Bike intermittently losing power around 5.5k RPM

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Bike intermittently losing power around 5.5k RPM

Postby RyanD » Thu Jul 19, 2018 6:24 pm

Posted this over at, but thought I'd check here as well.

Call me Ishmael. Some years ago--...

This past weekend I went on a 3 day organized moto-camping rally through Oregon. I did about 1,100 miles over 3 days. My bike started intermittently losing power, sometimes dying, while cruising along at a decent clip and trying to roll power on. It always happened when I had been going at a steady pace for a while.

About 5-6 hours in to day 1, after several hours in temps >100 F I experienced the first malfunction on this bike. I was on the interstate, going about 85-90mph in 5th gear at about 5000 RPM (and had been for at least 10 or 15 minutes), when I decided to do a roll on and pass a car going up Cabbage Hill just outside Pendelton, Oregon. Cabbage Hill is an interstate mountain pass that leaves Pendelton OR (elevation 1200 feet) and has multiple switchbacks, gains about 2000 feet in 6 miles, and eventually summiting at 4,100 feet. This is a cool video of an FZ09 taking that route.

About halfway through all the hairpins I opened the throttle expecting the bike to take off like always, but rather than shoot past the car, the bike lost power. Even at wide open throttle the RPMs wouldn't go above 5.5k RPM, the engine started lugging, and the bike slowed significantly as if I were engine braking. Twisting the throttle just made the bike slow down and me lunge forward in the seat. I downshifted to 4th, same story, and then 3rd, same story. I could pull in the clutch and rev the bike to the limiter without problem, but under load the engine wouldn't go above 5.5k RPM, and wouldn't maintain speed. I safely exited the interstate, shut the bike off, and pointed it back towards civilization (15 miles back the opposite way). It was 105 degrees F. The bike ran perfectly all the way back down the pass, 15 miles to the nearest gas station.

I pondered what to do, checked the oil level, checked the battery voltage displayed on the dash (14.1 when running), checked the chain, clutch felt fine, checked coolant level in the overflow which was fine, filled up the gas tank (was previously at about 3/4) and decided to try again.

I went back up the hill, made it about 2 miles further than last time and the same thing happened. Except this time the bike stalled. I pulled over on the side of the interstate, and got the bike restarted again. It started with no problem. The next exit was 6 miles away, and the bike died once more on the way to get off the interstate. Once I made the exit and turned around it ran perfectly back down the mountain, about 20 miles back to Pendelton, OR.

I decided I was gonna need to get a hotel, so I rode all around Pendelton looking at my options. I flogged the bike the whole time in town, and it performed perfectly. Then I saw a group of people on the same rally as me get on the interstate heading up the hill for camp (2 more hours away) and I decided that I was going to try one more time. I went back up the hill, and it died 3 or 4 times before I got to the summit of the pass at 4100 feet. I restarted it every time without a problem. Sometimes I'd make it only a couple minutes before it happened again, sometimes a little further. Once I passed the summit at 4193 feet, I continued on uneventfully for another 2 hours to Joseph, OR (elevation 4190) .

The next day I rode from Joseph OR to John Day OR, about 200 miles. The bike performed flawlessly up until I was about 5 miles from camp. Just outside of camp the bike did the same thing as before. I was cruising at around 70mph in 4th, and rolled on and all of a sudden lost power. I couldn't rev over 5-ish thousand RPM, engine was lugging almost as if engine braking, wouldn't maintain speed, and this time shut off. This was on a flat road, no incline or corners. I restarted the bike without problem and carried on to camp in John Day, OR (elevation 3,087).The temperature was 99-100F in John Day, whereas it had been in the high- mid 80's during the first parts of the trip.

On Day 3 I rode the bike from John Day, OR to Mulino, OR, about 325 miles. I was about 120 miles into the trip when the bike lost power again. This time I was just outside of Prineville, OR, and had just come over the Ochoco summit (4,731 feet) a few miles back. The bike had descended for a couple miles when it happened, and temp was around 93F. All of a sudden, cruising along around 80 I tried to roll on for more power, and the bike just wouldn't rev past 5.5k RPM. This time however the bike did not die. I couldn't rev past 5.5k in 4th. I pulled the clutch in, hit the rev limiter and shifted to 3rd. I still couldn't get past 5.5k in gear. I once again downshifted into 2nd and hit the rev limiter with the clutch pulled in. When I let the clutch back out I was finally able to pass 5.5kRPM while in gear and I carried on getting back up to 85MPH in 4th and 5th gear. The entire time that I couldn't put load on the engine the bike was slowing significantly. Turning the throttle in gear just made the engine lug and the bike slow further. I carried on the rest of the way to Portland in 93-99 degree weather without incident.

