Ideas for Overheating 500

ISBB · Post by **ISBB** » March 17th, 2009, 2:04 pm

new waterpump shaft, bearing, both seals and new rad cap (black one) Rad's flow free. Still manage to kill a WP water seal and blow steam/water out the weep hole. Has done it twice. Im going to soak the jug and head in clr for 30-45 min and flush it out hopefully getting rid of any contaminants in there. Also throwing around the idea of "Rodding" out the rads at a local rad shop.. Dont know if i want to do that since i know they flow free.

Jetting on the 41pwk is stupid fat so i know its not a lean condition. 55 pilot and 180ish main i believe. DGN on 3rd clip. Super fat pilot that bogs on the bottom as soon as it gets past that it rips like no other. No pinging or other odd noises coming from the motor.

I can cruise it around all day on a mild ride which is what i was doing the first day back in the sand.. the last run of the day was a "fast guys" ride where i was hammering the piss out of it. Thats when the seal let go. I thought i just had a crap shaft and thats what killed it. It did it the following trip with all the new stuff and i wasnt even hammering on it. Just a mellow cruise. Thought i heard a hissing noise so i stopped and noticed it was barfing water again. Let it cool filled'er up and headed back to camp. Lookin fer some other ideas as to why it keeps doin this crap.

Post by **AlisoBob** » March 17th, 2009, 2:13 pm

Last ride on my steelie at Glamis ( before the A/F conversion) I had MAJOR overheating issues.... Even on flat ground over by the General Store

I thought the water pump stopped turning, the jetting was too lean, my rad's were plugged.... couldnt find anything wrong.

Parked it for the rest of the day....

When I did the conversion,. I pulled down the water pump to check the gear.... Perfect

I checked the carb.... nothing blocking any passages

The guy I sold the rads to never had an issue with them....

The motor now runs VERY cool with the CRF rads... much cooler than with the 500 rads.

I never found what the issuew was.... never did it before, or since.

I know this sheds no light on the question, but I thought I would pass it along.

rickyrcf · Post by **rickyrcf** » March 17th, 2009, 2:19 pm

Most of my riding includes or is mostly gnarly. Overheating in the snow below freezing temps is (was) common. simple solution was a KTM fan.
About $100. END OF PROBLEM PERIOD

dannygraves · Post by **dannygraves** » March 17th, 2009, 2:57 pm

Nick, how are you putting your pipe on? like how is it sealing? Any cracks in the pipe? is the rad w/o cap flowing ok? have you run though it wait a garden hose and feel the whole thing get cold?
on the pipe, I don't even bother with one of those crappy stock gaskets, I use a big sloppy mess of ultra copper RTV and the bitch stays sealed. I remember a big nasty mess on your jug from the pipe leaking.
Don't forget when you are on the pipe, the contents of the pipe get blown back in and if there is a crack or other opening it can get lean as all fuk!
I know that motor is fucking solid! don't pull the head or jug, you won't find anythign wrong there.

ISBB · Post by **ISBB** » March 17th, 2009, 2:57 pm

this only started happening after i disassembled and reassembeled rolling chassis to paint frame.. first time it built up enough pressure to blow a line off the head.

dannygraves · Post by **dannygraves** » March 17th, 2009, 3:00 pm

CHECK THE PIPE SEAL!

ISBB · Post by **ISBB** » March 17th, 2009, 3:06 pm

i just cant forsee a leaky exhaust flange cause that much trouble.. Ill slap a new one one. Still looked good last time i had it off.. especially since it went an entire season with the stock flange and gasket and not one problem..

fastkart · Post by **fastkart** » March 17th, 2009, 3:18 pm

dannygraves wrote:CHECK THE PIPE SEAL!

ISBB wrote: just cant forsee a leaky exhaust flange cause that much trouble.. Ill slap a new one one. Still looked good last time i had it off.. especially since it went an entire season with the stock flange and gasket and not one problem..

I've tried just the stock exhaust seals, tried the seals and ultra copper rtv and ultra black rtv (separately)... nothing keeps mine sealed. The RTV is always burnt off after a night of racing (1hr at most of engine run time).

I have an inline temp gauge (Trailtech Vapor) and have never seen my water temp above 180*.

ISBB · Post by **ISBB** » March 17th, 2009, 3:33 pm

i might slap in an old analog style gauge heh.. just for a quick glimpse here and there.

iggys-amsoil · Post by **iggys-amsoil** » March 17th, 2009, 3:38 pm

The seals in backwards, and over filling the rads.

ISBB · Post by **ISBB** » March 17th, 2009, 3:49 pm

put the seals in the same way they came out and only filled the rads to about the top of the fins inside.

dannygraves · Post by **dannygraves** » March 18th, 2009, 8:07 am

I rebuilt this motor and did everything the exact same way I have done my 3 500 motors. its not the motor. sounds like the rads to me...

dannygraves · Post by **dannygraves** » March 18th, 2009, 8:09 am

if you didn't say you already did that rad cap, I'd guess that because the rad cap shouldn't allow enough pressure to build up to blow out the waterpump seal.

hoofarted · Post by **hoofarted** » March 18th, 2009, 9:59 am

AlisoBob wrote:my steelie at Glamis = MAJOR overheating issues....

The motor now runs VERY cool with the CRF rads... much cooler than with the 500 rads.

