Water pick up in rudder

[PAUL STIRTON]

I am looking for answers to a problem and was wondering on what side of the rudder blade people put there water pick ups on and how deep below the struts.

Reason. I have a twin SGX-2 90 Boat and it seams to be struggling to pick up water. With the garden hose it pumps water out the water jacket about 1 1/2 inches high so there is no restriction there but when running the boat it has little or no water coming out of the heads. The leading edge of the pickup is past the leading edge of the blade so blow buy is not a issue and the hole is 1 inch below the struts on the right hand side.

Thanks in advance for your feedback.

I have never had this much trouble picking up water before.

 

[Don Ferrette]

I am looking for answers to a problem and was wondering on what side of the rudder blade people put there water pick ups on and how deep below the struts.Reason. I have a twin SGX-2 90 Boat and it seams to be struggling to pick up water. With the garden hose it pumps water out the water jacket about 1 1/2 inches high so there is no restriction there but when running the boat it has little or no water coming out of the heads. The leading edge of the pickup is past the leading edge of the blade so blow buy is not a issue and the hole is 1 inch below the struts on the right hand side.

Thanks in advance for your feedback.

I have never had this much trouble picking up water before.

Paul file the lead in groove deeper on the side of the rudder blade and all the way to the leading edge of the blade, then slightly notch the leading edge. Made a big difference on my CMDi blades. B)

 

[PAUL STIRTON]

I am looking for answers to a problem and was wondering on what side of the rudder blade people put there water pick ups on and how deep below the struts.Reason. I have a twin SGX-2 90 Boat and it seams to be struggling to pick up water. With the garden hose it pumps water out the water jacket about 1 1/2 inches high so there is no restriction there but when running the boat it has little or no water coming out of the heads. The leading edge of the pickup is past the leading edge of the blade so blow buy is not a issue and the hole is 1 inch below the struts on the right hand side.

Thanks in advance for your feedback.

I have never had this much trouble picking up water before.

Paul file the lead in groove deeper on the side of the rudder blade and all the way to the leading edge of the blade, then slightly notch the leading edge. Made a big difference on my CMDi blades. B)

Thanks Don already done that still no water.

 

[Chris Wood]

is the water pick up hole right on the edge of being to high on the water line?? if so that could cause it to surge specially in the corners or when the back end of the boat raise up.

chris

 

[PAUL STIRTON]

is the water pick up hole right on the edge of being to high on the water line?? if so that could cause it to surge specially in the corners or when the back end of the boat raise up.
chris

I was wondering that myself. I am going to put the pick up lower again and on the left side of the blade and see if that makes any difference. I am thinking that there may be a little turbulance coming from the turn fin and messing up the water flow to the rudder blade.

 

[Buckshot]

I have also found that it makes a difference where you put the split in the line to go to each motor. I found that the closer you can get it to the motors before it splits the better.

Another way to check your system would be to hook up your flow meter and flow the line backwards, if it dose not peg the meter out than there is a restriction somewhere.

Please keep us updated about your progress.

Regards,

-Buck-

 

[PAUL STIRTON]

I have also found that it makes a difference where you put the split in the line to go to each motor. I found that the closer you can get it to the motors before it splits the better.Another way to check your system would be to hook up your flow meter and flow the line backwards, if it dose not peg the meter out than there is a restriction somewhere.

Please keep us updated about your progress.

Regards,

-Buck-

Done the flow meter thing and there is no restriction on either motor. I run 2 5/32 Brass tubes one for each engine through the radio box and they are split in the rear compartement. I have run this system on all of my twins before and never had a issue. It is really starting to frustrate me especially since I have now fried 7 motors holes in the piston. They are also still running very rich havn't even started to jump on the needles yet.

 

[Boris Mazor]

I have also found that it makes a difference where you put the split in the line to go to each motor. I found that the closer you can get it to the motors before it splits the better.Another way to check your system would be to hook up your flow meter and flow the line backwards, if it dose not peg the meter out than there is a restriction somewhere.

Please keep us updated about your progress.

Regards,

-Buck-

I always flow the cooling system with my flow meter. If the numbers close to 20 mm this is O.K. If the numbers more than 25 mm - try to find way! Good luck. Boris.

 

[AndyBrown]

I have also found that it makes a difference where you put the split in the line to go to each motor. I found that the closer you can get it to the motors before it splits the better.Another way to check your system would be to hook up your flow meter and flow the line backwards, if it dose not peg the meter out than there is a restriction somewhere.

