NHBandit69 Posted May 18, 2004 Share Posted May 18, 2004 I need advice. '97 Blackbird is running routinely in the upper part of the temperature guage, and once the bike is turned off, leaks from the overflow in varying quantities. I have done the following/ made the following determinations: 1. Definitely from the overflow, not from a hose, join, etc. 2. Only after the engine is turned off. 3. Not due to overflow being too full, especially after what I found during the coolant swap, detailed below... 4. The fan is working, and does come on when the temp gets over the halfway point on the guage. 5. The water pump appears to be working, based on observed circulation through the open radiator with the bike running, and the hoses getting nice and warm as coolant circulated through them. 6. Other than the cooling problem, the bike runs great as far as I can tell. This past weekend, I drained the cooling system (and only came up with a bit more than one Honda pre-mix container of used coolant!!!!!!!), completely removed the thermostat at the suggestion of a mechanic at a local shop I trust (I know I'll suffer for that in the winter, but I'm trying to diagnose overheating here), tested the fan motor (it works), and then filled and "burped" the cooling system in accordance with the shop manual. Made sure everything was nice and tight and not leaking. Rode in today and all was well until I got behind a truck that impeded airflow. Even then, temp stayed at about the halfway point - until we hit traffic and a stoplight. Needle never hit the upper white mark, but got very close, maybe a needle's-widt of black between the needle and the white mark. Never rose above that, and came back down once I hit clean air on the highway. Normal pissing of coolant in the parking lot at work followed, although in drops and not streams. Air temps today were in the high 60's - low 70's. Pretty much duplicated the performance at lunch. Possible next steps I've thought of are Water Wetter, hooking up a manual fan switch to bypass the switch in the radiator and run the fan more - and I'm out of ideas. This CAN'T be normal. Local dealership charges $60/hour for labor, and an ungodly rate for parts, so I'm hoping to be able to fix this without going that route. Any ideas or suggestions? Quote Link to comment Share on other sites More sharing options...
xrated Posted May 18, 2004 Share Posted May 18, 2004 This may be a silly suggestion, but it is the only thing that comes to mind. Have you looked at the front side of the radiator. Are all of the fins nice and straight (not bent over)? Barring that, I would start checking the electrical circuit, as far as the sending unit putting out the proper voltage at the correct temp. , as well as the gauge. Quote Link to comment Share on other sites More sharing options...
Northman Posted May 18, 2004 Share Posted May 18, 2004 An engine will run hotter without a thermostat, than with. You need the restriction of the thermostat to slow the flow of coolant. That way, it absorbs more heat, and dissipates it better in the rad. Fast flowing coolant won't be as efficient. Put the stat back in, and refill the system. Let us know what happens. Quote Link to comment Share on other sites More sharing options...
speedygeezer Posted May 18, 2004 Share Posted May 18, 2004 Have you washed your radiator lately? Run water thru it from both directions as much as you can. Don't use a high pressure spray because the fins can be bent if you overdo it or get too close to them with the washer tip. If you've verified that the radiator fins are unobstructed with dirt or other debris, check to make sure that your thermostat is working. Plop it into a pan of water and bring it to a boil and watch for the thermostat to open and then close after you remove it from the heat. Some thermostats stick open too, so make sure that is not the problem. If all of the above is ok, next check your spark plugs. If they are white and dry, perhaps your carbs have gone lean on you - this will produce an overheating condition and cause the coolant to perculate out of the overflow due to excessive heat. As this cycle repeats, less coolant is available to do its job, and the problem intensifies. Pretty soon, the tops of the pistons will give up and develop holes in them. Quote Link to comment Share on other sites More sharing options...
SD Marc Posted May 18, 2004 Share Posted May 18, 2004 Time for a new radiator cap? Quote Link to comment Share on other sites More sharing options...
jrdxx Posted May 18, 2004 Share Posted May 18, 2004 And a damn fine job he's doin', too. Quote Link to comment Share on other sites More sharing options...
