Running on - damaging?

[Speedy88]

Hey guys, the 360 has been great so far. But when it shuts off, the revs will die until 0rpm where it will cough and splutter a few more times before fully stopping.

Also scarily, it sounds like it starts to run backwards. I just wondered if any of this is damaging to the engine as I'd be happy to just live with it for now until I get an engine conversion done.

Cheers guys

[Evoman]

Hey guys, the 360 has been great so far. But when it shuts off, the revs will die until 0rpm where it will cough and splutter a few more times before fully stopping.

Also scarily, it sounds like it starts to run backwards. I just wondered if any of this is damaging to the engine as I'd be happy to just live with it for now until I get an engine conversion done.

Cheers guys

How did you figure that out? lol Im not sure it would, and I cant see how it would change direction once started

[frazeb]

a leaky inlet sometimes makes your revs drop and cough and splutter

[Bodyman]

As far as i know, a 4 stroke won't run backwards!

Check your carb mounting face for air leaks.

Shouldnt be catastrophically damaging, though.

[Speedy88]

Kewl, cheers fellas. It just makes a sound sometimes like it's running (revs go up a bit) but it sounds totally different, maybe its just spinning without combustion.

[sven360]

If it's running on the ignition is too far advanced.

A high spec competition engine can throw a rod in this condition but std will be OK though it sounds bad.

[valman]

mine runs backwards sometimes after switching off (i turn the car off and leave it in 1st and let the clutch up as i switch it off and it actually drives in reverse so it it possible!) ive read that its very bad for the engine, and like said above it is caused by the ignition timing. although a bit of fettling sorted it out now and it switches off nicely *touch wood*

[jtbo]

But how ignition timing would have anything to do with it when you switch it off as certainly when switched off there will be no sparks with 360 that has renix unit as there is no brain on to tell when to shoot?

Starting engine by reversing and lifting clutch up while on 1st gear is certainly possible in 1978 Ford that parents had at 80's and I'm sure it was 4stroke.

There needs to be few conditions that meet to get that running after switching off, mine did it too. Most importantly there must be air leak, with air leak most likely carb is set differently, so that idle cutoff solenoid has no longer much effect, also some carbon buildup in engine is usually needed. Petrol is self igniting because of heat and as there is air leak there is enough air to make it burn too.

When there is air leak, carb is usually set so that it has richer mixture, which allows enough rich mixture to be sucked from the intake.

Also if idle cutoff solenoid is not original condition and working properly it causes issue too or at least help making it.

My carb base was badly warped, there was no good seal between carb and intake, so it did cause lot of odd things, carb mounting screws can be tightened to only 2Nm or base will warp, even with 360, so that can cause it, also throttle butterfly shaft can be caused wear to axle housing causing leak, yet intake gasket can be bad or even intake manifold to head surface warped, but I guess that is rare.

Most of this is for B200K solex carb version of 360 of course.

Cheap and easy solution is to put 5th and lift the clutch while standing on brake

[Speedy88]

Turned out to be idle speed, cheers all