cbr250 engine shuts off randomly when clutch pulled in

[Brian P]

I've heard this before but don't really buy it. It's like popping your standard transmission into neutral in a car and coasting to a stop relying entirely on brakes to slow you down. Brakes are cheap. Engine parts are not. The only benefit I can even see to blipping/gearing down in turn is a quick reaction out of a deceleration, but if you know your gears well enough you can easily pop it where you need it and get back at it in the clutch-holding scenario.

Ummm NO.

The benefit that you state is the "only" one also happens to be an EXTREMELY IMPORTANT one.

A manual-transmission car has an H-pattern shifter that can easily be placed into any gear of my choosing at any time and do so directly without going through any other gears. It is also a synchromesh transmission that can readily be put into a gear while stopped. If I'm coming up to a stop and something happens that warrants accelerating away, regardless of which gear it happens to be in at the moment, I'm one stab of the clutch pedal and one non-ambiguous motion of the shifter away from being in second gear (or whatever other gear is appropriate for the road speed).

A motorcycle has a sequential shifter without synchromesh. It is reluctant to shift while stopped. If you are downshifting with clutch pulled in, there is no feedback concerning which gear you should be in, you could easily have downshifted too far or not far enough. It's far better to do the shifts one at a time with audible and visible (on the tach) feedback concerning whether you are in the correct gear or not.

For what it's worth, decelerating with the clutch engaged (back-driving the engine) does not cause any meaningful amount of engine wear (as long as the engine is below redline). The engine is just spinning, it's not under load. The oil pump is running, the water pump is circulating coolant, a film of oil separates all of the moving parts.

[eljay]

OK haven't opined in a while. I've talked to the dealer on the phone, he has to see it to believe it of course. I'm about a week away from my first service already, so I'll show it to them then, assuming I can even do it again. It happened only once this past weekend, and I haven't had time yet to try to replicate the problem on purpose again. If I can't do it, well, I'm going to say it just needed breaking in and everyone who buys a brand new cbr250 be aware... I've been putting a lot of kms on it because I'm just happy as a pig in stink that I have a bike now and just want to ride it in circles around the city. I try to push it a bit when it's safe to do so and am enjoying it.

For those that think working the clutch on the bike is the same as on the car, thanks for trying! Gas clutch shift brake is about all that is the same and you must be from Toronto if you think it's cool to coast in neutral when you are driving. It explains a lot. When I was a kid learning to drive stick my dad told me it was illegal to be in neutral on the road. I doubt that is true, but it forced me to always be in gear anyway. Difference on a bike is there's a friction zone to ease the bike forward, essentially "riding" the clutch that you wouldn't do in a car. But I'm a noob and not a Toronto driver, what do I know?

[toysareforboys]

Sounds good. 2up the manager at the dealership, rip it right to redline and when you get to redline in 4th just drop the throttle and pull in the clutch and I'm sure it'll die on ya every time

Just let the clutch out to fire it back up.

-Jamie M.

[sithlord]

Fellow sufferers, please see here:

http://cbr250rissues.blogspot.com.au/

Trying to see just how often and widespread the problem is.

Please PM me or comment on the website.

[toysareforboys]

Fellow sufferers, please see here:

http://cbr250rissues.blogspot.com.au/

Trying to see just how often and widespread the problem is.

Please PM me or comment on the website.

Make sure you post that on cbr250.net as well

-Jamie M.

[eljay]

I've already hit you with my deets over at cbr250.net thanks man, good effort.

Fellow sufferers, please see here:

http://cbr250rissues.blogspot.com.au/

Trying to see just how often and widespread the problem is.

Please PM me or comment on the website.