Hi, my husband recently bought a 349 and relocated the condenser to under the tank. Seem to have an issue with water ingress to the magneto area after riding burn sections at a recent trial.

He's sealed the magneto casing using instant gasket but water still managed to get in.

Thinking of just drilling a hole at the bottom of the casing to let the water escape. Any comments or suggestions would be appreciated.

Cheers, Fiona

It might not be water getting in but condensation not getting out we used to put a breather on top of the casing with rubber tube routed higher up the frame use to stop moisture getting between the points 

Thanks, but it's already got that fitted. Water lying in casing was dirty (muddy coloured).

 

Yes it is good to make a drain hole. Whatever way the water gets in, by condensation or by getting sucked in with the cooling effect of the warm casing going under water, a drain hole will allow the liquid water to drain out. I use both a vent and a drain on my magneto casings. I usually make a plain hole about 5mm diameter in a place that is unlikely to be blocked by debris.

Depending on how free-flowing the vent system is and how cold the water is in the creek, some water may be drawn in through the drain, but of course any water drains straight back out again.

The only weakness with the drain concept is that if the bike engine is submerged for a long time, the casing will fill up, whereas if there is only a vent it will suck a bit in, then stop filling.

It is good practice to remove or loosen the magneto cover after a wet ride or after washing the bike so that it drys out fully inside, even if there is a drain and a vent, to minimise corrosion.

Edited January 13, 20188 yr by feetupfun

6 hours ago, fiona said:

Hi, my husband recently bought a 349 and relocated the condenser to under the tank. Seem to have an issue with water ingress to the magneto area after riding burn sections at a recent trial.

He's sealed the magneto casing using instant gasket but water still managed to get in.

Thinking of just drilling a hole at the bottom of the casing to let the water escape. Any comments or suggestions would be appreciated.

Cheers, Fiona

On 247's you often find the inside of the casing damaged from the kick-starter over travel allowing water to get in, might be worth having a look.

An old practice used on the bell housing of farm tractors, and applicable to the magneto housing, is to install a small cotter pin in the drain hole. The jiggling effect of the cotter pin will prevent the hole from becoming plugged.

 

On ‎1‎/‎15‎/‎2018 at 2:57 AM, nh014 said:

An old practice used on the bell housing of farm tractors, and applicable to the magneto housing, is to install a small cotter pin in the drain hole. The jiggling effect of the cotter pin will prevent the hole from becoming plugged.

 

That's clever have seen that before,IMO its a good remedy for this problem,well done.

On 14/1/2018 at 2:26 AM, oldaz said:

On 247's you often find the inside of the casing damaged from the kick-starter over travel allowing water to get in, might be worth having a look.

That's also applicable to 349s

On 14/01/2018 at 7:56 AM, fiona said:

Thanks, but it's already got that fitted. Water lying in casing was dirty (muddy coloured).

 

Have you figured out how/where the water got in there yet? I wouldn't be drilling the drain hole unless there's no way to stop the water getting in there in the first place. I had a drain hole (with cotter pin) in the tractor clutch housing and it does work, but then I didn't drive it through streams or other deep water very often.

If the PO didn't have a breather tube fitted and plunged a hot bike into a cold stream, water could get in through the breather, through a non-sealed cover gasket or cracks in the cover or through damage caused by kick start over travel. Can't see any other way muddy water could get in there.