velvetpants57 Posted November 24, 2015 Report Share Posted November 24, 2015 hello all, i have two 2005 Montesa 4rt's. one is a Repsol with under 20 hours and the other is a normal 4rt with a 260 kit and a ecu switch. the 260 is my work horse with a ton of hours but runs like a dream and has a domino fast throttle tube. i purchased both bikes from the original owner. the original owner had played with the throttle cable and taken the tps out of its operating perameter and the bike would not start. so i got it back where it needed to be and it now starts first kick. it unfortunately has an erratic idle that i cannot get rid of. it needed a new throttle cable so i replaced that and installed a new fast throttle tube. i set the tps take up in the throttle cable with the front wheel straight ahead. now when i bring the bike full lock to the left it idles way down and wants to die, when i go to full lock right it idles up to a fast idle. i have the cable routed just like on my 260 and have run out of troubleshooting ideas. i feel like i could fix the issue by slacking off the throttle cable like on a normal non fuel injected bike but with the Tps adjusted off of cable tension that is not an option. any input would be greatly appreciated thanks Dallas Quote Link to comment Share on other sites More sharing options...
copemech Posted November 24, 2015 Report Share Posted November 24, 2015 Never worked on a mont, but I can tell you that tps take up as you call it is not set with yhr cable. Ther would normally be a set screw on the throttle body that does that, or the tps itself is rotated for yhe proper base setting. Cable must have a bit of slack for turning as you noted. Quote Link to comment Share on other sites More sharing options...
jimmyl Posted November 24, 2015 Report Share Posted November 24, 2015 Hi Dallas The 4rt must have slack in the cable so the butterfly snaps shut. Tick over is done with the big screw on the side of the throttle body - just about accessible through the gap in mudguard /frame etc. I think this is an air screw so out for faster and in slower . Normal comments ref having a correct tick over to aid starting etc. If above correct then check no dirt in the in this air passage of the throttle body etc where the adjusting screw operates. Screw comes out ok with spring on end then WD 40/Air etc to ensure clean, would do with Throttle body off the bike to stop anything going into engine. Hope of some use Quote Link to comment Share on other sites More sharing options...
dadof2 Posted November 24, 2015 Report Share Posted November 24, 2015 Recently I came across an intermittent problem on a car (EFI). Mostly it would start first turn of the key and run fine. Sometimes however it had to be cranked quite a bit with a lot of throttle. Sometimes it juddered and stuttered for several seconds after starting. OBD showed no faults and voltages at all components that could be the cause were correct. Eventually it was found to be a plug in two pin connector inside the chassis (box section part of the monocoque). Water had got into the chassis and caused corrosion on one of the pins. This corrosion was acting as a resistor reducing the flow of current to the fuel pump (and hence low fuel pressure) when voltage was low during idling or starting. Replaced the connector - perfect starting and idling. Bearing in mind that the Honda ACG / capacitor system produces less than ideal electrical characteristics at low / idle RPM it may be worth checking the electrical connectors, specially those to the fuel pump. look for dirt, looseness, corrosion or fraying wires where they are crimped. Quote Link to comment Share on other sites More sharing options...
the addict Posted November 24, 2015 Report Share Posted November 24, 2015 hello all, i have two 2005 Montesa 4rt's. one is a Repsol with under 20 hours and the other is a normal 4rt with a 260 kit and a ecu switch. the 260 is my work horse with a ton of hours but runs like a dream and has a domino fast throttle tube. i purchased both bikes from the original owner. the original owner had played with the throttle cable and taken the tps out of its operating perameter and the bike would not start. so i got it back where it needed to be and it now starts first kick. it unfortunately has an erratic idle that i cannot get rid of. it needed a new throttle cable so i replaced that and installed a new fast throttle tube. i set the tps take up in the throttle cable with the front wheel straight ahead. now when i bring the bike full lock to the left it idles way down and wants to die, when i go to full lock right it idles up to a fast idle. i have the cable routed just like on my 260 and have run out of troubleshooting ideas. i feel like i could fix the issue by slacking off the throttle cable like on a normal non fuel injected bike but with the Tps adjusted off of cable tension that is not an option. any input would be greatly appreciated thanks Dallas Might be a sign of the fuel pump giving up. Quote Link to comment Share on other sites More sharing options...
cornishtwinspring Posted November 24, 2015 Report Share Posted November 24, 2015 Would the fuel pump dying give the different idles on different locks? Surely it would be constant from the pump. Quote Link to comment Share on other sites More sharing options...
the addict Posted November 24, 2015 Report Share Posted November 24, 2015 My 07 started to idle erratically, fine when riding though until it gave up a few weeks later. Quote Link to comment Share on other sites More sharing options...
jrsunt Posted November 24, 2015 Report Share Posted November 24, 2015 like jimmyl says, with plenty of slack in the cable set the idle correctly using the screw on the left side of the throttle body, then adjust the throttle cable slack. Quote Link to comment Share on other sites More sharing options...
baldilocks Posted November 26, 2015 Report Share Posted November 26, 2015 Addict have you forgot to post a fuel pump failure on a wash and ride 4rt ? Quote Link to comment Share on other sites More sharing options...
the addict Posted November 26, 2015 Report Share Posted November 26, 2015 Addict have you forgot to post a fuel pump failure on a wash and ride 4rt ? Quote Link to comment Share on other sites More sharing options...
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