Please keep us updated about your progress.

Regards,

-Buck-

Done the flow meter thing and there is no restriction on either motor. I run 2 5/32 Brass tubes one for each engine through the radio box and they are split in the rear compartement. I have run this system on all of my twins before and never had a issue. It is really starting to frustrate me especially since I have now fried 7 motors holes in the piston. They are also still running very rich havn't even started to jump on the needles yet.

Paul,

Did you flow the system starting at the engines and back all the way through the rudder blade?

What are the head temps after a hard run?

Burning holes in pistons is not normally caused by lack of cooling. Burning holes in pistons is however, easy to do in a twin if the engines are not loaded with enough prop and the engines are too lean.

With props that are too small the engines will sound rich even though they are far too lean, but unlike a single engine boat the massive power of the twins will keep running and not show the lean sag until it's far too late.

I've seen this many times.

 

[SayMikey]

I have also found that it makes a difference where you put the split in the line to go to each motor. I found that the closer you can get it to the motors before it splits the better.Another way to check your system would be to hook up your flow meter and flow the line backwards, if it dose not peg the meter out than there is a restriction somewhere.

Please keep us updated about your progress.

Regards,

-Buck-

Done the flow meter thing and there is no restriction on either motor. I run 2 5/32 Brass tubes one for each engine through the radio box and they are split in the rear compartement. I have run this system on all of my twins before and never had a issue. It is really starting to frustrate me especially since I have now fried 7 motors holes in the piston. They are also still running very rich havn't even started to jump on the needles yet.

Paul,

Did you flow the system starting at the engines and back all the way through the rudder blade?

What are the head temps after a hard run?

Burning holes in pistons is not normally caused by lack of cooling. Burning holes in pistons is however, easy to do in a twin if the engines are not loaded with enough prop and the engines are too lean.

With props that are too small the engines will sound rich even though they are far too lean, but unlike a single engine boat the massive power of the twins will keep running and not show the lean sag until it's far too late.

I've seen this many times.

Does it flow good water when turning? I have a cat with the rudder water slot on the wrong side and it wont water in the straight away. Pretty sure you want the slot inside by the prop

 

[moparbarn]

paul, search on the general rc boating forum, under" speedmaster rudder" - water inlet side, thread by raydee B) .

 

[PAUL STIRTON]

I have also found that it makes a difference where you put the split in the line to go to each motor. I found that the closer you can get it to the motors before it splits the better.Another way to check your system would be to hook up your flow meter and flow the line backwards, if it dose not peg the meter out than there is a restriction somewhere.

Please keep us updated about your progress.

Regards,

-Buck-

Done the flow meter thing and there is no restriction on either motor. I run 2 5/32 Brass tubes one for each engine through the radio box and they are split in the rear compartement. I have run this system on all of my twins before and never had a issue. It is really starting to frustrate me especially since I have now fried 7 motors holes in the piston. They are also still running very rich havn't even started to jump on the needles yet.

Paul,

Did you flow the system starting at the engines and back all the way through the rudder blade?

What are the head temps after a hard run?

Burning holes in pistons is not normally caused by lack of cooling. Burning holes in pistons is however, easy to do in a twin if the engines are not loaded with enough prop and the engines are too lean.

With props that are too small the engines will sound rich even though they are far too lean, but unlike a single engine boat the massive power of the twins will keep running and not show the lean sag until it's far too late.

I've seen this many times.

Andy did all the normal checks and the engines are flowing rich 30 on one of boris mazors meters. same engines and mixture controls in another twin not a problem.

I think I may have however found a problem with the oil i'm using as it seems to be breaking down as after I HAVE PULLED ONE OF THE MOTORS APART I have found the crank rod and wrist pin are blue from heat and that is not a water issue. I still however have a water issue as the faster I go the less water coming out. Andy the props are two of yours 1667 cupped at 6 inches

 

[ALLAN YUEN]

h34r: Which one CMB90 HR or RS? what size CMDI rudder blader 1.0" or 1.1" ? I can tell two size blade sample: 1.0 only small hole 1/16"( 1.55mm) and 1.1" only bit of big hole 5/64" (1.95mm) drill 3/32" (2.35mm) for water jacket headed better waterflow out If you check on blade hole size 1/16 so drill 5/64" be careful easy break

Hope this help Allan

 

[AndyBrown]

I have also found that it makes a difference where you put the split in the line to go to each motor. I found that the closer you can get it to the motors before it splits the better.Another way to check your system would be to hook up your flow meter and flow the line backwards, if it dose not peg the meter out than there is a restriction somewhere.