So there you go. AF it and problem solved!

dannygraves · Post by **dannygraves** » March 18th, 2009, 10:05 am

Hey Nick, I have some '89 rads that are clean as all fuk, they should bolt on. come over and pick them up and try them out. See if the same shit happens again.

ISBB · Post by **ISBB** » March 18th, 2009, 12:53 pm

will do danny. I need to get the suspension rebuild.. Im going to clean everything up while the bike is apart and i believe pickerings only wants like 30 bucks to rod out the rads so if that doesnt work ill come grab the 89's

Im just hoping its the pipe seal since it only seems to happen when im really on it. I havent had a chance to look at the flange. I always just passed off the dirty mess to the extra fat jetting and slight spoogage issues.

100hp honda · Post by **100hp honda** » March 19th, 2009, 1:19 pm

ill tell you my experience with radiators from previous vehicles. my old ford pickup has a huge 4 row radiator, back in the day ford way over built everything on the truck......transmission, t-case, radiator, clutch and the rest of the truck was overkill for what it really needed. the new vehicles however seem to be using smaller, lighter, more compact componets. im sure the cr500 is built on somewhat the same principle to save cost maybe, they dont have 5x the cooling capacity that it needs. so when you get a small blockage, you have big problems. i had a vehicle once that kept running hot, to the naked eye the water seemed to flow normal, but once the rad was flow tested, it showed alittle blockage inside, which was all it took to make it overheat. if theres even the slightest blockage in your rads then your going to have cooling problems. water may flow through, but is it 100% flow ?

dannygraves · Post by **dannygraves** » March 19th, 2009, 1:32 pm

my own little rad test is to leave the rads sitting in the sun, so they are a little warm, then I use a garden hose with the water nice and cold and force water through the rads, where ever the water flows, it should cool rapidly. So I keep my hand over the width on the rad and feel if every tube cools down. sometimes the middle rows are clear, so water seems to flow alright until you discover the side tubes are all plugged up.

100hp honda · Post by **100hp honda** » March 19th, 2009, 2:17 pm

why your seal is blowing out is a mystery to me, ive never seen that happen. if everything is working good, personally i would suspect a partial blockage in the rads, especially if theyre old and somebody previously used straight water which can cause corrosion. you could have a shop flow test them, or do dannys trick, or try a different set of radiators. another thing i was going to say, i use rtv silicon on my head gaskets, but im real careful to not let it squeeze into the water passages and block them, if you dont use rtv then this wouldnt apply to you but just thought i would throw it out there

dannygraves · Post by **dannygraves** » March 19th, 2009, 2:34 pm

yeah, the waterpump seal blowing out is just crazy to me. What kind of radiator cap are you running, nick?
I would normally suspect a faulty cap after seeing a waterpump seal blow out like that. it takes a butt load of pressure to blow out that seal and a buttload of pressure to blow off the upper rad hose like it did before. the rad cap should be blowing it out the overflow before that happens. where is your overflow hose going? did it get pinched between the frame and rad? if the overflow hose is blocked, then I would expect exactly what you are experiencing. when filled to the top, they always puke a little out the first time you heat things up, and if it can't escape, it will try to get out where ever it can. In this case the waterpump seal.

ISBB · Post by **ISBB** » March 19th, 2009, 7:52 pm

danny brand new black cap.. ill double check everything mentioned as well as gettin the rads down to get flow tested/rodded out whatever ya wanna call it.

ISBB · Post by **ISBB** » March 24th, 2009, 1:55 pm

Looked last night.. Exhaust flange gasket was missing pieces go figgure. I also ran the overflow hose between the rad and the frame thinking hey lets keep it out of the way.. Prolly not a good idea. So im goign to replace the flange and use copper RTV with it. There were no cracks in the pipe but a couple dings in the flange that mounts to the jug but they were around the edges and not inside around the sealing portion. I also will have the rad's flowed and rodd'd out if necessary.. HOPEFULLY doing all this will cure the beast

dannygraves · Post by **dannygraves** » March 24th, 2009, 4:18 pm

ISBB · Post by **ISBB** » August 7th, 2009, 9:32 pm

dropped to the 52 pilot.. i actually have a carb that does something when i adjust the air screw woot!! anything less than 1turn it she wants to die.. sweet spot seems to be about 1.5 - 2 turns out and it idles just tits. Not to mention no more revving and dumping the clutch from it being so rich.

Im quite surprised at how well it started for me. Sat ever since my last trip with gas in the bowl ugg.. i hosed it out with carb cleaner while i changed the pilot. A few primer kicks and bam lit right off and damn near idled perfect had to adjust the idle screw bout a .25 turn to get it to idle then i farted with the air screw a bit and got the sweet spot

However this thing seems to be getting hot quick. Im going to run to vatozone tomorrow to see if i can get an analog gauge to throw in there for testing purposes.. Hopefully im just being paranoid lol. Guess ill find out tomorrow night

NightBiker07 · Post by **NightBiker07** » August 9th, 2009, 9:19 pm

you sure everything is sealed up properly? ive seen gaskets start to leak as a motor comes up to temp, and would cause a lean condition, or not let it run at all. check the plug if it overheats again to get an idea of what the mixture is like.

is the timing set correctly? if its too far advanced, it will run hot. assuming you can adjust it? some bikes it is, some it isnt. havent ever had my fingers in a 500.

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Ideas for Overheating 500

Ideas for Overheating 500