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My cure for the poor radiator flow issue.

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Well,,,,I've been giving this way too much thought and here's what I've come up with.

I will have this mod done myself but only after I take some stock temp measurements so I can have data to compare. I'm waiting on my temp indicators to arrive via the mail.

Anyways.

I have a welding fabrication shop ready to do this mod. Most rad shops around here work in brass rads and are not up to the task of fabricating and welding aluminum.

I will have them weld a 3/4" spout on the bottom of the left rad in place of the existing 1/2" one.

At the y-piece entering the impeller housing they will cut off the the 1/2" tube and replace it with a 3/4" tube.

Once this is done and installed I will have to restrict the 3/4" spout, exiting the right rad , to 1/2" .

The end result will equate to ------

3/4" inlet into the top of the right rad.

3/4" outlet from the bottom of the left rad.

1/2" joining both top and bottom rads.

The flow will be properly balanced between both rads and will result in a cooler running engine.

Some companies offer this service for $250+ USD. :cry: The shop I'm going to will charge me less than $80 USD for the same work. Follow your gut but don't get riped off.

After these temps are taken I may take it one more step further.

I may have all the 1/2" spouts increased to 3/4". Then series the rads as is done on the KDX. The larger spouts will not hinder the flow even though the flow will have to travel up one of the rads.

Hopefully my temp indicators will arrive soon. If not,,,, I may have to run out and purchase a digital thermogun. ( maybe the guys at work will let me borrow theirs....heehe )

Side note.

Purchasing larger rads will help with cooling but will not resolve the flow issue. If the impulse to buy is too much to resist,,save some money and just buy the right rad. It does most of the work...and it's cheaper to boot.

Cheers.

Hope someone can make use of this info.

Joe

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You are going about it backwards, Add a 3/4 inch pipe into your upper left radiator and install a y pipe into the port exiting the head and run the additional hose to the left upper hose connector The problem is flow getting to the left radiator not exiting it, You will only magnify the problem by causing a larger exit. Take your time ponder on this.

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Art5,,,,,you're kill'n me buddy. :cry:

Additional pondering not required.

Increasing the inlet to the left rad will help. But you'd be better off doing what flarmz did. Saves even more money.

What I've describe in my first senerio mimics what most other bike have. That being the large inlet and outlet at opposite ends and smaller balancing lines joining the tubs at their tops and bottoms.

Increasing the outlet from the left rad and decreasing the outlet form the right rad is what will make this work.

My KDX runs the rads in series and all lines are 3/4".

Buc

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Yes it would be easier and less expensive, unfortunatly your still using a much smaller inlet tube verses the right radiators 3/4 in inlet

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Ture,,,,but in your case you will still be using the same 1/2" outlet on the left rad. Won't matter how large the inlet is if the outlet is restricted .

Point in case......a garden hose. Opening the valve at the house all the way won't help any if the nozzle in your hand is only open half way.

Of course we are dealing with a closed loop circuit here with additional pressures created by heating,,,flow vs pressure and the fact that they are inversely propotional to each other. And not to mention bernoli's. :cry:

And there is still that large oulet on the right.

Better,,,yes.

Balanced,,,,,no sir!

Buc

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When you checking your return flow, pay close attention to the bottom tube on the right radiator where it returns into the pump notice the restriction there, I'm not guessing Kawasaki did not block off a 1/3 of the y pipe by accident, But it doesn't really matter I'm not going to get on here and match wits with you I'm probably in way over my head.

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Correct.... I have removed the restriction in my system. Thanks for pointing that out. :thumbsup:I forgot to mention that. It's key in balancing.

I wonder if flarmz has removed his.?

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Hey Joe well im just wondering what air temps and hum are you guys in to have your bikes overheating i havent experienced a summer here in australia on my bike yet so im a bit worried we get in the mid 30 and high 30s in a hot summer with hummidty around the 90s thats celsius temp to

Thanks

Brad

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Hey Joe well im just wondering what air temps and hum are you guys in to have your bikes overheating i havent experienced a summer here in australia on my bike yet so im a bit worried we get in the mid 30 and high 30s in a hot summer with hummidty around the 90s thats celsius temp to

Thanks

Brad

Brad....those are the same conditions we experience here in Ontario,Canada.

I have not overheated to say but instead have lost coolant. All bikes will.

I'm a bit of a tinkerer and love the challange of making something better.

I have since installed an overflow bottle and this on it's own will resolve most of my issues.

I will have the rad mods performed, as mentioned, more so as an experiment with the benifit of a cooler running motor.

I ride exclusively woods and only hit the rev limiter during brain farts.

To date I have not experience any valve problems. I did just finish taking the top end apart and everything was perfect.

Winter nears so I'd better get off this computer and get riding. :cry:

Cheers from Canada

Joe

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I went for a ride yesterday with the intent of taking temp readings.

To my suprise,,,,I found the inlet and outlet temps of the right rad were the same. 176'F.

The left rad was 158 inlet and 140'F outlet.

Obvisiously there is a flow issue between the two sides.

I'm left wondering if cleaning the y-piece at the inlet to the water pump is causing too much flow throuh the right rad preventing the coolant from staying in the rad long enough to cool. ???????

I will order and new y-piece and take more temp readings to compare.

Joe

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Hate to say I told you so, but I did, when you removed the extended pipe you just sped up the return to the engine via the right radiator, and with the temps you took whats the problem, My car gets hooter than that.

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You should be worried about the head more than the temp of the coolant. Although, the coolant temps are important if you are trying to measure flow evenness the head is what matters the most.

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Anyone know how hot hooter is, Damn I need to try that correction thing.

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When you checking your return flow, pay close attention to the bottom tube on the right radiator where it returns into the pump notice the restriction there, I'm not guessing Kawasaki did not block off a 1/3 of the y pipe by accident,

Art, So you are saying that it is partially blocked off for a reason, right? And some people are grinding it all out thinking they are improving flow when that is not the case?

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Only a blind engineer would have overlooked it, They left it restricted for a reason, why they didn't just install a smaller fitting in the bottom of right radiator I don't know, havn't really checked into it all that much, but would assume they just welded the left radiator inlet pipe deeper into the main right to slow down the flow, havn't had any overheating issues yet, but if this is what they have done, it would make more sense to grind away the pipe protruding through closest to the water pump, that way you would still have the restriction from the top while clearing out the flow from the left coming in,I'm still waiting for my new 3/4 inlet pipes to come in, Without the new main pipe coming in you still won't achieve your goal,more of your coolant will run through the right radiator than can spill off into your left from the bleed off hose attached between the two, Considering the left and rights middle of the tank attachment, there is no amount of force in this system to keep a constant circulatory movement of coolant evenly through both, the closest option is to remove crossover hose block off right side and install y pipe with seperate inlet to left tank, as pictured before, Oreillys auto parts sells a y pipe connection with a stepped down section from 3/4 to 5/8 hose fitting that would actually give a more direct flow into the pipe going to the left,

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Hate to say I told you so, but I did, when you removed the extended pipe you just sped up the return to the engine via the right radiator, and with the temps you took whats the problem, My car gets hooter than that.

Indeed you where correct,,,,and through experimentation we learn and determine fact from fiction.

The problem is that I now have a rad that does little,,,,and another that does nothing.

I puked more coolant into the overflow bottle yesterday than any other day.

I've order a new y-piece and once installed I'll take more readings.

Joe

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That is how we learn, I wish we just knew, unfortunatly thats not the way it works, If we sit by and do nothing we learn nothing. I applaud your efforts.

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