grim

Yes, that sounds right.

Works perfectly for 30 minutes, then it starts to explode in the exhaust system. Loses all the power and stops. The engine is warm after a few minutes, so heat is probably not the problem. The spark plug is full of soot / black. Since it works well without problems for 30 minutes, we think everything mechanical is fine (nozzle, gas pump, etc.). We have cleaned the connection to ECU, Checked all cables ++ Has anyone experience a similar problem?. Or have any idea what can result in a problem like this?

Throttle body is 2012 Honda standard, modified slightly by Future. Modification done: 28mm to 30mm opening.. Som function is normal as all Montesa, just a bit more flow. You have to remember that the Future Montesa is 99% same as any Montesa Repsol. Only difference is long stroke 80mm 292CC, cylinder head slightly modified valve out-take widen, and the throttle body as i said 30mm. So all functions are same as any Montesa Repsol/Cot a/RR or.. any 4RT. You can read about the modifications here: http://www.montesa4rt.nl/startpagina.php

Everytime i fix one problem.. a new appear. This time, fuel consumption is way to high. If we give full throttle, it kinda just lose power. Driving normal, we have flame from exhaust, also sounds like a Ferrari.. hehe. Explosions from exhaust. We checked the injector and sealings. All looking good. Tested the fuel pump and replacement fuel pump. Still same.. What else can do this? Grim

I found this on eBay.. its same pump, im pretty sure.. There is pump and filter almost free.. Checked up those pumps, so far i can only find positive feedback. http://www.ebay.com/itm/271381502452?_trksid=p2060353.m2749.l2648&ssPageName=STRK%3AMEBIDX%3AIT I'm not sure if it will do the job on the 4RT, but i'll buy it just to check. At that price, hehe. Same as a few beers.

Here is picture of the "teabag" filter. The second filter after pump i think there is quite a few we can use, simular ones. https://www.jottacloud.com/p/grimleiv/b1b5100beab2475fbf58f9a303d3b6d7 Think this is the second filter https://www.cmsnl.com/products/filter-comp-fuel_16900mbg013/

Think I will use fine Steel filter around pump. Should do the job. But annoying that they dont sell parts like that

Filter is standard montesa. But Honda only sell unit complete. HD have complete flat tank with pump £699. But i think i rather fix the one we have In fact most of the bike is standard. Differance is Engine shaft, piston, bored original cylinder to 292cc, modified original top and airflow to top. Some clutch modifications. Else its only titan bolts etc. So most is same as any 4RT So when i wanted to change piston and rings, that was not possible due Future modified. But via FB i found an option, 3 end gaskets, and i can use S3 280/310CC cylinder. So the problem now is that Honda don't deliver parts to fuel pump(filter, cable etc). They only deliver complete set as mention over.. So that is not good, due you have to spend around 500 pounds to get a part that would normally cost 20 or so

Any idea where to get a fuel filter. It looks like a teabag, never seen anything like this before..

Idle at 1800 when fan goes, 1900 normal. This bike has a flat tank, Future, with small pump etc. The filter, where can i get a replacement? Not possible to find it on any pictures, web sites, shops etc.

We tested the petrol pump flow as described in Service manual. Flow was ok. I don't know where the petrol filter is, but i guess inside the tank? But since the flow from return is ok, i assume the filter is ok also? We tested coil, condensator, cables etc. So strange it stall after 25 to 30min running time. Symptoms like its out of fuel..

Ok, the filter is inside tank, right? Else.. diagnostics, need to find someone around here that have the tools for that. You are thinking about heat fault in ECU?

2012 4RT

When I ride my bike(2012 4RT) during practice after it's hot and fully warmed up it starts to bog out or stall like it's missing petrol. But it only happens at a specific moment when I give it a bit of throttle and get some RPMs, pop a wheelie or ride up a steep hill etc. I was wondering if anyone knew or had an idea of what it might be Thanks

Solved the problem wiht decompressor It was bent, but nothing to do with it. So just run with it as it is. So i edited post. Forgot change heading hehe.