rad cap who-doo

[kdennan]

Searched the site last night about boiling over the radiators.
Once again I have to give praise to this awesome site!
I put the Engine Ice in yesterday. I was running Moose brand for the past year. Being skeptical that it would be the complete answer, and I remember reading some where in some mag about some bike needing a higher rated cap, I got to thinking..... Is that what the 220 needs?
Sounds like a cap that fits(any rig with a radiator might fit) is a 1.6
I ran out to check my artic cat sled first thing this morning and it says 16 pounds. It fits, so I am wondering if this is an english/metric thing. Does the 16 translate into 1.6?
It would be awesome if so. I have to ride with 3 other guys tomorrow so I think it is safe to say that I will be plunking along. Since there are no shops close enough that would even have a spare I would love to use this cap until I can get a new one.
Whaddaya think?
Thanks

[m0rie]

I think a KX500 rad cap is a 1.6

[IdahoCharley]

It is based primarly upon atmospheric pressure - hence a 1.1 cap at sea level would retain a pressure of (1.1)(14.7) =16.1 psig prior to releasing and a 1.6 cap would retain a pressure of (1.6)(14.7) = 23.5 psig prior to releasing.

If your running at higher elevations say 10000-10500 feet the atmosheric pressure is roughly 10.5 lbs/in2 then the 1.6 cap is (1.6)(10.5)= 16.8 psig prior to releasing.

Hope this helps.

[kdennan]

Thanks Charley.
One other thing: Obviously Ma Kaw wants us to run coolant in the catch bottle but I never have and have heard not to from many.
It is not a bad thing to put some in so why not?

[IdahoCharley]

I still run the catch bottle on the Sam's bike. It likely does block a little air flow on the back side of the radiator but I haven't seen that as a problem.

I overheated the KDX 200 to the point of steaming once and was glad to have the catch bottle. Radiators just will be more efficient if you can keep them plumb full of fluid. When you blow fluid and don't run a catch bottle then you are running the bike with some air space in the radiator which cuts down slightly on the thermal heat sink available and you lose a little potential heat transfer from the radiators for the engine's heat.

That said many bikes do not have catch bottles. My KTM steams every once in a while when going too slow to cool on a hot day and once the fluid is lost it is easier to get the engine to steam a second time due to the smaller volumn of fluid transfering the engine heat.

[canyncarvr]

WoW..math!!! Cool! It's even cooler (another lame joke) when it's correct!

Replacing the cap is likely a good idea. 'Likely' 'cuz the gaskets on most caps aren't in good shape 'cuz they have been used for too long. You would (again, likely..again...sez me) get more benefit from replacing the cap from the standpoint of new gaskets than you would changing to 1.6kg/newt/fig.

The way it would go: 'I changed from a 1.1 to a 1.6 cap, and all my heating problems went away! The 1.6 is GREAT!'

...no. It's just the new sealing effects of the new cap worked. A new 1.1 would have worked as well.

I'd rather run less pressure than more, given the choice.

Rez bottle: They are most always empty due to jiggling around and sloshing out on a day's ride, but for the short term used to capture overflow from overheat and recapture due to cooling down, you can't beat 'em. It helps to reroute the overflow hose (out of the bottle) to have a higher loop in it.

If you check the level of the rez bottle before each ride you will likely find it's low..or completely out. That's the jiggle/slosh part. If you don't refill it and check the rad level you will likely find the level stays fine. That's the rez bottle doing its job.

Anecdotal: I took my rez bottle off under the mistaken thinking of: 'It's always empty, so why not remove it to improve airflow?' THEN I found my rad level to be in a consistent state of replenishment (the bottle not being able to DO its job).

So...I put it back on. Problem solved.

Oh...if you choose to put coolant in the bottle regularly, watch the cap gasket. It tends to fall out when you're not looking. Another reason to leave it alone!

The 220 is generally reported to have overheating problems. Address them as best you can. I wouldn't be of the opinion that more pressure is part of that address.

My 200 overheated on a regular basis...until I took off my out-of-round POS (not Point Of Sale) US-Chromed cylinder. Don't have that problem now. Funny how preheating the intake charge via blow-by can cause all sorts of problems.......

I digress..........ed.............

[kawagumby]

I just purchased an extra head for my 220 and am waiting for it to be shipped. I'm going to have Ron do his stuff to it as I'm very interested in finding out if it will reduce the coolant loss issues the 220's have at low speeds (as compared to the 200's). I'll let you guys know what I find out.

[kdennan]

Yeah, Thanks CC.
I am ordering up a new 1.1 and re-installing my catch bottle.
Definitely low today when I checked it and I have not seen that before.
The bottle wins!