What are the SYMPTONS of Reed failure?

[Super Dragpack]

What are the symptons of 'bad' or 'stuck' reeds please?

In particular, in connection with a 1972 Mercury 80hp 4 Cylinder would be nice - but its good to know for any engine.

Thanks in advance.

 

[achris]

Re: What are the SYMPTONS of Reed failure?

Mostly a really rough idle (That can be said for most 2 strokes anyway ).
The best is 'spitting' back through the carb throat..... If you put you hand close you'll feel it pushing and pulling your hand, it should just pull it....

Chris...........

 

[donzi gt230]

Re: What are the SYMPTONS of Reed failure?

If you do the 'put your hand close' test be careful to not let it suck onto the carb. Lots of vacuum can leave a nasty injury, seen it!

 

[444]

Re: What are the SYMPTONS of Reed failure?

Someone else told me that weak reeds can lean out the upper cylinder fed by each carb. Said a way to test was to do a 30 second full throttle blast, shut off and look at the plugs to see if the upper cylinder is running lean compared ot the lower.

 

[Faztbullet]

Re: What are the SYMPTONS of Reed failure?

No such thing as "weak reeds" either good or bad and made of spring steel. Broken or chipped reeds will cause: idle problem,spitting back thru carb,fluttering noise from carb,bad hole shot, etc...

 

[Fuzzytbay]

Re: What are the SYMPTONS of Reed failure?

Someone else told me that weak reeds can lean out the upper cylinder fed by each carb. Said a way to test was to do a 30 second full throttle blast, shut off and look at the plugs to see if the upper cylinder is running lean compared ot the lower.

Good thing you found this site.........isn't it?

 

[Super Dragpack]

Re: What are the SYMPTONS of Reed failure?

So they won't affect starting then?

 

[sschefer]

Re: What are the SYMPTONS of Reed failure?

So they won't affect starting then?

Yes they will effect starting. The symptom will be hard start and the need for excessive choke. Once started there will be excessive smoke but the motor running off idle will probably be normal.

There is a standard for testing reeds in the Merc Service Manual. It's even in the Seloc Manual. It's a pretty effective method and keeps you from replacing reeds when you really don't need to.

 

[j_martin]

Re: What are the SYMPTONS of Reed failure?

Yes they will effect starting. The symptom will be hard start and the need for excessive choke. Once started there will be excessive smoke but the motor running off idle will probably be normal.

There is a standard for testing reeds in the Merc Service Manual. It's even in the Seloc Manual. It's a pretty effective method and keeps you from replacing reeds when you really don't need to.

It's in the book. Go figure.

 

[coolguy147]

Re: What are the SYMPTONS of Reed failure?

fluttering sound?? what do you mean by that?

 

[achris]

Re: What are the SYMPTONS of Reed failure?

fluttering sound?? what do you mean by that?

If you have a good ear you can actually hear the carb 'fluttering', as the air is sucked and then blown through the throat.... Sort of sounds like 'fuffing'...

Chris......

 

[Super Dragpack]

Re: What are the SYMPTONS of Reed failure?

Yes they will effect starting. The symptom will be hard start and the need for excessive choke. Once started there will be excessive smoke but the motor running off idle will probably be normal.

There is a standard for testing reeds in the Merc Service Manual. It's even in the Seloc Manual. It's a pretty effective method and keeps you from replacing reeds when you really don't need to.

Those are the exact symptons I have, although my plugs are also almost always wet (with fuel). It will sometimes start well but will then bog itself down and refuse to start again for a while. If I remove and clean the plugs it does seem to start again a little quicker.

It seems a little more than mixture to me. What do you think?

 

[Super Dragpack]

Re: What are the SYMPTONS of Reed failure?

Bump

Any suggestions guys please?

 

[HD Fatboy?]

Re: What are the SYMPTONS of Reed failure?

I am new here but if I was you I would start with what was already poted.

Yes they will effect starting. The symptom will be hard start and the need for excessive choke. Once started there will be excessive smoke but the motor running off idle will probably be normal.

There is a standard for testing reeds in the Merc Service Manual. It's even in the Seloc Manual. It's a pretty effective method and keeps you from replacing reeds when you really don't need to.

 

[blazer01]

Re: What are the SYMPTONS of Reed failure?

What are the symptons of 'bad' or 'stuck' reeds please?

In particular, in connection with a 1972 Mercury 80hp 4 Cylinder would be nice - but its good to know for any engine.

Thanks in advance.

Well for starters if you have a metal reed and it breaks more than likelly it's gonna get sucked into the cylinder that is going up and very well possible detonite your engine.

Secondlly fuel consumption will gradually weaken. Another could be hard starts( cold or hot)

 

[Super Dragpack]

Re: What are the SYMPTONS of Reed failure?

I have gone through everything but still have almost impossible starts. Occasionally it will start and run at high idle (2000rpm) but will not run lower and with often cut out for no reason and then not restart.

When it does run it smokes a lot and is very unstable (surging etc). It has not been running long enough to run all the checks but it does pump water (thank goodness) but I have no idea if its spitting fuel out the carbs. When I look into the carbs though, they are all wet inside, even right to the very end of the carb mouth.

I have double and triple checked everything else (I work on engines full time, so hope I haven't missed anything stupid), but the symptons never change.

After 38 years and about 5-10 years being stood, will the reeds be at the end of their natural life? Can I just flip them over?

I have another engine here for spares and most of the reeds on that engine are stuck open a little.

 

[blazer01]

Re: What are the SYMPTONS of Reed failure?

I have gone through everything but still have almost impossible starts. Occasionally it will start and run at high idle (2000rpm) but will not run lower and with often cut out for no reason and then not restart.

When it does run it smokes a lot and is very unstable (surging etc). It has not been running long enough to run all the checks but it does pump water (thank goodness) but I have no idea if its spitting fuel out the carbs. When I look into the carbs though, they are all wet inside, even right to the very end of the carb mouth.

I have double and triple checked everything else (I work on engines full time, so hope I haven't missed anything stupid), but the symptons never change.

After 38 years and about 5-10 years being stood, will the reeds be at the end of their natural life? Can I just flip them over?

I have another engine here for spares and most of the reeds on that engine are stuck open a little.

for starters i would look into buying a rebuild kit for your carbs and call chris and order a set of reeds from this web site..............http://www.chriscarsonmarine.com/reed-valves.htm

 

[Super Dragpack]

Re: What are the SYMPTONS of Reed failure?

We have just pulled the motor apart again to check the reed valves. I am upset to see that visually they don't seem bad. Some are open very slightly and you can see light through most, but is this enough to cause a problem?

 

[blazer01]

Re: What are the SYMPTONS of Reed failure?

We have just pulled the motor apart again to check the reed valves. I am upset to see that visually they don't seem bad. Some are open very slightly and you can see light through most, but is this enough to cause a problem?

yes i just put a new set of chris carson reeds on mine and there is no gap

 

[achris]

Re: What are the SYMPTONS of Reed failure?

... Can I just flip them over?....

DEFINITELY NOT!!!

Do you have a service manual (not a clymer or seloc, a real one)???

Reeds can hang open a little. The spec is 7 thou for that engine...

Chris..........