Maybe when the idle screw is turned in to much, so the bypass is closed off to much, to get enough air through for the injection sensors to work .

Edited August 23, 201511 yr by guys

I have also been told that if the idle screw is too far away from 1800rpm, the ECU will s**t itself and will disable starting by not allowing a spark.

Alan Bird at FEETUP Trialsport is very knowledgeable too and has helped me out no end over the years with various bikes. I think he has and still works on every trials bike available.

I have a no spark situation with my 09, (didn't think we needed a new thread?)  first off I found the pulse coil to be bad (open circuit) and replaced the stator only to find that I still had no spark.  All resistances are within spec as per the manual except for the coolant temp sensor was 4.5 ohms rather than 2.3-2.6 ohms at 20 degrees C, the temp I had while testing was closer to 5 degrees C.  I have tried jumping the two outside terminals on the bank sensor as suggested here also.

Does anyone know the correct sequence to test the rectifier?   All the connections seem good and clean, not sure where else to look.....

Have you checked all your grounding (earth) connections including the yellow connector block under the fuel tank to be sure verything is correctly connected to ground?  I ask because the ground connector block looks like its just a capped connector but really has a pice to connect all of the spades together. 

 

I am guessing this is a yes, just double checking...

Edited November 3, 20169 yr by jonnyc21

I did check the ground connections and the yellow connector block, all sound though I was surprised how dirty the yellow block was when I took it apart.  

There are a few good YouTube video's on testing a motorcycle rectifier.  you might give a search for "test a motorcycle rectifier" in google and watch some of the videos. 

 

The last time I had issues with a bike not getting spark, a Suzuki GS500E, I ended up replacing the rectifier and it didn't fix anything, turned out it was the pickups on the flywheel not telling the system when to spark... 

 

I wish I had a known process for the 4RT, Good luck. 

So I have the spark problem solved, turned out that it was just the pulse coil.  I borrowed a friend's 4rt to swap parts to trouble shoot and first thing I tried my spark tester on his bike just to get an idea what I should be seeing and it had no spark on the tester either...hmmm....soooo if I use the spark plug as a test unit both bikes have spark!  After that revelation I reassembled my bike to try and start it but after many kicks and re-setting the edu kicks it would only sputter a couple of times and not start.  I pulled the fuel tank and injector off the other bike and with these in place my bike fired up after three kicks.  With my tank and injector back in place after many more kicks it did finally start.  In the manual it states that there is a filter and it looks like it is in the tank, anyone have experieince changing it and are they available?  I don't have the setup to try and test the fuel pressure at the injector as detailed in the manual..  I will try the pump volume test as in the manual tomorrow, any other ideas?  This bike has been a bit tough to start since I bought it actually, especially at high elevations.

You can clean the "tea bag" fuel filter in the tank with carburetor cleaner (or brake cleaner) and compressed air.

Haven't come across a replacement filter yet.

I looked at my filter for similar reasons, ymir, but it was clean. It is a very coarse filter, quite unlike a normal inline petrol filter, and I don't see how it would catch the usual fine stuff that can occur in petrol.

Remove the tank bottom and take the pump off. The filter lies beneath the rubber bit.

the "tea bag" filter is only there to protect the fuel pump, the really fine filter is in the small round metal container that sits on top of the fuel pump.

So I pulled the pump out today and found that the filter was basically plugged, the and#39;tea bag' filter on the pump was filthy and the sump that the pump sits in was rusty!!!  Pulled the pump out before I bothered to try and volume test it.  

 

Tomorrow I will call my dealer and see about sourcing a new filter and figure out the best product to coat the fuel sump so the rust will not continue to be an issue.  Caswells is the only one that I know of, any other ideas?

Has anyone seen a rust issue like this?  I noticed on the new models they have changed this to plastic.....?

I'm sure you could test some scrap domestic plastic for petrol resistance then just put a bit in the depression, held in place by the teabag, to prevent rust being drawn in to the pump.

I'm sure you could test some scrap domestic plastic for petrol resistance then just put a bit in the depression, held in place by the teabag, to prevent rust being drawn in to the pump.

http://www.aspenfuel.co.uk/

Is it possible that the corrosion may be the result of bad fuel?  I know for a fact that the PO used regular fuel in the bike, most of which would be ethanol blended here now.  I always use ethanol free premium.  I'm worried that if I don't seal up the sump that it will continue to corrode even if I put a poly liner of some sort under the pump intake.