PNW Moto

PNW Moto (
-   Mechanical and Technical (
-   -   '08 KTM 990 Adventure stalling on deceleration (

CodeBlue Feb 7th 2018 03:26 PM

'08 KTM 990 Adventure stalling on deceleration
Hi everyone, my bike is giving me some trouble and I'm hoping someone here has an answer. Last week I was coming up to a stop sign and when I pulled in the clutch the RPMs dipped well below 1,000 for a moment, then the bike died. I was able to start it back up without any problems, but on the rest of my ride home every time I slowed down it would die. Opening the throttle would give me short, jerky bursts (less than half a second of power), but ultimately it died as I turned into my driveway. I'm at a bit of a loss as to what the problem might be. It's had the well-known erratic idling problem in the past, but lately by rotating the throttle forward (closed) all the way manually the idle would return to normal. It had been idling a little rougher than normal the preceding week, but nothing outrageous.

Things that may be important: 45k miles, aftermarket full Remus exhaust, and the valves were adjusted about 7k miles ago.

Any help is greatly appreciated.

Scribbles Feb 7th 2018 04:56 PM

Hmm... sounds like a fuel problem to me..

Clogged fuel filter?
Bad fuel pump?

CodeBlue Feb 7th 2018 05:06 PM


Originally Posted by Scribbles (Post 43696)
Hmm... sounds like a fuel problem to me..

Clogged fuel filter?
Bad fuel pump?

That wouldn't surprise me at all. I had low fuel when it happened, so maybe a lack of fuel pressure to the throttle bodies? I just topped it off with a 5 gallon fuel tank I had and it's not giving me any issues now, so maybe increased pressure in the fuel line fixed it, which would indicate fuel filter or pump. One of the downsides to having a 2 mile commute and no fuel gauge is that you lose track of how much gas is in the tank. I guess I'll try swapping the fuel filter next.

I also just swapped out the clutch switch, since someone had recommended that to me the other day. In hindsight I should have tried those two things separately, but oh well.


Also, most of those google links are already purple. I just hoped someone here had dealt with it so I could pick their brain.

MarvTravis Feb 7th 2018 06:28 PM

I had a problem with my ZX-14 where the engine would repeatedly suddenly cut out and then resume with a violent surge. It was so abrupt, it was as though the ignition was intermittent. I pulled the in-tank fuel strainer integral to the fuel pump, and found it very clogged. As I didn't have a replacement strainer, I cleaned it with brake cleaner and a toothbrush, and reassembled the fuel pump. It resolved the problem.

In a second instance about 40K miles later, the engine exhibited the same problem as previously, (cutting out and then resuming). Removed the fuel pump, removed and replaced the fuel strainer integral to the fuel pump, and reinstalled the fuel pump. As before, it resolved the problem.

In a third instance, the engine began faltering slightly under load. The problem was found to be a loose connection at the battery negative terminal. Arcing at the loose connection had eroded the captive nut within the battery post to about 2/3 its original size. Replacing the captive nut within the battery post corrected the problem.

So... what may appear to be an ignition problem may be due to a nearly-clogged fuel strainer, or a poor connection at a battery terminal or ground connection. Reasonably-priced after-market fuel strainers are available on eBay.

PeteN95 Feb 8th 2018 08:26 AM

I had a similar problem with my Vstrom at about 50k. It turned out to be the throttle position sensor. FYI

NWSumoman Feb 20th 2018 02:11 PM

Sounds like water in the fuel to me.....

Sentinel Feb 20th 2018 06:27 PM

bad gas happens a lot. fuel strainer/filter is a bad gas symptom, too. bad gas.

MMcN49 Feb 20th 2018 06:39 PM

Also had a TPS issue on one of the Buell's. One of its three wires fatigued and broke at the sensor body. Some of the wire insulation remained in tack and with engine vibrations the copper conductor intermittently made contact with engine vibration. It took a bit to find.

Based on your posts I'm guessing you may have a fuel pump inlet strainer that's getting blocked.

All times are GMT -8. The time now is 06:15 PM.

Copyright © 2019 PNW Moto. All rights reserved.