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cooling problem
Posted: March 3rd, 2008, 10:57 am
by ISBB
So i have had it about up to here ( isbb holds hand above eyeballs ) with the 500.. For the life of me i cant seem to get it right and just keep throwing money at it and shit just keeps breaking no matter what.
Needless to say this weekend the bike was running real HOT.. HOT enough to send a shower of hot coolant all over me. I thought at first my retarded ass left a hoseclamp loose.. well the last time i did that it just spooged everywhere adn didnt blow off... this one literally went boom.. So now i need to find out WHY it did this... Ohh ya best part.. in the midst of this happening... i managed to loose some compression too.. so the cylinder gets to come off again... So if anyone has any bright ideas it would be greatly appreciated.
Posted: March 3rd, 2008, 11:29 am
by britincali
I would pull the rads and have them proffesionally rodded out.
Posted: March 3rd, 2008, 12:18 pm
by ISBB
just dont know why or how this would happen... didnt have any issues last time we rode... then i take it apart put it together then boom.. ugg
Posted: March 3rd, 2008, 12:21 pm
by Slow old Fart
Are you running stock compression? the bikes are usually pretty good about not overheating until you cut the head and then they like to overheat in situations where you are torquing the motor with out moving much air through the fins like hill torqing other than that it must be something not right with the coolant circulation.
Posted: March 3rd, 2008, 12:23 pm
by Slow old Fart
ISBB wrote:just dont know why or how this would happen... didnt have any issues last time we rode... then i take it apart put it together then boom.. ugg
You may of had a leaky head gasket?
Posted: March 3rd, 2008, 12:24 pm
by ISBB
well i wouldnt say it was a problem with the airflow was hammering between 4th and 5th trying to keep up with these damn buggies in the sand.. I know it was a warm day in the 80's but i wouldnt imagine that to be the culpret... ohh well.. ill take it apart and flow everything and make sure everything is still flowing properly and then check out the waterpump.. IM wondering if something happend in the pump that cause the circulation to stop.. then it just got hot enough that the water just boiled in the head and created enough pressure to make it go boom.
Posted: March 3rd, 2008, 12:24 pm
by Slow old Fart
ISBB wrote:just dont know why or how this would happen... didnt have any issues last time we rode... then i take it apart put it together then boom.. ugg
You may of had a leaky head gasket? Or i have actually sen rebuilds where people will get something in the coolant systen impellar and jam it up?
Posted: March 3rd, 2008, 12:25 pm
by ISBB
no seepage around the head and i didnt have the head gasket off when i took the bike apart.. only pulled the motor and set it on the shelf.. so i could paint the frame..
Posted: March 3rd, 2008, 12:32 pm
by britincali
I had overheating issues with my '87, I ended up putting a catch can on but it still got hot as hell. I put that same motor in my 2000 frame and it has never overheated since (blocked rads on the 87 frame)
Bobs steelie cooked itself bad at glamis for no apparent reason and since hes slapped the motor in the AF its been tits.
Pull the rads.
Posted: March 3rd, 2008, 12:34 pm
by ISBB
will do.. Ill get to it after the wife leaves for the UK then i will have 3 weeks of working on it without her bitching at me " YOUR SPENDING TOO MUCH TIME WITH YOUR BIKE AND NOT MEEEEE "
Posted: March 3rd, 2008, 12:39 pm
by britincali
You may have disturbed something in the cooling system that blocked a couple of tubes and pushed it over the edge, Ive tried caustic soda and rad cleaner before to no avail. I would call a few rad shops and see how much they charge to remove the end caps and rod them out properly.
Posted: March 3rd, 2008, 2:33 pm
by AlisoBob
britincali wrote:
Bobs steelie cooked itself bad at glamis for no apparent reason and since hes slapped the motor in the AF its been tits.
100% true, and very odd. Boiled over on the flats by the General Store...
WTF!
When I hacked off the spouts for the A/F conversion, I could see inside pretty well.... clean as a whistle.
More power = more heat. Getting your engine back up to spec may have exposed a cooling system that was barely keeping up before the rebuild.....

Posted: March 3rd, 2008, 2:33 pm
by dannygraves
tuning can be a huge factor, a slightly lean needle can create huge cooling issues when under load at partial throttle. check the rads and make sure the plastic gear for the waterpump isn't spinning freely.
with it running cold and the cap off, you should see the water flow down the tubes, if not, you have a blockage and waterpump prob. also try a new cap, its only a fw bucks and could save your ass.
I've been successful at getting the rad warm leaving it in the sun then taking the garden hose and running water through the rad and seeing how well it flows thoughand checking the sides to see if they are getting cold from the water. I've seen some where water flows through, but only through a handfull of rows, so the whole thing doesn't get cool.
Posted: March 3rd, 2008, 2:47 pm
by ISBB
only tuning changes were pilot went fatter and main went leaner.. didnt change the needle.. However i did change the pipe and the tune could have been off but i was already retardedly fat to start with.. i dunno.. finicky things i say...
Ill pull everything apart later this week and do some investigatin..
Posted: March 3rd, 2008, 2:50 pm
by dannygraves
I have a pwk that is dialed in for my bike, if you want to borrow it to rule out carb issues, let me know. its not on my bike, but it is going on my gen-4 build.
Posted: March 3rd, 2008, 2:51 pm
by dannygraves
did you have to remove any ignition parts? I only ask because if you removed the stator plate, the timing might be off which could definitly cause overheating.
Posted: March 3rd, 2008, 3:13 pm
by ISBB
ill take that mikuni you just finished dialing in though
Lemme get this coolin system sorted out and if everything appears normal then ill get down to the carb.. then if thats normal then i guess MFDB will say i told ya so and prolly do crank seals.
Posted: March 3rd, 2008, 3:14 pm
by ISBB
only ignition parts i took off is what was mounted to the frame.. coil and cdi.. nothing game off the motor internally other than carb and reeds to take a looksey inside.
Posted: March 3rd, 2008, 7:07 pm
by bigjay
i feel your pain on the cooling issue, thats why my top end just went to shat, my right radiator is blocked all the way, im going to cut into it tonight and see wtf is up in there, should be interesting pics as everyone ive talked to says theyve never heard of a radiator bieng 100% blocked.
Posted: March 3rd, 2008, 10:17 pm
by britincali
bigjay wrote: everyone ive talked to says theyve never heard of a radiator bieng 100% blocked.
Ive worked on a lot of old stuff and Ive seen it a lot.
Posted: March 3rd, 2008, 10:31 pm
by bigjay
britincali wrote:bigjay wrote:
Ive worked on a lot of old stuff and Ive seen it a lot.
i didnt open them up tonight, got wrapped up doing stuff with rhe kids, tommarow will tell, the more i think about it the more i wonder how inthe hell all of the cores can get clogged up at once.
Posted: March 3rd, 2008, 10:35 pm
by britincali
bigjay wrote:how inthe hell all of the cores can get clogged up at once.
If something moves or lets got inside the motor (big blob of gunge) it'll happen, it dont take much to dislodge something thats been building for years.
Posted: March 3rd, 2008, 10:44 pm
by Ported&Polished
I've had radiators so clogged, when I cut them open, there wasn't one tiny amount of space in them for water, let alone any flow. But so you know, motorcycleradiators.com can help.
Posted: March 3rd, 2008, 11:14 pm
by dannygraves
its called magnesium guys, it corrodes from using water and covers everything in nasty white powder that sticks to the raditor cores until they plug up. My old 125 left rad was totally and completely plugged.
Posted: March 4th, 2008, 10:59 am
by ISBB
been using engine ice.. not straight water.. ohh well.. ill figure it out..