Please keep us updated about your progress.

Regards,

-Buck-

Done the flow meter thing and there is no restriction on either motor. I run 2 5/32 Brass tubes one for each engine through the radio box and they are split in the rear compartement. I have run this system on all of my twins before and never had a issue. It is really starting to frustrate me especially since I have now fried 7 motors holes in the piston. They are also still running very rich havn't even started to jump on the needles yet.

Paul,

Did you flow the system starting at the engines and back all the way through the rudder blade?

What are the head temps after a hard run?

Burning holes in pistons is not normally caused by lack of cooling. Burning holes in pistons is however, easy to do in a twin if the engines are not loaded with enough prop and the engines are too lean.

With props that are too small the engines will sound rich even though they are far too lean, but unlike a single engine boat the massive power of the twins will keep running and not show the lean sag until it's far too late.

I've seen this many times.

Andy did all the normal checks and the engines are flowing rich 30 on one of boris mazors meters. same engines and mixture controls in another twin not a problem.

I think I may have however found a problem with the oil i'm using as it seems to be breaking down as after I HAVE PULLED ONE OF THE MOTORS APART I have found the crank rod and wrist pin are blue from heat and that is not a water issue. I still however have a water issue as the faster I go the less water coming out. Andy the props are two of yours 1667 cupped at 6 inches

Paul,

If it's losing water at high speeds, it may be that the leading edge is too blunt. This can blow a big hole in the water that will surpass the p/u hole. Work it with a file and get it as sharp as possible.

 

[PAUL STIRTON]

I have also found that it makes a difference where you put the split in the line to go to each motor. I found that the closer you can get it to the motors before it splits the better.Another way to check your system would be to hook up your flow meter and flow the line backwards, if it dose not peg the meter out than there is a restriction somewhere.

Please keep us updated about your progress.

Regards,

-Buck-

Done the flow meter thing and there is no restriction on either motor. I run 2 5/32 Brass tubes one for each engine through the radio box and they are split in the rear compartement. I have run this system on all of my twins before and never had a issue. It is really starting to frustrate me especially since I have now fried 7 motors holes in the piston. They are also still running very rich havn't even started to jump on the needles yet.

Paul,

Did you flow the system starting at the engines and back all the way through the rudder blade?

What are the head temps after a hard run?

Burning holes in pistons is not normally caused by lack of cooling. Burning holes in pistons is however, easy to do in a twin if the engines are not loaded with enough prop and the engines are too lean.

With props that are too small the engines will sound rich even though they are far too lean, but unlike a single engine boat the massive power of the twins will keep running and not show the lean sag until it's far too late.

I've seen this many times.

Andy did all the normal checks and the engines are flowing rich 30 on one of boris mazors meters. same engines and mixture controls in another twin not a problem.

I think I may have however found a problem with the oil i'm using as it seems to be breaking down as after I HAVE PULLED ONE OF THE MOTORS APART I have found the crank rod and wrist pin are blue from heat and that is not a water issue. I still however have a water issue as the faster I go the less water coming out. Andy the props are two of yours 1667 cupped at 6 inches

Paul,

If it's losing water at high speeds, it may be that the leading edge is too blunt. This can blow a big hole in the water that will surpass the p/u hole. Work it with a file and get it as sharp as possible.

Thanks Andy I will give that a try. The blade is reasonably sharp thou but I will make it like a razor.

 

[Mike Nowicki]

I have also found that it makes a difference where you put the split in the line to go to each motor. I found that the closer you can get it to the motors before it splits the better.Another way to check your system would be to hook up your flow meter and flow the line backwards, if it dose not peg the meter out than there is a restriction somewhere.

Please keep us updated about your progress.

Regards,

-Buck-

Done the flow meter thing and there is no restriction on either motor. I run 2 5/32 Brass tubes one for each engine through the radio box and they are split in the rear compartement. I have run this system on all of my twins before and never had a issue. It is really starting to frustrate me especially since I have now fried 7 motors holes in the piston. They are also still running very rich havn't even started to jump on the needles yet.

Paul,

Did you flow the system starting at the engines and back all the way through the rudder blade?

What are the head temps after a hard run?

Burning holes in pistons is not normally caused by lack of cooling. Burning holes in pistons is however, easy to do in a twin if the engines are not loaded with enough prop and the engines are too lean.

