HELP with my RedTop 700 Yamaha!! Overheating/ Leaking anti-freeze

R

ryeguy2006a

New member
Joined
Dec 13, 2014
Messages
10
Location
upstate, ny
Hi guys,

I will start off with a little background. This is my first snowmobile, 1998 Yamaha XTC Deluxe 700 just over 3000 miles, and was really excited to start this season off right. Last Friday we got just enough snow to ride, and I have been chomping at the bit to get out. So, after a few short trial runs over the past few weeks in my yard and looking the sled all over(to the best of my knowledge), I headed out on the trails. After riding a few miles, I was very impressed with the sled overall. It has tons of power down low, really great top end, and great handling despite the limited amount of snow ~6". The only issue, if it is one at all, is that every once and a while it would "stick in gear" and when I let off the throttle the sled wants to keep going. As soon as I hit the brake I would hear the clutch click and it would come to a stop. I am assuming it is a sticky clutch or something. Anyway to get to the real problem, I ended up meeting at my uncle's house and I stopped inside his shop to get warm. I was checking over the sled, when we both noticed that the cylinder head looked distorted on the outer cylinders?? When we got to looking at everything, my coolant was low and appeared to be just slightly leaking out the belly pan near the water pump or front cooler.

I haven't touched it since last weekend, but am going to look at it tonight and see exactly what is going on. I was hoping to get a little advice after searching this site extensively. I am going to start with assessing the water pump and trying to see exactly where it is leaking from. I have read many bad things about the brass gear of death, as well as a mechanical bearing. I am hoping that it is something simple like a cracked hose, but from the sounds of everyone's posts doesn't seem likely.

Also, might be worth mentioning that the sled runs excellent, which is what surprised me. Also, no lights came on for temperature. All three cylinders were ~120 psi.

If it does happen to be the brass gear, how do I tell if it the motor is getting oil? Can I just bypass the oil pump by pre-mixing and possibly getting an electric inline water pump? On a very tight budget with a baby on the way, so a major overhaul is out of the question.

Plan for tonight:
  • Pressure test system
  • pull water pump cover
  • Assess any damage

Thanks,
Ryan
 
for reassurance
I got a 97 700 with 20000 miles on it and never had a problem with the brass gear , however I did have the impeller strip out on the shaft.It never leaked but did overheat. I suspect the seal went bad on yours . Not a hard fix. tear into it and replace it. of course you probably now have warped heads and should look for a new head ...try ebay! good luck!
 
Well that is good to hear!! I had read about the impeller stripping out on some sleds too. How did you replace that? Any pictures? Also, excuse my ignorance, but what seal? The outer housing seal or the inner mechanical seal?

Thanks,
Ryan
 
search up "mechanical seal" and look at the threads with pics, there are lots. i did mine 2 years agoand can walk you through it.
 
Could someone post a link to the threads with all the pictures? I have searched Mechanical Seal and only found 2 threads with any pictures. I would like to see what everything looks like before I tear it all apart. From what others said, I am hoping that it is just the washer seal for the impeller. I am keeping my fingers crossed. ;)!
 
Search water pump leak. Lots of info on here. Pretty easy fix. I had to lift the front of the motor to get at the bottom bolts of the water pump cover.
 
It's not a big job, undo the front engine mounts, jam a hockey puck under one and that should give the room to get your hands in there. It's pretty strait forwards, once you open it up you will understand
 
Thanks for all of the replies! I did get a chance to pull the pump cover off and everything appeared to be intact without anything out of the ordinary. I cleaned everything up and put it back together filling it with anti-freeze. Then when I got all the grease cleaned up on the bottom of the engine, I used a paper towel and placed it under the pump housing below the engine. I pulled the plugs and turned it over a few times then checked the towel. I appears to be leaking from behind the housing. Is that where the weep hole?
 
Seems like per everyone's recommendations and what I concluded from last night that it is definitely the mechanical seal. Does anyone have part #'s for the mechanical seal, washer, bolts, etc.? Or does someone make a "kit" that includes all the parts to do this job?
 