Lynx60 Posted May 18, 2004 Share Posted May 18, 2004 I second the diagnoses calling for a new radiator cap & gentle flushing of the radiator's cooling fins. You'd be surprised how much dirt & bugs manage to get lodged into those fins. Lynx60 Quote Link to comment Share on other sites More sharing options...
speedygeezer Posted May 18, 2004 Share Posted May 18, 2004 Curmudgeon - n. a churlish person. Churl - n. a surly or coarse person, a peasant. Churlish - adj. rude, surly. Surly - adj. ill-humored, ill-tempered. I never knew you were all of those things, Joe :roll: :wink: Quote Link to comment Share on other sites More sharing options...
NHBandit69 Posted May 18, 2004 Author Share Posted May 18, 2004 Thanks for all the advice. I'm going to start with the fin straightening and radiator washing, and a new cap. Then I'll progress on to the more advanced/ expensive solutions. The lean condition makes a lot of sense, as I have some doubts as to whether the previous owner rejetted for the Yoshimura exhaust on the bike. I'm already tentatively scheduled for a dyno run once I get the cooling squared away based on those suspicions; now I think I'll head down there once I get the fins straight and the new radiator cap. Thanks again for all the help; you guys are great! :cool: Quote Link to comment Share on other sites More sharing options...
daveszx302 Posted May 18, 2004 Share Posted May 18, 2004 What they said (cap and radiator fins) and I will also second the thermostat, run one! I would also check the oil cooler for any obsturction and run some Watter Wetter and just for the heck of it run a little Sea Foam in the gas tank, it will clean any carbon off the piston and intake valves, it works! -Dave Quote Link to comment Share on other sites More sharing options...
Dion Posted May 18, 2004 Share Posted May 18, 2004 ....... Plop it into a pan of water and bring it to a boil and watch for the thermostat to open and then close after you remove it from the heat. Some thermostats stick open too, so make sure that is not the problem. ....... Just expound on this, when you check the thermostat you want see what temperature it's opening at. Too low and you have the inefficient free-flowing situation to high and you're boiling. start out with a pan of hot tap water and a meat thermometer. Heat the water slowly and see what temperature the stat opens at. I think it should be around 170-180f but double check this. Quote Link to comment Share on other sites More sharing options...
speedygeezer Posted May 18, 2004 Share Posted May 18, 2004 Not to drag this out, but there is another possible cause for coolant depletion and that is a leak in the head gasket or a crack in the case. Check your oil to make sure it isn't milky-color. If the leak is large enough, you may also get some white smoke/steam out the exhaust. A small leak over time can cause the coolant loss. Quote Link to comment Share on other sites More sharing options...
Suf Daddy Posted May 19, 2004 Share Posted May 19, 2004 I'd replace the thermo, cap and try again. Speedy geezeer may have the hairline crack in the headgasket as a cause too. The circulation you see may be PERKulation from the headgasket being cracked. My old car did it. Run no traffic, no problem. temps over 85....no go: boil over. I can swing my Bird by, after I finish with the sprockets. -Suf Daddy Quote Link to comment Share on other sites More sharing options...
pacman Posted May 20, 2004 Share Posted May 20, 2004 It could be the antifreeze which is too strong! and if it is, the engine will run hotter for sure! :cool: Quote Link to comment Share on other sites More sharing options...
NHBandit69 Posted May 24, 2004 Author Share Posted May 24, 2004 New radiator cap and the rubber seal for the radiator cap on order from the local dealership. Will straighten my fins and top off the coolant before I put the new cap on, and let this thred know what happens. Expect the parts to be in just before the weekend; with the weather we're having in New hampshire this week, there's really no rush at all. :sad: Quote Link to comment Share on other sites More sharing options...
Dion Posted May 24, 2004 Share Posted May 24, 2004 May as well take the opportunity to flush and replace the coolant too Quote Link to comment Share on other sites More sharing options...
egadrotu Posted May 28, 2004 Share Posted May 28, 2004 Bump....keeping it alive as I have had exactly the same problem. I, on the other hand, may have slightly overfilled my overflow. Shut it off yesterday and could hear it boiling after a second or two. Not right away...only after having been off for a few seconds, about the time it takes to get off helmet and gloves and make it to the garage door. I waited till it cooled a little and added some coolant to replace any that might have boiled over. No problem on the way to work, but after I got home...boiling sounds, this time accompanied by a nice stinky coolant burp from the overflow. Let us know how yours turns out. Quote Link to comment Share on other sites More sharing options...
