What's wrong here ?

[Spongefinger]

Hi Guys , Tried starting my hornet today and things don't seem right. I've not started it for two weeks just popped to give her a turnover. I usual routine, fuel switch on ( yes there's plenty of petrol) choke on full started first push left for 5 mins to warm up. I then went to turn choke down and ever after turning down just a little bit the bike stalled. Restarted with chole on and revs flew to 4000 rpm. Lowed choked a bit and it held for a while then slowly died and stalled. Started again this time I held it at 2500rpm on the throttle. I didn't adjust at all as the revs slowly went down and the bike stalled. If you twist the throttle the revs go up fine but it won't idle just stalls.

 

In this video I had already started the bike once  this was not a cold start.

 

I know very little about mechanical side of bikes so any advice appreciated. 

 

I have attached a video so you can see and hear .

 

 

 

 

[Mississippi Bullfrog]

How long have you had it, like how well do you know it's habits when starting from cold? Some engines can be fussy on choke. I've found that once it's started I hold the throttle to warm it up and close the choke fairly quickly. 

 

It's not easy to tell off a video but it sounds like it's just in that fussy area between having started but not warmed up enough to idle without a touch of throttle.

[Spongefinger]

Cheers, 

 

   I 've only had it a month and because of work commitments not be on it much at all hopefully that's the case that , it's my first bike I'm just not used to the eccentricities of my bikes choke. Fingers crossed that's it  

[billy sugger]

If it is a carbed model, and I assume it is due to manual choke, your slow running jet needs cleaning out. 4000rpm means the main jet has took over feeding fuel to the engine, and, as the choke enriches the mixture its counteracting the blockage at low revs/tickover. The lumpiness at 2500 rpm is the engine hunting for fuel to keep running

[PaulCa]

Work with it a while.  Let it rev up a bit, not much.  I found starting up the biffer after a cold rest up, it would start on some cylinders, not others, cough, grumble, labour, stall and be a right princess, and it's fuel injected.  I would just tickle it to keep it running until it smoothed out, usually followed by steam from the exhausts for a while.

 

Just play the choke / throttle game, trying to keep it running aiming to let it run on it's own, then let it warm up properly and see how it it.  If you can't keep it running.  Check the obvious, like no funny mates have swapped your plug leads around.  Leaks, water in the fuel.  Mouse in the airbox, those kind of things.

[PaulCa]

2 hours ago, Spongefinger said:

Cheers, 

 

   I 've only had it a month and because of work commitments not be on it much at all hopefully that's the case that , it's my first bike I'm just not used to the eccentricities of my bikes choke. Fingers crossed that's it  

 

Choked/carb bikes can be complete divas at cold start.  You'll learn it's little ways, but as you have no reference I understand it's difficult to know when it just needs a bit more working or if something is wrong.

One thing I would say, until you have comfortable with how it behaves cold on choke, avoid riding it until it will idle off the choke.  I have had some pretty scary "choke" incidents.  Usually a bogging down in traffic followed by a massive surge because I just held the throttle open and waited.  Lessons you learn while shiny side are the best ones.

 

As Billy points out.  Poor behaviour on the choke can be a sign of other issues.

Edited October 15, 2021 by PaulCa

[Mississippi Bullfrog]

4 hours ago, Spongefinger said:

Cheers, 

 

   I 've only had it a month and because of work commitments not be on it much at all hopefully that's the case that , it's my first bike I'm just not used to the eccentricities of my bikes choke. Fingers crossed that's it  

I would suggest that if the bike is new to you it's worth just giving yourself time to get used to its foibles before taking things to bits.

 

Every carbed bike I've had has been unique when needing choke. I always warm the engine before riding off, I never set off whilst it still needs choke.

[PaulCa]

Random memory, the KLE500.  Commuting during winter, I used to give it full choke, let it rev up to 4k (it didn't go much higher and it would sit there in traffic for an hour soon anyway!) and let it sit there until I was ready all buttons done up and then drop the choke out completely.   It would usually idle and be workable with after that.  See the comment below though.   Consider... When you get into the car on a cold day, it too (electronic fuel injection) will hold a high or very high idle on first start up.  To offset the low idle stability at low rpm of the cold engine.

 

If a cold engine cuts power on you, also cut the throttle.  Your right hand will instinctively continue to wind on looking for the response it expects.  Then the engine recovers, and suddenly all the power comes back and you are at 100% throttle.  PING!  I did that mistake on small bikes thankfully and only tyres were harmed. 

 

Think about a cold engine like a mate your just woke up.  Tread carefully.  It has things in reach to throw at you and it can always hit SNOOZE in traffic.