Jump to content

4Rt Only Runs With Fuel Pump Disconnected!


thall1
 Share

Recommended Posts

2 hours ago, thall1 said:

No it hasn't .... I'm getting 12v plus at the pump connector when it's being kicked over - it was lower than this with the old capacitor - and 14.2v when running. Rectifier has been bench tested- see earlier post... And it appears to be fine ... I guess proved by the Voltage output when running...

If you have swapped everything else, and ruled out the loom ....

Link to comment
Share on other sites

 

nothing left to swap out. Loom was stripped when I found the black wire corrosion on the capacitor side of the connector then once striped out it was found corroded back up almost to the crimp points into the loom. All loom wire was replaced and a new capacitor fitted..

Link to comment
Share on other sites

 
 

blockage in rubber hose from air box to Throttle body

Have you got the oil bypass tank going into air box still -are you blowing oil into air box confusing air mixture sensor.

If you have fresh oiled filter or even spray penetrating oil on the bike when it is running it effects the running starting of the bike.

 

Link to comment
Share on other sites

 

When you can not activate the fuel pump manually with a 12 volt battery externally connected, so the problem must be inside the fuel pump.

Try to measure the resistance at the fuel pump connector, when you can not activate the pump by 12 volts from an external source like a battery.

Another thing regarding the fuel pump connector is to verify that the power and ground wire is not wrongly connected inside the 2 pin connector !!!

As the fuel pump is operated as dc motor, it could turn the motor the other way around if the wires are misplaced inside the connector.

Link to comment
Share on other sites

 

Loom stripped and every connection was checked out  -only issue was the capacitor wire corrosion - no air leaks...checked with wd40 when bike was running as well as visual...throttle cable is fine...lot of slack to make sure at the moment. no relay under the tank on this one. its on the plate next to the rectifier...all checked out ok, just the earth block and lighting output connector under the tank...No oil in the bypass tank so nothing getting back into the airbox....the bike started yesterday with the airbox off (but only after 2 hrs of kicking /fault finding)...airbox/tank and wiring loom put back in while it was running...it was running fine without coughing or running rich....restarted ok when hot but got more difficult as it cooled down....tried it earlier this afternoon after being sat in a cold garage all night and it wont start...my guess(hopefully) is the temp sensor...

Link to comment
Share on other sites

 

the pump always powers up ok with 12v battery and when kicking there is 12.5v at the connector....but yesterday it didnt start even with 12v on the pump...as said previously I think it the temp sensor  - I checked the temp sensor plug wiring and no issues there.... 

Link to comment
Share on other sites

 

just tried the bike again....started ! but only once!!...took the temp sensor out and brought indoors...resistance check was 2500ohms as per manual....put it in boiling water and resistance dropped and came back up when left in air...put it back into the bike and it started first kick! and continued to start first kick thereafter!!! hopefully it is the temp sensor so a new one fitted when it arrives may sort it at last...wont hold my breath though!!!....think I shall be returning to a gasgas soon!!

Link to comment
Share on other sites

 

Have you checked the pick up on the generator? mine wouldn't start after id washed off & after much searching /testing of everything it turned out the pick up was loose either by vibration or just not done up tight. Retightened making sure was positioned correctly and off she went and has ever since. may be worth a check..

Link to comment
Share on other sites

 
 

A long shot but something else to consider...  There is a small chance that your throttle body could be getting an incorrect reading on the throttle position because its going passed closed.  I remember someone having an issue where they had a lot of the same issues starting your describing and they solved it by preventing the butterfly from closing all the way.   

I don't remember how they fixed it but I remember talk of a very thin washer, or small mound of supper glue and such talked about. 

Might be worth trying to tighten the throttle cable just a touch to remove all the play in the cable and give it a few attempts and then a smidge more if that doesn't work and try again.  Easy to do and undo depending on the results. 

Left field option but I figure at this point leave no stone unturned. 

 

Good luck. :icon_salut:

Edited by jonnyc21
Link to comment
Share on other sites

 
  • 2 weeks later...

hi all, just an update...fitted a new temp sensor....after 3 1/2 hours of checks and kicking it over I finally got it to start!...still running rough with black smoke...At this point I conceded defeat and gave the bike to Fred Adams at GLmotorcycletech@outlook.com.   The ECU was read with the diagnostic kit and it came up with Temp sensor and Injector fault. ...As a new sensor had just been fitted that seemed strange. After 2 days of swopping looms with his own bike plus other components then one by one swopping my bits back onto the bike with varying results it turned out to be an intermittent fault on the ECU.....A replacement ECU was fitted and its all fine!!!

Cheers Fred!

 

  • Like 3
Link to comment
Share on other sites

 
 

unfortunately because it was intermittent it threw us all off course! we had ruled out the ECU quite early on when it was fitted to another bike as that bike started and ran fine...

I am considering going back to a two stroke...the 4rt is great when its running but I have lost faith now....maybe a little unfair but this one just seems to be pup! I appreciate all bikes have issues but when these go wrong, trouble shooting is a pain! when a 2 stroke plays up there isn't much to look at, usually a leaky or blocked carb or a dodgy plug....

Fred has had four 4RT, apparently two have had ECU issues....

 

Link to comment
Share on other sites

 

Which 2t would you go back? I've been riding my 06 4RT since she I tore opened the box still a nice running bike with no serious issues, do need to change a fork seal now but what a great bike. I was thinking about a different bike to order but after talking with friends Im staying with what i know has been a great bike I ordered 2017 300RR I can hardly wait for it to come in. They tell me I should get April 26th. Seems like a long ways off 

 

  • Like 1
Link to comment
Share on other sites

 

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
  • Create New...