ok all you 400 sport gurus out there... i need some help... to make it short i have a sport that slowly lost compression. Just finished an engine rebuild and its almost all done. My buddy and i went to fill the radiator and when we dumped fluid into it the fluid drained out the bottom of the engine. Right about where the starter is.

so what happened? i'm guessing that this isn't supposed to happen, and that this might be the cause of my engine blowing. It seems that all the fluid that was in the radiator drained out the bottom of the case, and so my engine overheated. so did i blow some sort of seal or did the water pump die? does anyone have any clue what most likely the culprit is? any help is appreciated... thanks!!

 

Is it draining into the case itself? Of is it coming out at the front of the motor?

 

we pored fluid into the radiator itself... it goes through the top of the engine down through it and it finally ends up coming out of the bottom of the case, about the middle of the 4-wheeler.... it looks to be coming out right about the spot the electric starter is at... and i think that the starter is fried too if that helps at all....

 

My memeory may be alittle shacky but I don;t think collant runs that far back. a couple things I would try.

remove the crank case drain bolt and pour the coolant in that bolt is close to the starter.

Did you replace the water pump seals? there is a weep hole were the water pump is it may be coming out the weep hole and flowing back along the bottom of the case and dripping. by the starter. Did you have counter balancer oil in it at the time? Is the oil contaminated? only other way I could think of it getting back there would be if a seal was bad (one closest to you looking at the engine from the recoil side) and running into the counter balancer area and out a crack at the case or through the seal behind the recoil starter into that cavity and out at the starter.

remove the recoil cover fill with fluid and see if you can see it leaking. otherwise you will may have to partially split the case

 

i guess i should go into a little more detail... when we pour fluid in... it takes a few seconds and then it comes out the bottom in a heavy flow... its not a drip it runs out as fast as i can pur it in. So does it sound like a seal around the water pump is gone? that was one of our guesses... we have to split the recoil apart anyway because the recoil cord snapped (it was getting old and chopped up)... the engine still started with the coolant problem... so it doesn't look like it affects that... but i didn't ride it or leave it on long because it will overheat of course... anyway thanks for the help.... i'll do some ripping and tearing and see what i find.

 

If I remember correctly it has a coolant drain on the water pump cover. You DO have it in don't you?

 

ok here's the dirt on what i think happened....

i opened up the recoil case (string broke anyway) and took a look to see what was happening.... when i did i noticed that the starter was loose... so i took off the skid plate and found out that there was only 1 screw still holding the starter in place... out of 4 screws. The rear bracket that holds it up snapped and one of the screws in the case rattled out... which leads to the next problem... ps.. starter it toasted... crap...

so the screw that rattled out of the front of the starter is my culprit... it bounced around inside the flywheel housing.... the fron of that housing has a wall that seperates the flywheel area from the waterpump area... well that little screw got thrown into the wall and put a pea sized whole in it. So my radiator fluid instead of being circulated properly was being pumped into my flywheel houseing... which in turn filled my recoil and starter with water...

so i figure my chain of events went like this... while riding and got to rough for the old girl and the bracket at the rear of the starter broke off... due to the extra stress on of the front bolts came out... while riding this bolt got tossed around scratching the case up until it hit the wall and put a hole in it cause my coolant to leak into my recoil case... which finally lead to a dead starter and engine overheat and lastly a recoil string that snapped in half...

man... what an unfortunate chain of events... but happily i have found the cause of my troubles!!! yeah for me!!

so my final question is this... what is a acceptable way to fix it? the case i believe is aluminum and welding it isn't easy... i could get that done which is probably the smartest choice... but i was wondering if using something like B-J weld would work... the radiator cap says it pops at 13 psi.... so would something like J-B weld hold that pressure reliable? if now will something else or do i have to go get an aluminum welder? if anybody knows please post it... thanks again.

 

weld would be best. JB mightwork I have no idea about the pressure but it is supposed to be ok to use to stop a radiator from leaking so I would think pressure would be ok. Its one of those your call things.

I personally would try the jb weld and see if it works. If you have a angle grinder or some good shears you can make a starter block off plate and do away with the starter. OR you can get one from HPD, AAEN RCR.

I have a working starter I might be willing to sell as well.

 

I put in a second vote for the JB weld. That stuff is very strong. I've had a Jeep distributor mounting ear(aluminum) reattached by JB weld for about 2 years without a problem. Be sure to apply the JB weld liberally, and spread it at least an inch around the hole on both sides. That should seal the hole no problem.

 

two bad it won;t stand up to soaking in fuel I have had it break donw on me trying to do this.