overheating and trouble starting

LDiablo

LDiablo

Joined
Mar 21, 2021
Messages
19
Location
New Smyrna Beach FL
Bike
2010 NT700V
I have a 2010 nt700 and love it except for one thing if the wife and I are out riding in hot weather 8o degrees and up and we have been riding for a few hours and stop for gas or whatever, sometimes it doesn't want to start kinda like a vapor lock and if you allow it 15-20 to cool down it starts up fine any info will be appreciated jt
 
The sensor is the most likely problem. As for the overheating, how high does the needle go on the gauge?
As long as it does not go past 2/3 it is ok. At hat point the fan should be running.
I have replaced both the sensor and the thermostat previously.
I have actually found that my bike likes the hotter weather and runs better at 30+C ambient.

Macka
 
When mine went out, the check engine light came on and the bike blew a trouble code. We were in a Fred Meyer parking lot leaving for Spearfish. Frosty looked up the code on his phone. We knew what the problem was and having run into this before on cars, I knew that if you let the coil cool off a bit, it would internally reconnect enough for the computer to see the pulse for a couple of revs. Once the engine starts, the computer has "historical memory" and of course if it knows where the cam is and crank is and starts the engine, one or the other can open up again and the bike remembers the last position . Turn the bike off and it wont restart. Putting in another one isnt a bad job...just a lot of wrench spinning on the lower right front side of the engine. 1996 Subarus will do this and if you have a can of freeze mist, the cam position sensor is accessible and you can spray it and if that fixes the problem, replacement is easy.
 
Likely as others here said that crank position sensor. It fits the symptoms others have had.

Arknt
 
Before tearing into the engine, check the fault codes that are stored in the bike's computer.
 
The ECU will only set a DTC for this fault when the engine is continually cranked for an extended period without a response from the crank position sensor (from memory more than 15 seconds, which is a really long crank time).

Maybe @LDiablo can try this next time the problem happens.

Seagrass
 
When my crank position sensor went intermittantly awry, I had two incidents of hot no-start. One was at a gas station and the other was outside a convenience store. Both times I only used short cranks (less than 4 sec) to save the battery because I was more than two hundred miles from home!

Once home a few days later, I checked the codes and it showed a faulty CPS.
 
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Each time my NT displayed the sensor error, and failed to hot start, I charged the battery and this issue was not repeated.
 
Yes, crank sensors such as the 2-wire generator type found on the NT almost always act up just as described here, they become unpredictability intermittent before they outright fail, typically they get replaced before they get that far. This mirrors my experience with these things on customers cars.

What happens with them, the very fine gage magnet wire inside of them develops tiny cracks in spots after many heat cycles, then under just the right heat conditions a gap develops in the windings somewhere on the coil bobbin, leading to no output from the sensor. Cooling down the engine and the gap closes again and now the engine starts, only to fail again under the right conditions.

A lot of vehicle manufacturers have replaced these types of sensors with more rugged types using optical or other solid state means. It doesn't help on the NT that it's inside the engine in the oil, and on the NT the crankcase is not liquid cooled, only the cylinders and heads are. Some manufacturers like Ford put them on the outside of the engine where they can run cooler.
 
DirtFlier said:
When my crank position sensor went intermittantly awry, I had two incidents of hot no-start. One was at a gas station and the other was outside a convenience store. Both times I only used short cranks (less than 4 sec) to save the battery because I was more than two hundred miles from home!

Once home a few days later, I checked the codes and it showed a faulty CPS.
Click to expand...
Did you get a check engine light?
 
"....Did you get a check engine light?.."

I honestly can't remember because it was back around 2014-15.
 
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You can't always count on a code to appear, confirming it is indeed the crank sensor, even though that would be the ideal outcome. The ECM on the NT is not that sophisticated, and literally would have to catch it just right. It's more of a diagnosis based on symptoms.
 
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rc_heli_nut said:
You can't always count on a code to appear, confirming it is indeed the crank sensor, even though that would be the ideal outcome. The ECM on the NT is not that sophisticated, and literally would have to catch it just right. It's more of a diagnosis based on symptoms.
Click to expand...
Frosty refreshed my very poor memory on the NT incident I had. We had met at a Fred Meyer and when I started my bike to head to Spearfish, it started hard, but it started. Odd. I got a couple blocks away and then noticed the check engine light. We stopped and read the codes. After returning and putting in the new sensor, I then cleared the codes with the jumper.
 
Coyote Chris said:
Frosty refreshed my very poor memory on the NT incident I had. We had met at a Fred Meyer and when I started my bike to head to Spearfish, it started hard, but it started. Odd. I got a couple blocks away and then noticed the check engine light. We stopped and read the codes. After returning and putting in the new sensor, I then cleared the codes with the jumper.
Click to expand...

Not odd at all, these are typical characteristics of a failing crank sensor, totally unpredictable. Your vehicle may start, or it may not.

Chris, you obviously had your lucky rabbit's foot and four leaf clover with you that day. :rofl1:
 
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