobs plugged in under the tank. It was the extension to the main loom for the road gear that I'd plugged in, and forgot about due to it taking an age to get though MOT. As soon as you plug the extension in it must run on some kind of limp mode.

Well done to "on it" who was...on it! 

Thanks for all the input. BRRRAP