Well as some of you may remember I recently bought and 85 Magna only to have it spew coolant all over my drive way as I arrived home :D
I just thought I would record the steps as I go through them to try and eliminate the issue.
I decided first to do an oil change just to inspect the oil and make sure there is no coolant leak into the cylinders. Good luck so far the oil was clean of debreis and did not see any sign of coolant :) I replaced the oil with Honda semi synthetic blend 10W40. (guy at shop said 100% synthetic sometimes makes the clutch slip in old hondas ???)
I also double checked the radiator cap and overflow cap just to make sure they are on and went for a ride. The bike seems fine in motion which leads me to believe it is the fan or thermostat. When I stop I gain about a bar every 45 seconds and once I get them they take about 5 minutes in motion to loose a bar.
The next thing I am going to do is replace the coolent with Honda 50 50. I am going to do what I can to flush the system and look for any obvious clogs or problems with hoses.
Wish me luck
You might want to try a product called engine ice it cost a little more but it is enviromentally friendly and claims to lower the operating temperature by 50 degrees, just make sure that you drain all of your other fluid out because it does not mix with antifreeze. I have it in my bike and it does seem to run cooler. I found it at a honda dealership and the mechanic recommended it.
Quote from: Jerry G TurnerYou might want to try a product called engine ice it cost a little more but it is enviromentally friendly and claims to lower the operating temperature by 50 degrees, just make sure that you drain all of your other fluid out because it does not mix with antifreeze. I have it in my bike and it does seem to run cooler. I found it at a honda dealership and the mechanic recommended it.
You might also try Redline Water Wetter, Pep Boys has it.
Put a sample of the coolant in a "Clean" jar, then take it to a shop that performs smog test. Have them test the sample for hydrocarbons with their smog tester; any hydrocarbons in the coolant indicates a blown head gaskit.
Thanks guys. I flushed the coolant and it seemed to only take 2 1/2 quarts The manual says it will take 3.2 so I am confused.
I drained everything the radiator drain plug on the frame, the water pump drain plug and both cylinder drain plugs so I should have got everything. Maybe I just need to run it around town and check the reserve tank.
Some random thoughts on overheating. Clogged radiator not allowing good flow. You can have it rodded out at most any radiator shop. T-stat not opening fully, replace or test it in a pot of water on the stove with a temp probe, aka the wife's meat thermometer. Cooling fan not coming on. Check the fuse, hidden in the neck area. Pull the fanstat plug and short the 2 pins in the connector, the fan should run. If it does not replace the fanstat with an aftermarket one. Do a spark plug reading at idle to see if you are running lean as it seems that is where you are running hot. A lean mixture generates a lot of heat. You can run it without a tstat just for testing purposes to see if gets cooler at idle. You can also do a cooling system flush with CLR in the hopes that it will remove the mineral buildup in your rad and other parts. It will almost certainly ruin the fanstat and tstat so plan on replacing those afterwards. It will of course do little good if the vanes in the rad are too clogged to flow water.
One more thing, put the front tire on a couple 2X6's and carefully set it on the sidestand. On the t'stat housing is a nipple. Open this and bleed the air bubble from your system. The temp sensor is located there and will give false readings if it measuring hot air.
While we're on the subject, one thing you should not do is install a fan override switch to help with a chronic overheating problem. This is a classic "band-aid" fix. Much better to find the problem and fix it, instead of trying to essentially cover it up.
Well good news I got at the fan and when I connect the circut the fan comes on. So the problem is likely the termo-switch or the thermostat.
I would like to take it for a ride with the fan on for 20 minutes just to see if the bike stays cool to verify overheating is from the fan not activating. Is it harmful to leave the circut completed manually with a paper clip for that long?
Quote from: fujiWell good news I got at the fan and when I connect the circut the fan comes on. So the problem is likely the termo-switch or the thermostat.
I would like to take it for a ride with the fan on for 20 minutes just to see if the bike stays cool to verify overheating is from the fan not activating. Is it harmful to leave the circut completed manually with a paper clip for that long?
Go ahead. It won't hurt anything. You can gey a new fanstat at nearly any of the car parts stores like Auto Zone. I'm running the TFS500 in my 83 V65M.
