4rt Wont Accelerate

[volcano island trial]

I recently got a brand new 2005 Montesa 4RT. It could be around 5 Months since it leave the factory and shipped to my country Indonesia. I Just started it (following all Manual procdure)and it run at idle perfectly. The problem is, it run very poorly when the accelerator is pulled . It feels like not enough fuel, (or too much fuel ? ). The manual says that it might be the TPS (throttle position sensor) is shorted out. As you know the TPS is part of the ECU.So I cant check any wiring. Anything else shall I check ?, Vaccum line clogged ?, Injector dirty ?. I have not opened anything yet.

Thanks

[ludde]

have you removed the restrictor between the ECU and the inlet? did you get it in a crater or did your dealer fix with it first

[sideup]

Luddle,

Not sure what you are refering to about restrictor between ECU and inlet.

I just changed to a programable ECU and swapped it out last week, no restrictor. Got mine straight from crate also.

Unless the U.S. Models with no lights, not street approved, does not have this restrictor.

Three restrictors in the U.S. import version 4rt: 1) between head pipe and head; 2)between header pipe and muffler; 3)one on the end of muffler (silencer)

Volcano: Have you checked the fuel? With that long of shipping time perhaps some water condensation in the aluminum tank? I have heard this happen on other brands.

[oz thumper]

All deliveries to Australasia (except the Repsol Replica) were fitted with a restrictor on the inlet side. Mine was straight from crate and restrictor had only approximately 10mm hole in it.

Also try changing the spark plug, mine failed after 20 mins running and caused backfiring and erratic running at higher revs.

[volcano island trial]

Thanks every body,

I never thought about restrictors . Why Montesa did that ?. Or at least they should have shown the procedure in the manuals. I think that could be the problem. The bike is brand new still in original crate, I bought it from a dealer in France, and I Guess, he did not prepare the bike to use since its going for another shipment anyway.

Will definetely try open the restrictor tonite !!, Looking forward to try this puppy this weekend. It is rainy season here, everything is slipery and slimmy. Let see if this thing better than my Sherco.

[volcano island trial]

Hi all,

I think I should share my experience to the Forum regarding the topic I started last month. Now my 4RT runs fine, I have great fun using it in the wet and slipeery section around here. Its really works !!.

The Montesa I got, I think its a standard Eroupean Version, comes with all regulatory accessories, various Lights, Turn signal Blinker, Horn even rear view mirrors!!. Apparently due probably for the same reason, the bike also come with various restictors. There are three restictors in the exhaust system alone, obviously noise control related. And there are two others, one is an air inlet restrictor and a ECU Software restictor. The last one is I found out to be quite dominant in the performance of the bike. To take out the ECU S/W restictor you have to disconnect a specific wire pin from the Accesory power connector. The instruction to do this can be obtained from the motorgas website (Thanks Martin!). Once this is disconnected, you can feel the difference ! Apparently the connection or disconnection of this pin change a specific ECU S/W program Map from one to another. Most people maybe dont know this since they took out the whole accessory Lighting Harness right from beginning , which in effect does disconnect the ECU map wire pin.

My only wish, I wish Montesa include this information or instruction in the already excellent owner manual.

[leetrial]

I have same problem.

I removed 4 restrictors one from air inlet and 3 from exhaust.

My 4RT was not generate enough power.

I just got very important new about electrical wire switch to change

the MAP of ECU.

I will try to disconnect this wire tomorrow.

Thanks very much.

[leetrial]

After remove one wire from connector, the engine was very good.

Lots of power.

I am really happy.

Thanks again.