1990 60hp, 2nd broken reed set in 4 weeks..why??

[fishfeatures]

I lost approx 2000rpm yesterday while starting to throttle up from trolling for 5 mins.
had a look this evening and the top carb has a broken reed . Almost 4 weeks to the day I had to replace another but at the bottom carb.
Is it common for reed plates to fail ? or is there some other reason like vibration a cause?

I'm lucky as that i have a scrapped motor for spares so I can get it going soon.

I have the silencer on it and no screws,bolts are out of place that can be sucked in...

checked comp and it good on all 3 cylinders, I don't want to tear it down to look for the missing piece as I limped home for about 1/2 hr last night so hopefully the piece has gone out the exhaust

 

[Chinewalker]

Re: 1990 60hp, 2nd broken reed set in 4 weeks..why??

One thing I've seen that can crack reeds is "racing" the engine. I was told by an old-time mech that revving the motor then doing an abrupt slow-down (that 'brrrrrin-din-din-din-din-din...." kind of sound) can "slap" the reeds back into their seats, causing them to crack prematurely... I've seen people do this as part of their normal start-up procedure, thinking it will "warm up" the motor quicker...

 

[fishfeatures]

Re: 1990 60hp, 2nd broken reed set in 4 weeks..why??

One thing I've seen that can crack reeds is "racing" the engine. I was told by an old-time mech that revving the motor then doing an abrupt slow-down (that 'brrrrrin-din-din-din-din-din...." kind of sound) can "slap" the reeds back into their seats, causing them to crack prematurely... I've seen people do this as part of their normal start-up procedure, thinking it will "warm up" the motor quicker...

I always let the motor "warm up" as I park the trailer and load it up with the fishing gear or what ever I have to put in , don't do the "racing" bit but do throttle down abruptly at times if i see a shoal on the fishfinder for example. So maybe it's my style that caused this, I'll keep an eye on how I drive and see if it happens again.

 

[JB]

Re: 1990 60hp, 2nd broken reed set in 4 weeks..why??

Excessive over revving will take them out, as Chinewalker said.

Back in my kart racing days we had to go to entirely different reed plates to get away with running chainsaw engines 10-12Krpm.