NHBandit69 Posted May 29, 2004 Author Share Posted May 29, 2004 Okay, here goes... Refilled the radiator, and bled the system again per shop manual, then sealed her back up with the new radiator cap. Took a lap of the city on the highway, and then dove in and took her through the city itself in traffic. Everything running GREAT, temperature guage never got much above the half-way point, fan came on when it should, and even when in stop-and-stop traffic, stayed well within normal operating temperatures. Of course, this was yesterday, and it was only in the mid-60's, but I was still feeling pretty enthused. Pulled in the driveway, shut her down, pulled off helmet, gloves, jacket, etc. Then I heard the dreaded gurgling noise... Was only rewarded with about 8 drops or so of coolant out the overflow, no steam. What the FUCK... Again, the temperature guage never got near the top of the normal range, much less near overheating, and was a bit below half when I shut down. Oil level is good, and not milky in the least. I'd almost understand if I had really heated up the bike, but she was running nice and normal. I would tend to think that a severely lean condition would show up as running hot most of the time. Ditto a water pump problem or blocked hoses. Looks like I now have the process of removing the right inner cover down to about a five minute process including bringing down tools (live in the 2nd-floor apartment), so if I'm relegated to weekly coolant-adding and radiator-bleeding sessions, it'll SUCK, but I guess I'll deal. I'll see what happens over the next couple of rides; not beyond the realm of possibility that it's actually fixed and I'll never see a drop of coolant again. If that's not the case, I guess I'll be looking into a visit with a local shop I trust that charges $40/hour instead of $60. I'll certainly keep this thread informed of what happens. Who knows, watch this space long enough, and you may get to see details on my conversion to a completely air-cooled XX... :twisted: Quote Link to comment Share on other sites More sharing options...
NHBandit69 Posted June 21, 2004 Author Share Posted June 21, 2004 Went to check if the siphon tube was kinked when I put in the new thermostat. Pulled on the tube to make sure I was tracing the right one - and the hose that moved behind the frame member didn't go anywhere near the overflow container! WTF? I started moving the tube that was indeed running to the overflow container, and found out it connected UNDER the filler neck, directly into the radiator. the shop manual calls this the air bleed tube, and it's supposed to be part of the pressurized part of the cooling system. Of course, this means that my radiator had a free and clear shot directly into the unpressurized overflow container... Swapped the two hoses to correct their routing, and haven't seen a drop of coolant snce. The thermostat does indeed have the bike running cooler on hot days; I never would have thought that. Yet another thing I've learned from this board. I had never touched these two hoses, so I have to assume this was a gift left to me by either the previous owner or their mechanic. The Pilot Sports with lots of tread that were mounted on the bike were a gift I am enjoying; this little present was driving me completely nuts. In any case, I'm all set now. Thanks for all the advice and help! :cool: Quote Link to comment Share on other sites More sharing options...
AZITPRO Posted June 22, 2004 Share Posted June 22, 2004 I'm in AZ and we have been having 107 deg days the last week. I ride an 03 and the digital temp guage has been diplaying 230 sitting in traffic and as high as 234. Quote Link to comment Share on other sites More sharing options...
Northman Posted June 22, 2004 Share Posted June 22, 2004 Great to see you finally got your problems sorted out, NHBandit. :grin: Quote Link to comment Share on other sites More sharing options...
birdrunner Posted June 22, 2004 Share Posted June 22, 2004 Bump....keeping it alive as I have had exactly the same problem.I, on the other hand, may have slightly overfilled my overflow. Shut it off yesterday and could hear it boiling after a second or two. Not right away...only after having been off for a few seconds, about the time it takes to get off helmet and gloves and make it to the garage door. I waited till it cooled a little and added some coolant to replace any that might have boiled over. No problem on the way to work, but after I got home...boiling sounds, this time accompanied by a nice stinky coolant burp from the overflow. Let us know how yours turns out. It happened to me too. I overfilled my coolant container on a cool day( It's only supposed to be approx 2/3 full. A week later when the temps got high, and I got stuck in traffic, I had a nasty coolant leak under my bike at the stoplight. I nearly cancelled my vacation because of this. Make sure you didn't overfill the reservoir, then take the bike for a ride and watch the temp gauge. If it doesn't go into red, you're OK. Let the bike cool, and check the levels again. Quote Link to comment Share on other sites More sharing options...
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