Try these -
COOLING FAN SWITCH 1984 HONDA CIVIC
1986-1991 Acura Integra
WELLS SW504
AC_PARTS 35934
BECK_ARNLEY 201-0817
GP Sorensen 405-001
ECHLIN FS130
*Borg Warner TFS500
RIG-51735
Well guys I am at a loss. I replaced the fan stat and the thermostat and the bike is still overheating before I can get a mile away from home. The fan is working and the bike seems to run OK when I stick it on with a paper clip.
The fan is just not engaging when the engine gets hot. I don't know what else to do if I take it to the machanic it is going to be more expense then just getting a new bike probably. I am affraid I made a $3000 mistake on this bike :cry:
Have you had the radiator checked? It might be plugged. when you pulled out the fan stat did fluid come out? If you get a bunch of gunk packed around the fan stat it wont have a true temp reading and could show lower temp so no fan operation.
Thanks, I am just really discouraged at this point. Sorry if I sound down.
When I replaced the fanstat I drained the coolant from the frame drain by the kickstand so no coolant came out cause the radiator was drained. I didn't notice any debries but I wasn't really looking for any.
I talked with the guys at the local honda shop and they said a clogged radiator on a motorcycle is a very rare thing. Has anyone else experienced a clogged radiator? I can't get a new radiator for this model but I know a site on the internet were you can have it rebuilt.
Maybe I should take it to the honda shop and ask them to just diagnose the problem for me with some leak tests etc...
Last night I saw some white smoke a couple times I hope that wasn't the head gaskets.
You have isolated it down to 2 ideas. It seemed like it was a power issue until your last reply.
1. A radiator shop will probably be less expensive than the Honda dealer for checking out your radiator (they probably send radiators out for repair anyways).
2. If it is power to the fan. Trace the power and isolate where it stops before it makes its way to the fan motor. Is there a FAN RELAY switch?
If it is just the Fan Stat on the radiator that switches the fan on/off and you have power to this point than you could set the stat switch in boiling water and see what temp it makes a connection.
If the fan does not work trick it to function as it should and eliminate that possibility. If you can't, than remedy that before you move on.
I don't know this bike but this should not be difficult to remedy. Process of elimination.
If it were a head gasket your water will be down and the cylinder/spark plug will look like New. Take your plugs out and see if any are clean as a whistle (if enough water has gone through). But you mentioned your fan was not coming on....I would trick the fan into into working (heat up fan switch to make fan come on) and eliminate after I check my plugs.
Need to fill in your profile.....Where do you live?
The other thing to check is the oil. Water and oil make a very nice chocolate syrup looking combo when it gets bad. I know that's what I found in mine when it blew the head gasket. The spark plug was also very pretty a clean in the cylinder which had the bad gasket.
It's a bit of work but redo-ing the head gaskets but it's not that bad.
Thanks you guys always cheer me up. I should wait a little longer to clear my head before I post after a bug disappointment like that.
I am going to check some things out tonight. I've changed the oil and everything looked good there.
Now that I think about it there was quite a bit of coolant on the engine last night from changing the o-rings on the coolant tubes to the heads. I bet the smoke was just the engine getting hot enough to cook that coolant that dripped on the engine.
I am not giving up yet, more later.
Also maybe your gauge is reading incorrectly, when you say it overheats is it boiling water out into the over flow? Also if the spring on the rad. cap is weak it will release water into overflow bottle at a much lower temp. It just measures pressure and the higher the temp the higher the pressure. You might want to splurge and get a infrared thermometer, then you can real time measure what temp. your engine is getting to. Not sure if you may have a air pocket but think there is a bleeder screw on the thermostat housing. You can also feel your radiator for cool spots while it is warming up to see if there are any plugs. Also did you put distilled water in your radiator when you changed the fluid? Tap water has minerals that will cook out of it at high temp. I'll find you a link for the thermometer so you know what I'm talking about. http://www.amazon.com/Extech-42500-Farenheit-Infrared-Thermometer/dp/B0000WU19S
Thank you for the extra advice nick. I've decided to start checking each component individually starting with the radiator. I found a site online that rebuilds and removes any clogs in the radiator. I am not certain the radiator is a problem I just thought it would not hurt to do that. While its disassembled I'll check all the hoses for clogs.