This is what I bought
90210-06001-00 WASHER, SEAL
8CH-12451-02-00 IMPELLER, WATER PUMP
11H-12438-00-00 SEAL, MECHANICAL
8CH-12439-00-00 O-RING
You need green locktite as well. Let it cure for at least 24 hrs at room temperature before refilling.
You may not need the oring seal for the pump housing, but I did, the old one would not go back in right because it had stretched.
I bought everything from partzilla.
 
now i rebuilt mine and it weeped a bit at first, then after some run time it sealed up. ive heard that you should also replace the shaft, as the seal mates with it wears a groove in it. i did not but that just me. i bought a new bolt as well because i wanted to give that little expensive washer the best chance possible to seal up. also beware not to touch the seal mating surface when you put it in, the oil on your fingers can cause the precision ceramic surfaces not to mate.... pretend your NASA building the Apollo 11 lander ahahahha.
 
Last edited:
Ok, I ended up getting the water pump housing off and pulled off the impeller. At this point I am sort of stuck. I am not sure what comes out or if I am actually looking at the mechanical seal. I have attached some pictures of the parts that I pulled off. With my limited knowledge of Yamaha engines, to me all the seals look to be in good condition. I know that some have mentioned that the leak can be from the loose fit between the splines and the impeller. I would greatly appreciate if people that know much more than me could take a look and help point me in the right direction.

What I think that I would do is get some of the Loctite 680 that most people recommend for this job, and try to seal the impeller to the shaft.

15742122894_8a43d4abc1_b.jpg


16178352609_ebfc28e234_b.jpg


16178352499_6090f4a970_b.jpg


15742121904_7443908f2a_b.jpg


Cheers,

Ryan
 
Ok, I attempted to fix the leak last night. I didn't have any Loctite, but I tried my luck with some gasket sealant. I figure the worst that is going to happen is that I will have to just tear it apart again... Which I am pretty good at by now because I have had it apart a few times. Anyway, I put the sealant on both sides of the impeller, where it rides on the shaft, the ceramic seal, the splines of the shaft, both sides of the washer seal and tightened it down. I let it sit overnight, and will fill it today. I am hoping that the leak was coming from the washer seal and through the splines rather than the mechanical seal. Time will tell. I am hoping to get it bled tonight and take it out for a test run. I will keep the thread updated.

Also, something that was interesting was when I was taking the sled apart I unplugged the overflow and nothing came out, yet it was full of antifreeze? I thought that was a little strange, so after struggling to get it out of the sled I got it on the bench and sure enough it was plugged up tight? I don't think that someone purposely plugged it, but I believe someone tried some stop leak on the sled and that is what plugged the line and overflow. Anyway got it all unplugged and re-installed. We finally have enough snow to ride, so I need to take advantage of it.

Best,
Ryan
 
Thank for all the help guys. The sealant did the trick! I am no longer leaking out of the weep hole! I put about 30 miles on the sled last night and everything was working just as it should.

Last night right after work I went out to the garage and I jacked up the rear of the sled so I could crack the bleeder. There was a hesitation, and then the antifreeze shot out like a fountain, then quickly put the bolt back in. I lowered the sled and cracked the one on the top of the engine, and that had no air in the line. After I let the sled warm up and verified no leaks on my garage floor and that I was circulating fluid, I took the sled around my yard. Came back and both coolers were hot on the sides. SUCCESS! after I let it run for about 10 minutes and checking for leaks every few minutes, I was confident enough to hit the trails. I checked the fluid level every mile or so for the first few miles. Initially the coolant overflow dropped about 2", but after that it didn't move the rest of the night.

Thanks for all of the help. I am so glad that it was only the antifreeze leaking through the washer seal and not the mechanical seal. If it wasn't for this site I would have probably tried to replace the mechanical seal and not tried this first.

Thanks,
Ryan
 
You must log in or register to reply here.


Back
Top