1/2 inch strainer on a 3/8 inch line any problems?

amk
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1/2 inch strainer on a 3/8 inch line any problems?

Post by amk »

I looked around and all I could find were 1/2 inch strainers from jabsco. So what I did was just have a reducer to hook from the 3/8 to the half inch hose about 6 inches to the strainer then another 6 inches of 1/2 inch hose on the outlet to another reducer back to the 3/8" then into the motor this set up wouldn't cause any problems right? It should flow and just maybe have a airpocket in the strainer? I've since found a 3/8 inch strainer on protec website but Im $50 into 1/2 inch jabsco strainers since I ordered another for a parallel set up.

CedarRiverScooter
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1/2 inch strainer on a 3/8 inch line any problems?

Post by CedarRiverScooter »

The oversize hose won't be a problem at all. If it was the other way around, it might restrict the designed flow, but your good to go IMO.

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amk
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1/2 inch strainer on a 3/8 inch line any problems?

Post by amk »

I didn't think so I was just having a overheating problem I guess I need to pull the head and see if something is in that jacket.

bellman
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1/2 inch strainer on a 3/8 inch line any problems?

Post by bellman »

The strainer shouldn't cause any issues. A big concern with inline strainers to keep in mind is that they supply clean water ONLY when clean. If you use one in sandy waters you may find that you have to clean the often. If you don't realize it's clogged, the filter can actually be the reason you overheat. Most jetski motors will digest and eject sandy water w/o issue so just be sure to check it frequently. The safest way to know that you have cooling is to have a very visible pisser. As long as its flowing you have water. If it stops, stop ASAP and figure out what the problem is. The other thing that is probably the best way to insure your cooling system stays clear is to back flush through the pisser. Regular head mounted flush kits will miss lots of shells, small pebbles, and other small debris. If you're using dual cooling and have two pissers, just cover one with your finger while you flush the other. If you're running in clear fresh water, don't bother flushing as you don't need to at all. Just blow out the motor very well by running it for 15-30 seconds out of water while blipping the motor wide open on and off. Let it get good and hot to dry it out well. Do this even if you do flush the motor.

Charles

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1/2 inch strainer on a 3/8 inch line any problems?

Post by PSG-1 »

Another way to know if the strainer clogs and flow is reduced to the engine is to install an outboard water pressure gage. Be sure to install it between the strainer and the engine, not between the pump and the strainer. Reason being is that if it's between the pump and the strainer and it clogs, it will continue to read pressure even though there's no flow to the engine. With the T fitting located between the strainer and engine, the instant it clogs, your PSI reading will drop. Running 1/2" lines, mine reads around 10 PSI at cruising speed, and around 15 PSI at full throttle.

It's important to note where your normal operating PSI is, so you can detect when something isn't right. If you see a drop in PSI, you've got a clog in the strainer, or somewhere between there and the pump. But if you ever see a RISE in the pressure, this is an indication of a collapsed or pinched cooling hose, or a restriction in the engine, such as sand or shells blocking cooling passages (which hopefully, the strainer will prevent)

On a final note, since I run a Jabsco strainer on my boat as well, I can tell you that the fine mesh screen that comes with the 1/2" model is entirely too small for jet boating, it will quickly load with the smallest of debris that can easily pass through the engine without problems.
100_0620.JPG
The larger mesh screen that comes with the 3/4" model is more appropriate, as it is slightly more coarse, and will allow fine sediment to pass through, but will stop pieces of shells or tiny bits of gravel and other such debris that could jam up in the cooling passages. As you can see in the pic, I have mine mounted right next to my seat, on the front side of the rear deck. This way, I can actually see the water going to my engine at a glance, and I know if I need to stop the boat and clean the screen. And in the left corner of the pic is my flush fitting, so everything is right where I need it.
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bellman
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1/2 inch strainer on a 3/8 inch line any problems?

Post by bellman »

You're right on with screen size. I've got a new 3/8" barbed fitting strainer out in the shop if the OP wants it. Just P.M. me your address and you can have it. McMaster Carr has stainless filter screen material in many mesh sizes in small pieces if you wanted to roll a piece yourself with a larger sieve size. As long as your flush (can't tell in pic) comes in where the last water line that exits the motor goes out, you're actually getting a good backflush. Personally, FWIW(probably not much :D ) , I'd install the pressure gauge downstream of the motor. The reason is, that like you were saying about putting it between the pump and strainer, it's possible to have water making it to the motor, but not making it out the other side. I think it would be unlikely and you'd probably notice it on your gauge, but I've seen so many freak things lock up motors that almost nothing would surprise me. On yamaha pumps, the cooling line boss/fitting on the pump has a feeze plug looking disc on the side that can pop out. It's really rare, but if you lose cooling and cant find a clog, it's worth looking there. The water takes the easy path straight out and not much makes it to the motor. I think using a pressure gauge is a good idea, but it wouldnt have been possible to watch on a standup. My riding buddy once rode one of my stroker skis with a single 1/2" cooling line and didn't notice the pisser had stopped flowing. He rode it long enough that when he stopped, the motor was so hot that the barbed water fittings on the head had melted through the cooling lines :shock: ? The perimeter oring on the head had gotten so hot that it had melted and started to run down the side of the cylinder. The incoming cooling line had come off. Thankfully it was a race gas motor with 32:1 castor and shockingly didn't hurt anything. Not so much as a scratch in the cross hatching on the cyl walls New orings and reconnecting all the cooling lines got everything fixed. He watches pissers now 8) .

amk
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1/2 inch strainer on a 3/8 inch line any problems?

Post by amk »

My boat has a visible pisser and when it over heats there's still flow it just has steam mixed in. When I first got my boat back and running after I re did it I ran it on the river when it was really low. I was still getting used to the stick and I pretty much ran it over a sandy rock bar more than once before I had the strainer. I had to float back to the ramp because I lost cooling flow totally. I used an air compressor to blow the lines but it just seems to run hoter now. The other day when I had it in the bay it ran fine but I went home put it on the river to flush with fresh water and it got hot and would predetonate fuel every five minutes if I didn't stop and let it cool. The river was high and had lots of small sticks and debris from all the rain here in Texas recently but I didn't see much on the strainer. Could of been fine particles reducing flow due to strainer mesh size that's a good theory but I'm still worried something's in that water jacket somewhere. I will look into getting a bigger mesh size but currently I'm $60 into 1/2 jabs strainers because I bought two im going to tap the pump and run dual cooling with dual strainers and a bypass valve. I'm really happy with my boat exactly how it is and the last thing I want to see is a blown motor at this point of the year.

amk
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1/2 inch strainer on a 3/8 inch line any problems?

Post by amk »

whats the best way to join the ends together if I rolled my own.

CedarRiverScooter
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1/2 inch strainer on a 3/8 inch line any problems?

Post by CedarRiverScooter »

Stitch it w/ aluminum or stainless weld wire?

bellman
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1/2 inch strainer on a 3/8 inch line any problems?

Post by bellman »

amk wrote:My boat has a visible pisser and when it over heats there's still flow it just has steam mixed in. When I first got my boat back and running after I re did it I ran it on the river when it was really low. I was still getting used to the stick and I pretty much ran it over a sandy rock bar more than once before I had the strainer. I had to float back to the ramp because I lost cooling flow totally. I used an air compressor to blow the lines but it just seems to run hoter now. The other day when I had it in the bay it ran fine but I went home put it on the river to flush with fresh water and it got hot and would predetonate fuel every five minutes if I didn't stop and let it cool. The river was high and had lots of small sticks and debris from all the rain here in Texas recently but I didn't see much on the strainer. Could of been fine particles reducing flow due to strainer mesh size that's a good theory but I'm still worried something's in that water jacket somewhere. I will look into getting a bigger mesh size but currently I'm $60 into 1/2 jabs strainers because I bought two im going to tap the pump and run dual cooling with dual strainers and a bypass valve. I'm really happy with my boat exactly how it is and the last thing I want to see is a blown motor at this point of the year.
.

When you say you have flow, but with steam or air mixed in that almost always means your head gasket is leaking. More times than not, you can replace the gasket, but instead of dry, use a fairly thin layer of 3bond 1211 on it (both sides). Yamabond 4, Suzukibond, and Hondabond used to be the same thing, but they've since changed formulas. It's about $16-18/tube, but it'll last you forever and it's good for ANYTHING that ails you. Other products make nice claims, but 1211 is the ONLY one that ALWAYS works. It's what you seal your cases with also. You can also torque the head bolts several ft lbs more than spec to help, although on Yamaha motors I ALWAYS install studs in place of bolts. If you strip a stud you pull it and install another. If you strip a bolt hole, you'll have to install a helicoil or timesert. You can measure and buy studs from Mc Master Carr of just order a meter of 8 x 1.25mm stainless threaded rod and cut to length. They also carry SS nuts and washers to finish the job. I just install the studs with a bit of red loctite and use two nuts to install firm, but not too tight into the cylinder. On the screen thing, you can fold one edge one direction and the other edge opposite and they'll interlock. Place the tube over a small piece of pipe about the right size and seal together with a hammer. FWIW, I did find my 3/8" strainer while I was in the shop. If you want it just PM me your address and you can have it. Give Robert a call at Jetworks and tell him what you need and he'll get you squared away at a reasonable price. Tell him Charles told you to call and that I said for you to demand a good deal :wink:. You can get him at 949-548-5259. He's the very last of the good guys.

Charles

amk
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1/2 inch strainer on a 3/8 inch line any problems?

Post by amk »

Well that's the second time I've heard my head gasket might be leaking. Possibly could be from when I first over heated it on loss of all cooling. The steam I mentioned in the water was only after I shut it off it wasn't constantly running with it but I will pull and replace gasket I have one at the house. Thanks for the strainer offer I will probably stick with mine since I sunk money into them but I really appreciate it that was very generous.