Fuel Filter change (again)

[jonyboy247]

Hi blokes and gals,

Just wanted to ask a couple of questions in reference to changing the fuel filter(s) on my 50,000mile, 2008 650 strom.
The bike has started to lurch and stutter when going onto motorways, especially when cold and damp out.

I've narrowed it down to the fuel filters being blocked/clogged and was wondering how easy is to change them? am I right in thinking that there are 2? one inside the pump, and then another at the bottom on the outside?  
Can you just take them both out and give them a good clean and re install? or is changing them both the best option?
Don't really want to start drilling holes in things for the inline filter mod, and don't really want to spend too much money on getting the original parts sorted, and no way I'm paying my local dealers rates!
I've trawled through the forum and others and can't seem to find an exact answer I'm looking for.

cheers in advance

Jon

[Juvecu]

If you don't mind me asking, how did you narrow it down to the fuel filters without having a look at them to see if there's blockage? If it's just a case of having ruled "everything else out" then it might be worth doing a flow rate test first before you go through all the hassle of replacing fuel filters. There's instructions in the service manual for doing this. It's a simple test where you connect connect a hose to the tank and put it in a large container and then put 12V on the fuel pump so it runs. Measure it for a fixed time and measure the amount of fuel to calculate the flow rate. That way you can tell if your fuel filters are clogged up and causing low flow rate leading to starvation at high RPM.

Hopefully I'm not teaching granny to suck eggs

[jonyboy247]

, no worries, should have mentioned that I've done fuel flow test, checked SBV etc and can't seem to find a problem. the only thing I havnt done yet is check the fuel filters and seems the most likely cause. I havnt managed to get around to actually taking the tank off and having a look inside yet.

[Juvecu]

If there's no fuel flow issues, then the filters are unlikely to be blocked. Mine is on 106k miles, I checked the low pressure side's filter recently and it was very clean still, didn't even bother cleaning it. Obviously if you got some seriously contaminated fuel you might have a dirtier filter, but it doesn't appear to cause flow issues so it's unlikely that it's causing your problem. Still, it's easy to take the pump out and to check the filter, even to give it a quick clean if needed. I don't think you can get inside at the high pressure filter though?

The fact that the stutter is worse when it's cold and damn is probably a clue to what's really causing it, but I have no ideas at the moment

[Abercol]

Last time I had a bike that stuttered and misfired when going to join a motorway it was one of the coils failing - the damp got in, it shorted (but not noticeable at low rpm, just high) and the bike lurched and misfired, then it would pick up and take off, then stutter, stumble etc etc an intermittent fault that drove me mad until one day I could see the short as I revved the bike in a wet layby.

Replacing the coil sorted it in 5 minutes.

A temporary fix was to ride flat out for five or six (or more   ) miles as the heat produced dried out the coil.....and yes, a copper let me go with a stern talking to after pulling me over at 126mph for doing just that.  

[jonyboy247]

Cheers for the help blokes, I think you may be right Abercol, I think the front coils need changing.
when I get some cash together I'm going to replace the coil along with the filters in the fuel pump. may even go as far as doing the inline fuel mod! !