Nc 750. 2019. Won’t go

[JJH]

Nephew David was riding along and bike lost power. Went to someone I don’t know but he couldn’t fix it. Got it to my brothers house. Looked at it yesterday. Has spark has compression. Has fuel and easy start. It just won’t fire. Tried everything I can think of. Used jump leads because it said on the web that an iffy battery that apparently was ok would cause those symptoms. Plug leads are on right way. They don’t suffer from dicky ecus. Anyone any pointers? Any previous experience? HELP. JJH

 

[Pip5ter]

Injector maybe?


Sent from my iPhone using Tapatalk

 

[richh]

Deffo one of those big 3 I would say.

Spark, have you pulled both plugs and verified?

Fuel, how do you know it's getting to the combustion chamber? (Though you would think easy start would fire it regardless.)

 

[sye]

Cam chain snapped?

 

[JJH]

Injector maybe?


Sent from my iPhone using Tapatalk

But it should run on easy start. JJH

 

[JJH]

Cam chain snapped?

It has compression. JJH.

 

[JJH]

It has compression. JJH.

Could the cam timing have jumped? JJH

 

[sye]

If it has a spark and compression, then it must be missing fuel. It's also unlikely that both injectors would be blocked, but you never know.

Edit: I've just seen that it won't start with easy start, that's me stumped, sorry.

 

[glenn2926]

Err, a daft question but he hasn’t put diesel in it has he?

 

[JJH]

Err, a daft question but he hasn’t put diesel in it has he?

No. That was eliminated in the early stages. My own experience is that even with diesel the engine will run on easy start. Don’t ask how I know. 27 litres of diesel into a 850 gsa. The stated volume is 24 litres. JJH

 

[Santa-2512]

You havnt said

does it have spark

Thats the only thing you havn't eliminated / confirmed

 

[JJH]

You havnt said

does it have spark

Thats the only thing you havn't eliminated / confirmed

Has spark. Has compression. I did say. Is getting easy start. Is there a good enough spark? I don’t know. I’m hoping someone has prior experience and can point me in the right direction. JJH

 

[Cortina]

Well , there are only 3 (Three ) things it can be. Fuel , Electrical , or Mechanical.
One of them (or 2 or 3) is NOT working ... first job , find out which of the three it is ... and go from there.

PS , Don't tell me all 3 are fine .. if they were , it would run !

 

[JJH]

The only thing I can think of is is the spark at the right time? Or is it strong enough under compression? Or has the valve timing somehow jumped a tooth? But there’s no backfiring. I haven’t got the equipment to check all the electronics and probably haven’t got the knowledge to do it. I cut my teeth on points and distributors. I was hoping in desperation that someone would have a eureka moment and point me in the right direction. I’ve bypassed clutch side stand switches. I should be on the Honda forum. Was chaceing a lead there where a nc750 was running out of puff and wouldn’t pull anywhere. Turned out that the clutch was slipping. Why he didn’t say that the engine was revving grand I don’t know. This problem started by the bike loosing power. JJH

 

[Cortina]

The only thing I can think of is is the spark at the right time? Or is it strong enough under compression? Or has the valve timing somehow jumped a tooth? But there’s no backfiring. I haven’t got the equipment to check all the electronics and probably haven’t got the knowledge to do it. I cut my teeth on points and distributors. I was hoping in desperation that someone would have a eureka moment and point me in the right direction. I’ve bypassed clutch side stand switches. I should be on the Honda forum. Was chaceing a lead there where a nc750 was running out of puff and wouldn’t pull anywhere. Turned out that the clutch was slipping. Why he didn’t say that the engine was revving grand I don’t know. This problem started by the bike loosing power. JJH

Hmm , stop and think. Then think some more . 1) It's a relatively new Honda - unless there was crunch or a bang , it's VERY unlikely to be mechanical. 2.) Spark , again , think about what you have (newish Honda) - modern systems don't tend to just die or give up - BUT , it could be something simple like water in a kill switch , or a dicky sidestand switch - or something "interupting" the sparks. Bikes with dead electrics don't "loose power" - they stop - end of story.
I would be thinking fuel supply problem. You said it was getting fuel ... how on earth do you actually know ? Although I have an NC , I don't know how I would actually check that - try and take fuel tank , fuel valve if there is one ?. breather system and some pipework out of the equation ... by rigging up a separate remote tank (container) fuel supply. Is there a fuel filter in the system ? ... probably is , even though it is 98% sure , not a service item . If so, is it clean. (I would guess it's attached to the pump , so probably in the tank under the seat. A parts diagram would help you find it. I assume you have checked (listened) for fuel pump running with ign on ? (if all is quiet , that could be your problem)

nuff for now .. logic and EXACTLY how it stopped working, is info that needs used to help solve. It will be something simple ....................... good luck , and do let us know.

 

[DrFarkoff]

@JJH

What happened in the 20~30 minutes before it stopped

I am sorry but IF he put fuel in? I get a vibe its diesel OR very bad fuel !!

Wen you say spark did you take the plugs out? or put one in the spark lead externally

Diesel Kills the flame front, even with Easy start DAMHIK

 

[JJH]

Hmm , stop and think. Then think some more . 1) It's a relatively new Honda - unless there was crunch or a bang , it's VERY unlikely to be mechanical. 2.) Spark , again , think about what you have (newish Honda) - modern systems don't tend to just die or give up - BUT , it could be something simple like water in a kill switch , or a dicky sidestand switch - or something "interupting" the sparks. Bikes with dead electrics don't "loose power" - they stop - end of story.
I would be thinking fuel supply problem. You said it was getting fuel ... how on earth do you actually know ? Although I have an NC , I don't know how I would actually check that - try and take fuel tank , fuel valve if there is one ?. breather system and some pipework out of the equation ... by rigging up a separate remote tank (container) fuel supply. Is there a fuel filter in the system ? ... probably is , even though it is 98% sure , not a service item . If so, is it clean. (I would guess it's attached to the pump , so probably in the tank under the seat. A parts diagram would help you find it. I assume you have checked (listened) for fuel pump running with ign on ? (if all is quiet , that could be your problem)

nuff for now .. logic and EXACTLY how it stopped working, is info that needs used to help solve. It will be something simple ....................... good luck , and do let us know.

If it is a fuel issue it should have run on the easy start. JJH

 

[JJH]

@JJH

What happened in the 20~30 minutes before it stopped

I am sorry but IF he put fuel in? I get a vibe its diesel OR very bad fuel !!

Wen you say spark did you take the plugs out? or put one in the spark lead externally

Diesel Kills the flame front, even with Easy start DAMHIK

So I tried easy start. No go. Took out a plug. Spinning the engine over to see if there’s a spark and there was and the bit of easy start that was li the cylinder gave a couple of bangs as well. JJH

 

[JJH]

There is compression the old thumb test so not scientific but I kinda knew anyway because of the way it was turning over. JJH

 

[JJH]

There wasn’t a lot of fuel in it but I put 5 liters in. JJH