I got home Monday morning and went to sleep. I went back to work Tuesday and have commuted both Tuesday and Wednesday on the bike without issue. My commute is about 10 miles each way, without any crazy elevation changes.

Maybe some important background:
Bike is a 2014 1290R. 18,300 miles at time of first power loss (now has 19,300).

Mods include: De-cat, remus link pipe, remus hyper-cone, tail tidy, integrated tail light (10,000 miles plus), galfer rotors (4000 miles), Rottweiler intake, Rottweiler emissions delete, PCV with map from Rottweiler (1200 miles at time of incident), Oberon clutch slave (300 miles at time of incident).

Bike was serviced 1 day prior to the rally at local dealer, but they did not have time to perform the valve check. I opted to do the 18,600 mile service early so it would be tip top for the rally. Unfortunately they only got around to changing the oil, cleaning the air filter, and other routine stuff that I could do myself. They didn't get to the valve check, fuel pump/pressure check.

Dealer oiled Rotty filter with Maxima Fab1

Weather was HOT. Many hours on each day were spent in sustained temps > 100 degrees F.

At the time of the first incident the temp was 105 degrees, and the bike had been running for 6 hours in similar temps. I had just taken an hour break immediately before the first incident, but left the bike on un-covered blacktop while I had lunch.

Oil temp highest reading was 220F but my feet felt like they were on fire when on the pegs.

The bike had run a mountain pass the day before without incident, although that was only a 2 hour ride to a 5,000 foot pass in temps around 90 degrees at the summit. (Government Camp, OR).

I recently added a Rotty intake, emissions delete, and PCV with map from Rottweiler. I had already ridden over 1000 miles on this setup without problem.

Oberon clutch slave was installed the day before the trip by me. It felt great, operated just fine as far as I could tell.

Possible culprits?

It seems like heat and elevation are related to this issue, which makes me think I may have a bad air/fuel mixture that is exacerbated by atmospheric oxygen pressure changes.

It also seems like losing power under load, especially going up a hill in hot weather is a common finding when a fuel pump is failing. However, the fact that I could rev it to the limiter when I pulled the clutch in makes me think fuel delivery must be ok?

I do not yet know the condition of the fuel filter. I was using 92 octane gas. Oregon gas is notoriously bad quality and known to occasionally have debris in it. I probably had a mix of 10% ethanol and non-ethanol premium gas in the tank at the time.

I do not yet know the condition of the spark plugs. I just haven’t had time to take off the tank and look around yet.

The battery was showing 14.1 that day. Today it was showing me 13.8V while sitting in stop and go traffic, and would climb to 14.1 - 14.2 when riding fast. It is the original battery that came with the bike. It sits on a tender when I’m not riding much. I haven’t placed it on a battery tender since March, because I ride almost every day.

When I installed the PCV plugs into the stock crankshaft position sensor I couldn’t find a good place to put them, so I ziptied them to the frame on the left hand side of the bike. The wires sit kind of close to the front cylinder and I wonder if they could have gotten too hot? They are not touching the front cylinder.

I don’t know if vapor lock is possible on a fuel injected engine? I never checked for a whoosh in the gas cap or anything.

At this point I’m going to bring it back to the dealer on Tuesday for the scheduled valve check. He’s also going to run a fuel pressure test and check out the fuel pump. Is there anything else I should check or have him check while it’s in? I don’t think they will be able to reproduce the problem, since it happened so seemingly randomly and infrequently in a 1000+ mile trip. However, I really want to find a definite cause for this, because having an engine that loses power at random intervals does not inspire confidence for remote solo touring, nor aggressive cornering.

I appreciate any help I can get!

The end.

Minimoto racer
Posts: 36
Joined: Mon Mar 09, 2015 3:05 am
Location: Japan

Re: Bike intermittently losing power around 5.5k RPM

Postby cubfoot » Mon Jul 30, 2018 7:58 am

Chiming in although I'm by no means as knowledgeable as most of the peeps around here.

Hot temps, altitude, freshly oiled filter and rotti map could indicate that she's running to rich especially if she's bogging once you open the throttle...? A look at a spark plug might show you something (definitely if it would be a 2-stroke, :D sorry).. any misfires?
Otherwise, your opposite suspicion, that she's running too lean --> faulty fuel pump could be quite true as well. Revving to the limiter without load is no indication of a perfectly functioning fuel pump btw, could be that the heat is messing with the pump? Again, a quick look at the spark plug might reveal...
Just my 2¥
Good luck!
Nice route btw!
don't buy a 701 when you want a 1290

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