Author Topic: Possible fuel/injector issue (Read 31227 times)

Fat Rat · « **on:** February 15, 2016, 16:58:07 »

The K7 DL650 I bought recently had been standing for a year completely unused. I drained the fuel from bike but there would have been some left in the pump/pipes/injectors.

I have ridden the bike and it has performed just as I'd expect, however, there now appears to be a fault which sounds to me like it's fuel related.

On a long ride the bike gets progressively worse, first peaking at 6000 RPM, then 5000 RPM and then all the way down until only 30MPH is possible. Park the bike up for a short time and it improves.

Does this sound like congealed fuel somewhere/ If so, any recommendations on an additive that may clear it or is it a strip and clean job?

endintears · « **Reply #1 on:** February 15, 2016, 18:04:33 »

Hi
If it feels like fuel what about a blocked tank breather, but could be engine temperature related electrical/engine management fault.

grumps · « **Reply #2 on:** February 15, 2016, 18:22:11 »

Leave the filler cap undone and see. My guess same as endintears'

tallpaul · « **Reply #3 on:** February 15, 2016, 18:59:08 »

Trapped breather tube was my guess. l seem to have been out thunk again...

joderest · « **Reply #4 on:** February 15, 2016, 19:02:14 »

does the fuel system have a filter that could be blocked, sounds like fuel is struggling to get through somewhere.

Hondaman · « **Reply #5 on:** February 15, 2016, 19:34:46 »

Can you explain what happens ie what gets progressively worse?

Fat Rat · « **Reply #6 on:** February 15, 2016, 19:46:07 »

Loss of power, available revs decreasing from 6k down and down until the bike is only capable of 30mph.

Due to the history (bike standing), I suspect stale fuel or a blockage resulting in fuel starvation. The fact that the situation improves after a short pause also points to starvation?

Hondaman · « **Reply #7 on:** February 15, 2016, 20:04:46 »

Does it have a surge/stutter/misfire?

Reason I mention is I've refurb'd a couple of bikes that have stood, 1 had the above (a stutter/misfire/loss of power only when warm, in the midrange & only under load) that progressively got worse as the bike warmed up.
After lots of disassembly, checking, reassemmbly, heads cratching etc I was convinced it was fuel starvation - it turned out to be internal corrosion in the plug caps so might be worth checking primary & secondary resistance through the coils/ht leads & plug caps, probably various other leccy connections (battery & RR)
A long shot maybe but easy enough to check, however from your description maybe not the case.... perhaps check the tank vent.

Good luck, they are often daft niggly things but can be infuriatingly hard to find but strangely satisfying when you do track it down!

Phil

Gassoon · « **Reply #8 on:** February 15, 2016, 20:17:15 »

Does the engine get hotter than you would expect on your long ride? Judging from your long experience with vstroms ;-) What do the plugs look like? Too light, brown and burned looking?

Open the filler cap and run your finger round the inside of the tank...that's right, slowly, you bad boy! Is there rust on Your finger? If the bike was stood outside without fuel for an age, it might have rusted?

Try some good old fashioned redex in the fuel? Or that yankee stuff (I think) called 'Seafoam' ?

greywolf · « **Reply #9 on:** February 15, 2016, 21:31:18 »

I'd go with a clogged high pressure fuel filter.

See the test at http://www.vstrom.info/Smf/index.php/topic,3981.0.html

If you get a low result, for a cheaper remedy than buying an expensive new one, see http://www.vstrom.info/Smf/index.php/topic,6105.0.html

bosnjo · « **Reply #10 on:** February 15, 2016, 22:07:55 »

There is one very easy test you can perform:
Ride the bike until it lose the power. Stop it but don't shut the engine off. Use your spare key to unlock petrol tank cap and put you ear close to it. Open it and listen if you hear strong suction noise. If you do, you just did the reset on the vacum formed inside the tank. Close the cap and ride the bike straight on. See if all the power was back to normal. If it was, then you have clodged breather pipe somewhere. Do you have chain oiler that uses the vacum to oil the chain? If there was the vacum problem the oiler may be the one to blame.
Don't know, this is just one of possibilities, easy to test out.

Fat Rat · « **Reply #11 on:** February 16, 2016, 05:23:40 »

Thanks all,

I should explain the reason for some of the questions, I have sold the bike and it's the new owner that is experiencing the problem

V-Strom3 · « **Reply #12 on:** February 16, 2016, 18:41:59 »

Has the new owner joined on here?

Gassoon · « **Reply #13 on:** February 16, 2016, 19:08:45 »

Let us know, Andy, it should be a fairly easy fix, given the symptoms. I can understand how it slipped past you, not having a chance to get it on an extended run

Fat Rat · « **Reply #14 on:** February 16, 2016, 21:44:52 »

Actually Dave, the day before he collected it I took it on a 50 mile road test, it ran like a dream

tallpaul · « **Reply #15 on:** February 16, 2016, 22:18:03 »

He's filled it with diesel...

UK_Vstrom650 · « **Reply #16 on:** February 16, 2016, 22:27:26 »

Does seem odd if it worked fine for you

Maybe he's installed something and disturbed something else under the tank?

pr · « **Reply #17 on:** February 17, 2016, 09:45:17 »

Hi all
This is the new owner

Thanks for all your input.
So I haven't had time to do much testing. But as Fat Rat described, there is a loss of power after a few minutes of riding. Rpm doesn't go over 6k, then slowly the max goes to around 3k. It's not limited at those rpm's, but it seems to drop to idle then. Starting and idling is always fine. Switching off engine for a couple of minutes seems to reset a bit. No warning lights or error codes.
I've added Wurth petrol additive, recommended by Streetbike in Birmingham. Still need to burn the whole tank through: I didn't have more time than a 30 mile run, and motorways are not really an option with 40mph, so need more time for that.
Will definitely try the fuel cap test.
The engine doesn't get too hot (AFAIK temperature on the dash was always in the middle range).
I didn't change anything under the tank. Also no Diesel ;) Last top up was with BP premium stuff.
The first ride was just under 200 miles, and most symptoms weren't really present in the first 30 -50 miles (I took A-roads all the way). That could help explain why that first 50 mile test ride went fine.
I could try and add some Redex as well. Is it OK to mix with the Wurth stuff?

I will write how any further tests went!

Paul

bosnjo · « **Reply #18 on:** February 17, 2016, 10:15:51 »

To me, it sounds like negative pressure in the tank, again. If you say 50-60 miles after, and the problem shows up, it sounds like some fuel was consumed and air can't enter the tank.
The fuel cap test you can do even without stopping. Just keep spare key in the lock of the cap and when problem shows up, simply open the cap while riding. If the negative pressure in the tank was the problem, it should get better in 4-5 seconds.

pr · « **Reply #19 on:** February 17, 2016, 10:40:39 »

Thanks

I read something about vented and non-vented caps here: http://www.stromtrooper.com/maintenance-how/63893-gas-caps-vented-non-vented-how-change-tumblers.html

Do you know how to determine the vent is in the cap without taking it apart?