Hi,

I've just noticed my 2002 VN750 (only had for a couple of weeks) thermostat climb up to the 1st red line while i was sitting idle talking to someone, I immediately took off and the bike cooled down as soon as I started moving, my radiator res if completely full. I was just wondering if its normal for the bike to hit the red line because I am planning to ride it in to work and I do not want any engine damage from overheating at stoplights, Thanks for any input

Al

Hi Al,

My wife and I just bought 750's and I also ride a 1500 Vulcan water cooled and the one thing that comes to my mind is how old is the coolant? If it's not fresh I would change it. Keeping fresh coolant will make a difference for cooling. If you do change it and still notice the temp gauge rising...then I would look at the thermostat next. Just a couple of ideas.

Getting to the red line is not normal.

If you are stopped, you should also be able to listen for a fan kicking in. If you do not here the fan then that could be why the bike is heating up

Check you fan and ensure that it is working properly. That is the only thing that will stop the temp from climbing while stopped.

http://smileys.smileycentral.com/cat/28/28_1_12.gif

My fan does kick on, i dont know if it only kicks on at certain times but i know when i park and get off, the fan is going. I rode it in to work today (bout an hour trip) and it barely got past the midway point but i didnt have to sit at lights very long either and it was also only a nice 80 degrees this morning. It seems that while i am moving the bike will stay cool, I just noticed it climbed up to the 1st red line a couple of days ago while sitting in nuetral in texas heat for about 10 minutes (bike was already hot) but as soon as i took off it cooled down. I've put new coolant in and also realized there was entirely too much oil in the bike so I drained and put the appropriate amount in (can actually see a line in my window now). I dont know if having the oil filled up too high can cause problems or not but im willing to try anything at this point. Is there any further troubleshooting I can do to make sure everything is working? Thanks again,

Al

Hey Again,

Well I just noticed my coolant resevoir is completely empty so im assuming I have a pretty nasty leak somewhere. I will search around and see if I can find anything leaking, thanks for the help

Al

Hi,

I've just noticed my 2002 VN750 (only had for a couple of weeks) thermostat climb up to the 1st red line while i was sitting idle talking to someone, I immediately took off and the bike cooled down as soon as I started moving, my radiator res if completely full. I was just wondering if its normal for the bike to hit the red line because I am planning to ride it in to work and I do not want any engine damage from overheating at stoplights, Thanks for any input

AlNo, that's not normal at all. The fan should kick in just after the needle passes the half way mark. If it's working (and it sounds like it is) I'd make sure all the air was out of the system by using the bleed valve that's located either on the thermostat housing, or near it.

Hello Again

Another update, Appearantly im a moron there is no leak in my system the bike was just hot, whenever it cooled down the res was full again. I have checked the fan and it does come on at the halfway point on the temp guage. Where might I be able to find the thermostat on my bike? Thanks again

Al

Al,


Before you tear into the thermostat I would follow Ironman's suggestion and do a check of your coolant.

You'll need to remove the radiator cap (only when bike is completely cooled down) and see how much coolant is in the radiator. If it needs more then add it slowly until it is full ( Honda makes a 50/50 mix that works well). Also be sure that when you do this that the coolant in the overflow tank is at the correct level (between low and full level as marked on the tank cover). If you needed to add coolant you'll then need to release any air that may be trapped inside of the radiator and to do that you'll have to remove the gas tank to get to the housing where the release bolt is located (at the thermostat housing). If you do not have a manual I highly recommend that you buy one so you can see and follow the steps outlined in the manual so you do it correctly. If after you check / add coolant...and release any trapped air in the radiator...and the engine still overheats...then I would take a look at the thermostat next. Just my thoughts.

Thanks guys I've ordered a Clymers service manual will let you know the outcome after I get it

Al

You can also download a parts and maintenance manual from:

http://tocmanufacturing.com/toc.htm


If you use internet explorer, right click on a link and select "Save Target As.." because the files are large.

Running in the summer and the Arkansas heat here, my bike was running hotter than what I liked, especially if I got stuck in traffic. I added "Water Wetter" to my antifreeze and it does help the bike run cooler.
http://www.redlineoil.com/products_coolant.asp
Every little bit helps.

I think I posted this to your private message , but I am not on my home computer. here goes.

I live north of Dallas TX and commute 1 hour to work, and 1 to 1 1/2 hours back home in the afternoon. I just completed repairs 2 weeks ago.
The final solution appears for my 1986 VN750 appears in three areas.
1st Repair of very small high pressure leak in the radiator. I used JB WELD applied and let set for 24 hours before use.
2nd Over 20% bent cooling fins on the radiator. This reduced heat transfer capability. I could not fix.
3rd I took the radiator off bike filled with a CLR like compound let it set for 5 to 10 minures then flushed with water. That took out (lime?) build up in the radiator ( white milky stuff came out during the flush.)
Dallas Afternoon traffic in 100+ degree heat is harsh on the bike and the (51+ years young) rider. In those conditions of the afternoon after the repairs I get to the last white mark before the red line.
Actually I am on the shakedown cruise in far northeast ARK 600 miles so far. The results the bike cools flawlessly Mid point to high mid point in all situtations except Dallas 100+ degrees stopped in stop and go idling, even then it is not in the red. Good Riding,and good life.
Respectful Regards
Ed Rountree
1986 VN750 "Leonidas"
Lots of stuff Added I love that drivers Backrest.

Hello again,

Well I put about 300 miles on my bike today everything went great. I flushed my radiator and then adjusted the idle (was at about 2krpm prior) and while riding the thermo never made it to the halfway mark, at idle for a good while it barely passed the halfway point, I consider the job a success thanks for all the help.