Engine "Hunting" any ideas to the cause?

[JQL]

I have a problem with my 2010 Deauville NT700VAA. She has about 130,000 miles on the clock and about 200 miles ago the engine started "hunting" at certain revs and engine temperature. The revs are usually between 2,000 and 3,500 and the engine temperature at approximately the quarter mark.

Sometimes the Engine Check Light will come on but, only maybe 1 time in 4. On switching the ignition off and back on there are no flashes from the Engine Check Light.

If I rev the engine, the problem goes away. If the engine is hot i.e. in traffic the problem goes away. The engine runs normally at idle.

I initially thought it was a fuel problem but I've run the tank low then refilled with 95 E5 as normal and the problem is still there.

Any ideas?

 

[harryhendo]

Check the leads from the ignition coils to the spark plugs for any cracks or wear spots. You can use a multimeter to test their continuity. Also check the ignition coils themselves for any cracks, which could be tiny. You can also use a multimeter to test the coils themselves.

There is a way to check for problem codes stored in the ECU. I don't know what it is, but if the Check Engine light came on, there should be a code stored and that should give you a clue.

 

[JQL]

I'll start stripping the plastic tomorrow and see if I can see anything obvious. The problem is all motorcycle shops are closed in France for the next 3 weeks

 

[dnktng]

This might help to determine the cause of the check engine light (MIL)

 

[seagrass]

My 2007 NT700 was doing this recently and it turned out to be a loose connection where the spark plug lead connects to the spark plug boot.

Seagrass

 

[rc_heli_nut]

You may have a stored code, which would help you diagnose this. If you have the factory service manual, try retrieving codes by shorting the 2 wires at the test connector, as shown in the manual.

 

[JQL]

Well, it was the TPS. Initial voltage was 4.98 now it is 4.08. What a pain to calibrate it quite literally was either 3.99v or 4.08v nothing in between - though that could be my multi-meter.

What a pain to adjust with torx screws and no room to get a screwdriver in. Luckily I had a small torx key set which just fitted - first time I'd used it. Had it for a few years as I thought it might come in handy one day - just goes to show.

I have run the bike until the fan started and stopped a couple of times and no warning light. I'll take her out this afternoon for a test run.

Oh, and it looks like I might have got a slow puncture in the front tyre as the pressure is down slightly.

Good thing I retire at the end of this week so I've got lots of time to play.

 

[Phil Tarman]

Sounds like you've got things sorted out --- I hope it runs well this afternoon. Also, congratulations on your retirement! Up until this year, retirement has been great for me.

 

[JQL]

Sounds like you've got things sorted out --- I hope it runs well this afternoon. Also, congratulations on your retirement! Up until this year, retirement has been great for me.

Many thanks!

I still can't get my head around not working but getting paid

I hope your wife is on the mend and will be back with you as soon as possible.

 

[mikesim]

Congrats on the retirement John! Are you planning to stay in France or are you going to move back to old Blighty?

Mike

 

[DirtFlier]

JQL - because of the huge difference in internal volume, my front tire is often low when checked weekly while the rear either stays dead-on or within a tolerable +/- range.

 

[JQL]

Congrats on the retirement John! Are you planning to stay in France or are you going to move back to old Blighty?

Mike

Mike,

Many thanks. I'll probably stay on continental Europeas Blighty is too wet and cold!

 

[JQL]

JQL - because of the huge difference in internal volume, my front tire is often low when checked weekly while the rear either stays dead-on or within a tolerable +/- range.

On closer inspection, there looks to be a staple in the tread. As I'm at the office I won't try and remove it until I get home. Although I do have the equipment to repair the tyre, "in the wild" I'd rather do it at home. Hopefully, I won't get a sudden deflation. I've checked the pressure a couple of times and it's stayed static.

 

[WVRider]

Stupid staples. The brand new front tire I put on two weeks ago started slowly leaking. Couldn't see anything on outside so pulled and fixed. Was a piece of a staple. Sucked cause it was on my old Harley with a tube front tire . Glad you found the problem.

 

[DirtFlier]

On a trip to Vermont, I picked up a 4" framing nail in the NT's rear tire. The puncture was at an angle so required two sticky worms to seal. I let it sit for overnight with 50 psi then rechecked and it hadn't lost any air so I I lowered it to 42 psi and took a short day ride and rechecked it again and again. It was holding air without any measurable loss so I rode it home. Several days later, I did have to add air in western NY but I was still happy with my repair.

Once home I put the NT on my HF lift and ordered a new Michelin. It took 3-4 days for the new tire to arrive and by that time the tire had lost around 20 psi. Apparently getting the tire good and hot each day by riding helped the sealing but once it sat, the repair started to leak gradually.

 

[JQL]

I have a sticky (Gummy) worm in the rear tyre and it's holding. I must admit it got about 10 days of 2 hour rides in above 30°C heat immediately after, so that probably sealed it completely. Been in for 3 months now. I'm trying to hold out as they will be ready to change, both front and rear, in about 1,500 miles.

As it looks like a staple in the front, I'm going to try a DynaPlug which is smaller than the gummy worm. If that doesn't hold, then it's a Gummy Worm!