NC700X Hard to Start Intermittently

[Jerrdawg]

I drained the tank. Installed fresh gas with some FI cleaner last week. Still had a hard time starting but seemed to be getting better. This morning it totally didn't want to start at all. I finally got it moving and after the 2 mile drive to work it started up just fine. When I came out of work today I thought I would take the longer loop home. Well after a mile my Temperature light came on. I immediately came home. About 5 hours later the Temperature light is off, but the fan starts up immediately. I swear this bike is going to be the death of me. I have no idea where to start with this one. May be time to call in the dealer?

 

[HarveyM]

I would start a new thread for this, but the first thing to check is the coolant level. Don't take the radiator cap off (it's safety screwed on), check the overflow tank which is behind the lower 'chin' guard (where the oil filter is).

 

[670cc]

Yes, checking the coolant level is the place to start. It would also be wise to check the coolant temperature sensor and inspect the radiator for blockage, although I can’t imagine how it could be blocked unless it was packed with dried mud.

 

[b_rubenstein]

If the coolant tank is empty, with a cold engine, I would take the cap off the radiator and see if there is coolant in the radiator. If there isn't any visible, I would fill the radiator and the coolant tank. Walmart sells Asian formula Valvoline/ZEREX (blue color) that is appropriate for Honda vehicles. Also, check the oil level. The engine holds a little over 3.5 qts of oil, which is quite a bit for that displacement and state of tune of the engine, and should be able to cool the engine when idling run for several minutes without the engine over heating.

 

[670cc]

I haven’t re-read your whole story, but a thought came to mind. If the coolant temperature sensor was faulty and the ECU erroneously thought the engine was warm when you are trying to do a cold start, the fuel mixture might be wrong and cause difficulty in starting.

 

[Jerrdawg]

I haven’t re-read your whole story, but a thought came to mind. If the coolant temperature sensor was faulty and the ECU erroneously thought the engine was warm when you are trying to do a cold start, the fuel mixture might be wrong and cause difficulty in starting.

Thanks 670cc for pointing me in the direction of the temperature sensor (ECT Sensor). Just paging though the shop manual some of the symptoms are Hard start at low temperatures and cooling fan turns on. I did not run it at all today. As soon as I turned the key on the fan kicked in and the temperature light was on. but it started way easier. I'm guessing (well hoping) the opposite will happen in the morning. Does not look like it would be that hard to replace.

 

[670cc]

Thanks 670cc for pointing me in the direction of the temperature sensor (ECT Sensor). Just paging though the shop manual some of the symptoms are Hard start at low temperatures and cooling fan turns on. I did not run it at all today. As soon as I turned the key on the fan kicked in and the temperature light was on. but it started way easier. I'm guessing (well hoping) the opposite will happen in the morning. Does not look like it would be that hard to replace.

If the fan turns on immediately upon turning the key, well there you go; should be an easy fix. It could even be a connection problem at the ECT, but hopefully the manual has a test procedure to prove the ECT itself is faulty.

 

[Jerrdawg]

Thanks to everyone for the suggestions. My issues was related to the the Temperature Coolant Sensor. As soon as I replaced the sensor the issue disappeared. Hard to believe it failed so early in the bikes life, but I know it happens. Thanks again!!!!