hard starting without baffle

[Iahawk]

this is more of an observation than anything...but I'd pulled the baffle out of my slip on muffler on my little Ninja in January. It sounds great with it out, if not just a little too loud. ..but the first time I started it without the baffle I noticed it went from the usual Da-Da-Vroom, an immediate start, to more of a Da-Da-Da-Da-Da, nothing...Da-Da-Da-Da-Da, nothing...and finally Da-Da-Da-Da-Da-Vroom.

I chalked the first slow start up to it sitting, cold, for many weeks. Same thing happened the next time I started it..a  very slow start..and then today I put the baffle back in and it fired right up. Da-Da-Vroom!

So I guess the bike needs a certain amount of back pressure to help it start efficiently? I wasn't expecting such a difference with baffle in vs baffle out.

[Stig / Major Tom]

I love it when old Mr Donfool Widdit teaches me something 🙃

Syig

[CROSSBOLT]

this is more of an observation than anything...but I'd pulled the baffle out of my slip on muffler on my little Ninja in January. It sounds great with it out, if not just a little too loud. ..but the first time I started it without the baffle I noticed it went from the usual Da-Da-Vroom, an immediate start, to more of a Da-Da-Da-Da-Da, nothing...Da-Da-Da-Da-Da, nothing...and finally Da-Da-Da-Da-Da-Vroom.

I chalked the first slow start up to it sitting, cold, for many weeks. Same thing happened the next time I started it..a  very slow start..and then today I put the baffle back in and it fired right up. Da-Da-Vroom!

So I guess the bike needs a certain amount of back pressure to help it start efficiently? I wasn't expecting such a difference with baffle in vs baffle out.

Mixture change regardless of method (analog carb or digital EFI).

[Iahawk]

Mixture change regardless of method (analog carb or digital EFI).

Karl, I would have thought that a fuel injected bike would compensate for the difference? Maybe it's not that smart!

[NorWeWa]

Every EFI has a range it can adjust for. I suspect you are just a bit lean. That's why they sell those EFI tuners.   https://www.dynojet.com/power-commander-fc-for-kawasaki-ex250-europe-only/  Personally I'd put the baffle back in or the stock exhaust. 

Art 

[CROSSBOLT]

Every EFI has a range it can adjust for. I suspect you are just a bit lean. That's why they sell those EFI tuners.   https://www.dynojet.com/power-commander-fc-for-kawasaki-ex250-europe-only/  Personally I'd put the baffle back in or the stock exhaust. 

Well said!

Art

[Iahawk]

yes, my brief hooligan experiment is over, the baffle is in (pic shows baffle in)! Baffle out sounds pretty cool but drones a bit too much at speed, even with ear plugs in. I can't imagine listening to that for an hour or 2 at a time.

Stock muffler weighs about 3x as much and sounds like a scooter...it's been on the shelf in the garage for about 6 years, now. It's staying there!

[NorWeWa]

Scooterpartsco.com sells a Malossi slip on exhaust for my Downtown 300 that I have looked at, feeling it would be nice to get rid of the heavy exhaust, but I don't want my scooter to sound loud at all.  Plus the way I ride I don't really notice any problems with the weight.     https://scooterpartsco.com/index.php?main_page=product_info&cPath=120_3522&products_id=958

Art 

[JJJoseph]

I chalked the first slow start up to it sitting, cold, for many weeks.

This is typical for carbureted machines!  Above 10°C they start effortlessly, but below I have to pray for it to start without a tussle!  But my F/I motos always start first touch every time.

[Iahawk]

This is typical for carbureted machines!  Above 10°C they start effortlessly, but below I have to pray for it to start without a tussle!  But my F/I motos always start first touch every time.

that's the odd thing, my bike is fuel injected and has always started at the touch of the starter button...but not with the baffle out.

[Neil955i]

that's the odd thing, my bike is fuel injected and has always started at the touch of the starter button...but not with the baffle out.

Think you’re on the money with your back pressure theory Hawk.