RM80 losing radiator fluid. Possible causes?


Chris Long

Member
Jan 17, 2005
33
0
I have a 2000 Suzuki RM80 that slowly but constantly drips radiator fluid out the overflow. The bike runs excellent and doesn't act like its runnning hot but it probably is. Even just putting around it always has a slow drip. After 2 hours of riding the fluid level drops down to the core. Not sure what it could be. I'm running Engine Ice super coolant, the outside temp was only 72 degrees and I wasn't running it hard. I also run 32:1 and a BR10ES plug. What are things that could cause the bike to run just hot enough to drip rad fluid but not hot enough to puke it out fast or casue engine running problems.

Thanks
 

Chili

Lifetime Sponsor - Photog Moderator
Apr 9, 2002
8,062
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If I recall correctly those RM's had a plastic impeller that tended to melt or get out of shape and stop working properly. Then the coolant isn't flowing it starts overheating. Another possiblility is a bad rad cap.
 

Chris Long

Member
Jan 17, 2005
33
0
Thank you for the reply. I've heard about the impellers. I'll check that out, but what would make a rad cap go bad? How does that affect cooling?
Thanks
 

Chili

Lifetime Sponsor - Photog Moderator
Apr 9, 2002
8,062
15
My bet is it's the impeller, friends of ours had to change theirs three times in 3 seasons of racing a 2000 RM80, they've had no troubles with the 03 the kid is running now. As for the rad cap not sure what would make it go bad, sometimes it just happens. I'm not smart enough to give you the run down of why a bad cap will make you lose coolant, just had enough experience racing to know that it's a potential problem :)
 

pandora95

Member
Apr 30, 2006
15
0
k i have the same bike and i kinda have the same problem we took out the impeller and it is rubbin against the case and i forgot but then there somethin worng wit a bearin wit ours i think we just had wtaer leakin into the oil,yes it dont over heat i just left it be and i cracked the bottom of my case some how where the oil plug goes and that has a good leak to we tried to jb weld it didnt hold but those rm 80s r diehards
 

Chris Long

Member
Jan 17, 2005
33
0
The impeller is a $14 item and the gasket is $3 at bike bandit so fortunatly its not a major cost to change every now and then. I will definatley order it and replace that. I'm also going to straighten out some of the cooling fins on the radiator as a few are bent.
 

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