Does anyone know how to test the water pump? The person I bought it from had just replaced it but I just want to double check it is working. I know they replaced it because they gave me the old one when I bought the bike.
So far I replaced and installed brand new fan switch that goes on the radiator along with the thermostat but the fan is still not coming on when the coolant starts boiling (after about 5-10 minutes on the road). I think there is a coolant flow problem either a clog or the water pump is not working. Even when I short the fan for constant run it still overheats. During all these trials I used fresh honda coolant and oil so there should not be any issues that would come from bad coolant or oil. Even if the coolant is leaking into the oil I would expect to get a few miles on the bike before symptoms of that showed up, no?
Can anyone advise the best way to test the radiator cap for pressure. I can't seem to find a new one online for purchase so I want to see if this one is working alright.
Quote from: nicklec on August 30, 2007, 12:50:01 PM
Also maybe your gauge is reading incorrectly, when you say it overheats is it boiling water out into the over flow? Also if the spring on the rad. cap is weak it will release water into overflow bottle at a much lower temp. It just measures pressure and the higher the temp the higher the pressure.
Yeah the bike is physically overheating, it may be the cap. I heard a bad cap pressure can lower the boiling point of the coolant but there are other signs that point to something else like the fan not coming on. I've tested the fan actuation by shorting it with a paper clip and the fan does work. But even with the fan on constant on it still overheats. I am starting to think it is a flow problem that the coolant is just not flowing through the system.
Without re-reading the entire post.
If the fan is not coming on you do need to trace why.
Many reasons
Not pertaining to this model.
In general.
Where does it get power and work from there to where the power is no more.
Bad Fan relay, if there is one.
Fan switch, should be able to test the switch with boiling water and an OHM Meter.
Bad fan connection, broken wire.
If you have the radiator off, a radiator shop close by should be able to check the flow and stoppages for you and perform needed repairs, if they have small enough stoppers for the openings.
Are the water pump blades plastic or metal? With the radiator on and the cap off you will see water circulate when the thermostat opens. If not check your thermostat, again in boiling water and it should open as long as the thermostat is not in backwards, thermo spring should face the motor.
Passages may be blocked in the motor.
I am short on time and didn't read the thread as to what was advised or you did. Someone might have better advise.
Thanks from reading the posts I have the following list of things to do
Symptom - bike overheats rapidly, fan not coming on when hot, bike overheating with fan constant on
Done so far [X]
[X] Change oil
[X] Change coolant and flush system
[X] Make sure fan is operational with paper clip (fan is operational)
[X] Run bike with fan left constant on
[X] replace fan switch
[X] replace thermostat
In Process
[X] Check for radiator flow and clog (in process with radiator rebuild)
To do
[ ] test thermostat in boiling watter with thermometer
[ ] confirm coolant flow through hoses and engine
[ ] check water pump for operation
[ ] adjust carbs to make sure not running too lean
[ ] bleed air out of thermostat nipple
[ ] check spark plugs to look for signs off head gasket leak
[ ] Trace power source from thermostat to fan to see if there is interruption
[ ] try product rated to allow bike to run cooler than regular coolant
I would do these first.
[X] Check for radiator flow and clog (in process with radiator rebuild)
[ ] confirm coolant flow through hoses and engine
[ ] check spark plugs to look for signs off head gasket leak
[ ] check water pump for operation
Than this.
[ ] adjust carbs to make sure not running too lean
This appears to be a problem if the fan does not come on but it is not THE problem since you had it run constantly and still overheated
[ ] Trace power source from thermostat to fan to see if there is interruption
Shouldn't need this if your system is in order, to me, this is a band aide for a problem like this.
[ ] try product rated to allow bike to run cooler than regular coolant
If water flows, I would think bleeding of the system would not need to be done.
I agree completely that it will more than likely a coolant flow problem, but I have lost track if weather or not he has changed out the radiator cap yet; a bad cap could allow the system to boil over at a drastically lower boiling point than designed to. Possibly even boil over at a lower temp than the fan switch is set to come on. :shock: