I just bought a 2003 trailboss 330 atv. I have noticed that it has a slow leak coming from the crank case directly on the bottom where the 2 halfs connect. is there a way to stop this without removing the motor and disassembling? thanks

 

Welcome to the forum! You might try first to snug up the case bolts and also motor mount bolts that go through the cases and see if it helps any at all.Since there's not a case gasket,probably just a spot missed on silicone from the factory. First thing that comes to mind is any quick setting sealant such as jb weld or newer urethane epoxy sealants,but may or may not help.If nothing helps then depending on how much it leaks either keep a check on oil level or bite the bullet and split engine and reseal(Big pain I know,I've had to do this before!) OPT

 

Thanks old polaris tech. Thats what I was afaraid of. I did try to tighten up the bolts. and it still leaked. I then got some bars leake engine seal and put in. after that it didnt leak for the first nite until I rode it the next day then it started to leake again that nite. I may try some seal all on the outside of the case. thanks for your thoughts.

 

its been a while since Ive been on. im going to be getting back on this project pretty soon. is it possible to remove the engine and just loosen the bolt to both halfs a crack it just enough to put some gasket maker back in? if not what all do you have to do? thanks in advance.

 

No,you wouldn't be able to open the cases even a little unless you pulled the head and cylinder off to take the pressure off the case halves!If not you have a danger of cracking the cases if you tried to pry em open enough to try to reseal!(plus probably wouldn't seal and leak again) If you're going to pull the motor just do it the right way!Pull the head and cylinder,then all the case bolts can be removed from the right side. You can then tap on the cases at the places on the case designed to separate them. Have the engine on the right side (wont have to remove oil pump this way) and remove the left case leaving the crankshaft in place in the right half with the two bearings on the crank shaft. Clean the oil and excess sealant around the case halves(best to heat around the bearing area around the case for easier case seating of the two bearings on the clutch side) ,reseal with Three bond 1194 (replaces the old 1104 sealant) OR Loctite 518 engine sealant. Also you need to replace the left side crank seal!Tap the case back on all around with a dead blow hammer until it seats,turn engine back over on the left side then replace case bolts on the right side. Also a good time to check out /replace the rings if needed,plus clean the valve faces of excess carbon build up. Manual is highly recommended if you do this! OPT

 

wow thanks opt. thats a very insightful explanation. I have downloaded the service manual I believe. So I will begin pulling the engine for the repair in the next few weeks. I hopes its a straitforward as you have described. thanks.

 

Nothing is really straight forward as I sometimes describe! I have always been an "optimistic pessimist"
When ever I tear into anything,I always anticipated to find the worst,BUT when it wasn't that bad,I felt good after the job was done! OPT

 

as it turns out the manual I have is not for my trailboss. does anyone have a manual for my trail boss? thanks.

 

As long as it's for a 330 engine,doesn't matter if the manual is for a Trail Boss, Trail Blazer or Magnum the engines are basically all the same. OPT

 

thats just it... the manual I have is for a sportsman or xplorer. I dont think this will work.