With props that are too small the engines will sound rich even though they are far too lean, but unlike a single engine boat the massive power of the twins will keep running and not show the lean sag until it's far too late.

I've seen this many times.

Andy did all the normal checks and the engines are flowing rich 30 on one of boris mazors meters. same engines and mixture controls in another twin not a problem.

I think I may have however found a problem with the oil i'm using as it seems to be breaking down as after I HAVE PULLED ONE OF THE MOTORS APART I have found the crank rod and wrist pin are blue from heat and that is not a water issue. I still however have a water issue as the faster I go the less water coming out. Andy the props are two of yours 1667 cupped at 6 inches

Paul,

If it's losing water at high speeds, it may be that the leading edge is too blunt. This can blow a big hole in the water that will surpass the p/u hole. Work it with a file and get it as sharp as possible.

Thanks Andy I will give that a try. The blade is reasonably sharp thou but I will make it like a razor.

Paul,

If the oil is not working, then maybe it's heating to fast and forming a steam vapor-lock

 

[John Finch]

I have also found that it makes a difference where you put the split in the line to go to each motor. I found that the closer you can get it to the motors before it splits the better.Another way to check your system would be to hook up your flow meter and flow the line backwards, if it dose not peg the meter out than there is a restriction somewhere.

Please keep us updated about your progress.

Regards,

-Buck-

Done the flow meter thing and there is no restriction on either motor. I run 2 5/32 Brass tubes one for each engine through the radio box and they are split in the rear compartement. I have run this system on all of my twins before and never had a issue. It is really starting to frustrate me especially since I have now fried 7 motors holes in the piston. They are also still running very rich havn't even started to jump on the needles yet.

Paul,

Did you flow the system starting at the engines and back all the way through the rudder blade?

What are the head temps after a hard run?

Burning holes in pistons is not normally caused by lack of cooling. Burning holes in pistons is however, easy to do in a twin if the engines are not loaded with enough prop and the engines are too lean.

With props that are too small the engines will sound rich even though they are far too lean, but unlike a single engine boat the massive power of the twins will keep running and not show the lean sag until it's far too late.

I've seen this many times.

Andy did all the normal checks and the engines are flowing rich 30 on one of boris mazors meters. same engines and mixture controls in another twin not a problem.

I think I may have however found a problem with the oil i'm using as it seems to be breaking down as after I HAVE PULLED ONE OF THE MOTORS APART I have found the crank rod and wrist pin are blue from heat and that is not a water issue. I still however have a water issue as the faster I go the less water coming out. Andy the props are two of yours 1667 cupped at 6 inches

Paul,

If it's losing water at high speeds, it may be that the leading edge is too blunt. This can blow a big hole in the water that will surpass the p/u hole. Work it with a file and get it as sharp as possible.

Thanks Andy I will give that a try. The blade is reasonably sharp thou but I will make it like a razor.

Paul,

If the oil is not working, then maybe it's heating to fast and forming a steam vapor-lock

I had a similar problem last year with a boat and could not make sense of it no matter what I did. I put a second hole in the rudder from the other side of where the pickup was, which gave me water flow to the engine no matter what position the rudder was in. Bacically the entrance hole was then on both sides of the rudder. The problem went away. I never had a problem like that before and never did find out why, but the solution worked. Still scratching my head.

 

[Terry Keeley]

I had a similar problem last year with a boat and could not make sense of it no matter what I did. I put a second hole in the rudder from the other side of where the pickup was, which gave me water flow to the engine no matter what position the rudder was in. Bacically the entrance hole was then on both sides of the rudder. The problem went away. I never had a problem like that before and never did find out why, but the solution worked. Still scratching my head.

Been doing that myself for 20+ years after I noticed I was getting water starved in the corners.

Not any more...

 

[tnrcboatracer]

Try a temporary water PU at the inside rear of the left sponson (if the bait us an SGX, it needs to go on hte onside edge of the sponson. if the rear face of hte sponson is flat, the tube can be mounted there. I laos have a trick way to run the water through the boom tube.). If the sponson PU works for you, you can then use 440 SS knife blades for the rudder. But watch out, you can get a nasty cut.

 

[Terry Keeley]

Paul,If the oil is not working, then maybe it's heating to fast and forming a steam vapor-lock

I've seen this too if the flow is interrupted some way, the motor gets hot and won't pass any more water because of the steam.