SRX 700 Coolant Leak

Yamahahoo

Yamahahoo

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Joined
Oct 8, 2010
Messages
484
Age
31
Location
Readfield, Maine
Sled loses coolant every time I ride it. Performance doesn't seem to be effected it pulls the rpm it should with stock clutching, over revs actually. Have never seen it leak externally, even when put on a stand and then observing the snow beneath it. The cap of the container holding the coolant however doesn't lock in all the way, I have a new container on order. When I open the cap after riding there should be a great pressure release, however there isn't. Is the system simply not under enough pressure and so the coolant is evaporating at a temperature lower than it normally would? If the new container does fix the loss of coolant, where should I go from there? What else would cause the lack of pressure, if any, that I observe when removing the cap after a ride? Thanks! ;)!
 

Use a pressure tester, not sure of the correct name for the tool.
You would remove the cap on the bottle, screw on the the attachement for the tool in place of the cap you removed.

Then pump up the pressure. There is a dail on the tool which reads the pressure. Leave the sled sit for a bit, 1/2 hour to an hour, come back and see if the pressure level has dropped. If the pressure has dropped then you know you have a leak somewhere.

I tend to agree with you, if the cap is bad then the coolant might be evaporating.
Or
You might be bruning a small amount.
 
Thanks Sleigher will do! And yes it could also be burning, would that result in certain odor being produced, or would it effect performance in any way? Probably not if it's only a small amount, which it is.
 
Yeah. I dont know if a small amount would be noticed in the exhaust or in performance.

I thought mine was losing a little coolant as well but it seems to have stopped.
I could smell or see in exhaust, I couldnt see a leak either.
 
check your plugs.Maybe some coolant getting by the 0-rings on the cylinders somewhere.Plug would be Grey I think if coolant is leaking inside.
 
hey jason i am afraid that leak may be the front heat ex. at a spot u cant see. need 2 pressure test it inside and wait 2 see if u can see it leaking.
 
Powervalve that has milky residue would be from a coolant leak in the cylinder.
 
Thanks for suggestions, I guess my dad is bringing it to a shop tomorrow. Heat exchanger leak seems very plausible though. Need a gauge to test pressure, good place to start.
 
LaPorte429 said:
Thanks Sleigher will do! And yes it could also be burning, would that result in certain odor being produced, or would it effect performance in any way? Probably not if it's only a small amount, which it is.
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if its drinking it in engine you will see it on the plugs and piston tops, even minor leakage into engine will show signs of green/white fuzz on plugs, cone will be shiny wet color from antifreeze. Usually the piston will get the carbon removed and become silver/shiny. You should also start noticing more smoke and a sweet smell. of course this all depends on how bad but it will show up somewhere, look at plugs first.

ADD: just saw this in your 1st post, if the cap is bad you could be just dumping it out the over flow hose, look real close at the right hand foot well for signs, as you said with no pressure coolant will boil at a much lower temp and cause this from expansion.
 
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was leaking at hose conn. to front heat ex. lucky in a big way it was not ex. itself. mercy. should have looked into getting press. tester
 
got to keep an eye on the hoses as our sleds are starting to put on the years.Had to change my hose from the bottle down to the pump.It almost wore thru at 1 spot because it is rubbing against the motor.Now put new hose on and put protective barriers/shield between the two.Clamps may also loosen in time and corrosion where the hoses connect to as well.
 
bluemonster1 said:
got to keep an eye on the hoses as our sleds are starting to put on the years.Had to change my hose from the bottle down to the pump.It almost wore thru at 1 spot because it is rubbing against the motor.Now put new hose on and put protective barriers/shield between the two.Clamps may also loosen in time and corrosion where the hoses connect to as well.
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yup constant attention required and then some. as long as u can do most if not all of it yourself i feel good about it.
 
well this is so funny but today I find a dripping from my water pump cover just looking thru my pipes and see a drip when idling..now I am pissed off now.Changed all my seals when I rebuilt the motor before last season.Sled will be sitting now as I have had it with it.Winter is a piece of crap as well..so thinking I don't have the need for 2 sleds anymore.One will do.May part out the SRX soon.... :o|
 
bluemonster1 said:
well this is so funny but today I find a dripping from my water pump cover just looking thru my pipes and see a drip when idling..now I am pissed off now.Changed all my seals when I rebuilt the motor before last season.Sled will be sitting now as I have had it with it.Winter is a piece of crap as well..so thinking I don't have the need for 2 sleds anymore.One will do.May part out the SRX soon.... :o|
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every man has his limits lol
 
getting to the end of my rope soon..spent to much on the sled to just part out really..but don't want to spend any more on it now.Can't believe I have a leak NOW!! After it was good all last season yet..gees!!
 
What pressure tester did you use? I'm having the same issue and can't locate a leak. I would buy a pressure tester but not sure what the "cap" size is.
 
Rebmo said:
What pressure tester did you use? I'm having the same issue and can't locate a leak. I would buy a pressure tester but not sure what the "cap" size is.
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You could always measure your cap.........Or take it with you if your buying it from a brick and mortar type store.
 
I'm having a problem with a 2001 sxr700 (3k mi) losing coolant so I've been monitoring this thread. I ordered a Mityvac motorcycle cooling system test KIT Model MV4510 yesterday. I'll report back and let folks know if it works. I did a lot of research to find the right size pressure tester but could not find the Yamah tester P/Ns from my manual. I found this tester for $30 plus about $11 shipping and took a gamble based on the description of "fitting most motorcycles and RVs which have a common size cap (didn't say what size). Hopefully it fits and I can avoid trailering off to the dealer and paying a lot more to get it pressure tested.

Update: I pressure tested static & dynamic with the Mityvac pressure tester and found no leaks. I just happened to switch the carb heater on/off valve while it was running and noticed a slight leak in the on position. After careful inspection I could see that there had been coolant leaking and dropping down below the valve, but it was not easy to see. I had pressure tested in the off position and usually run in the on position. So, I ordered a NOS replacement on/off valve for the carb heater and installed the new valve. Since then no coolan loss. Fixed. Ran several times after the fix and did not lose a drop of coolant.

Check all your connections and even the on/off carb heater valve in both positions and in between for leaks while warm or under pressure. Found one on Ebay for about $15 shipped NOS, cheap fix. Also, the Mityvac RV coolant system pressure tester is a decent lower cost tester to check for system leaks and cylinder/head leaks. I found it impossilbe to get a specification for the coolant cap size and took a chance on this "RV" coolant checker and the size was perfect. The description was something like "fits most RV applications" and that was correct for my SXR 700.

Reb
 
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