Valin Posted July 28, 2010 Report Posted July 28, 2010 I just filled the coolant for the first time after my build, and it appears as though I am having a coolant leak, coming from one of the case studs / nuts underneath the motor. It is leaking from a stud that is threaded into the upper case half, beside the center bearings, and travels through the bottom half. Here is where it is leaking from (yes, I know it's a terrible picture): It looks as though there is a coolant cavity that is between those two studs, and possibly I may have a void in the 3 bond. I can't see what else would cause coolant to leak from there. Here is a picture of the bottom of the upper case half. The stud in question is the lower stud (in the picture), in the center journal. Any input? Quote
hercalmighty Posted July 28, 2010 Report Posted July 28, 2010 Did you make sure you put the coolant plugs into the bottom of your cylinders? There shouldn't be any coolant going through your cases. It might be a good idea to put your motor together and do a leak down test. Quote
pabansheematt Posted July 28, 2010 Report Posted July 28, 2010 I just filled the coolant for the first time after my build, and it appears as though I am having a coolant leak, coming from one of the case studs / nuts underneath the motor. It is leaking from a stud that is threaded into the upper case half, beside the center bearings, and travels through the bottom half. Here is where it is leaking from (yes, I know it's a terrible picture): It looks as though there is a coolant cavity that is between those two studs, and possibly I may have a void in the 3 bond. I can't see what else would cause coolant to leak from there. Here is a picture of the bottom of the upper case half. The stud in question is the lower stud (in the picture), in the center journal. Any input? Did you have the clutch cover off? If so, did you replace the o-ring on the tube that goes into the clutch cover. If that o-ring leaks. It will leak coolant onto the motor and it will run through the little hole in the case and give the appearance the case are leaking. Hope this helps. It happend to me once. Quote
KlotzBanshee Posted July 28, 2010 Report Posted July 28, 2010 Are you sure its not just leaking from your "head to clutch cover" hose and running down the center drain hole and onto the stud? There shouldn't be any coolant in the case unless you didn't seal the halves up good or you may be missing the coolant plugs under the cyls as mentioned. What in the hell is that brass looking thing in the middle of your crank tunnel? Quote
J-Madd Posted July 28, 2010 Report Posted July 28, 2010 Anything liquid that gets on top of the motor (water, gas, alky, beer, whiskey, piss) will always run down those studs making it look like that it is leaking there. I assure you 100% that it is not coming from that stud. Quote
Valin Posted July 28, 2010 Author Report Posted July 28, 2010 Did you make sure you put the coolant plugs into the bottom of your cylinders? There shouldn't be any coolant going through your cases. This is a Cheetah motor. Did you have the clutch cover off? If so, did you replace the o-ring on the tube that goes into the clutch cover. If that o-ring leaks. It will leak coolant onto the motor and it will run through the little hole in the case and give the appearance the case are leaking. Hope this helps. It happend to me once. Thanks for that. Yes, this is a new 421 Cheetah build. I looked at it closer, and you are correct. It does look like it is coming from that o-ring location. There is a brand new o-ring in there, but obviously there is an issue. I'll have to pull the cover to figure out what is going on. Thanks for the tip. What in the hell is that brass looking thing in the middle of your crank tunnel? That is a pulse line fitting that I installed in case I end up running a fuel pump setup. Quote
pabansheematt Posted July 28, 2010 Report Posted July 28, 2010 This is a Cheetah motor. Thanks for that. Yes, this is a new 421 Cheetah build. I looked at it closer, and you are correct. It does look like it is coming from that o-ring location. There is a brand new o-ring in there, but obviously there is an issue. I'll have to pull the cover to figure out what is going on. Thanks for the tip. That is a pulse line fitting that I installed in case I end up running a fuel pump setup. glad I could help. Quote
Valin Posted July 29, 2010 Author Report Posted July 29, 2010 Pulled off the cover, and still really can't understand how it can be leaking from that area, with a new o-ring in there, so I sealed it all with Ultra-Grey. Problem solved. Quote
camatv Posted July 29, 2010 Report Posted July 29, 2010 i always smear ultra grey on the clutch cover on that part i think it does a few things i think it helps theo-ring slip into the clover and helps seal ANY small leaks that might develop. the NEW o-rings is a weird size anything other than the factory yamaha o-ring seemed to not work right for me. would always endup leaking, ear on install, or seap into the trans area. Quote
papa-smurf Posted July 29, 2010 Report Posted July 29, 2010 (edited) sorry edit Edited July 29, 2010 by papa-smurf Quote
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