Yet another chump who wants to split his cases.

[Firechicken]

Before anyone asks me politely to use the search feature, I have read pretty extensively on this topic but am seeking some expert advice before undertaking it. I just bought a 99 blaster with a partially seized engine, it will turn over 1/2 rotation. I removed the jug and found that a piston skirt had broken and shattered into the case, no doubt wedging in places at the very least. Best case scenario is I split the cases and clean all the debri out and all is well. Anyway, I just want to split the cases to clean up and see the condition of the bottom end, if it's destroyed, I'm just going up part it out. What is the least I can remove to split the cases? I read somewhere that I can just pull the flywheel and sprocket and leave all the gears and clutch basket assembly on the clutch side and split from the flywheel side of the case. Is this accurate? I don't need to remove the crank, I just need to open it up and poke around and collect some piston. And I have a manual for reference.

Thanks in advance!

-Calvin

 

[dirtysquared]

Please use the search function. -------Sorry I couldn't resist.

Your going to have to split the cases to get the grenaded piston out.
I know of no way to just split the case from the flywheel side. Your going to have to just go ahead and split them as per the standard way

If you have a manual, there should be some procedure for disassembly. Check the cases for crack's or holes. Pieces of piston do some damage.

 

[Awk08]

The flywheel side case off first is the standard procedure, using a 2 jaw harmonic balancer puller. But both side main bearings and seals will need replaced to insure there's no shrapnel stuck in them. Just flushing the cases and not doing the bearings is like a crap game in a back alley, you'll lose

Look for videos in the engine section on splitting the cases and the KOR assembly vids, and the downloadable manual in general support section.

 

[Awk08]

http://www.blasterforum.com/threads/blaster-engine-disassembly-vid.42997/

http://www.blasterforum.com/threads/kor-engine-assembly-vids.51169/

 

[Firechicken]

I've been watching the videos and I have a manual, I decided to just do it (mostly) right. I removed everything from the clutch side. I am waiting on a flywheel puller in the mail then it will be ready to split. I'm going to attempt to split the cases without a case splitter. I know these methods are frowned upon but I'm going to try it anyway. If it won't easily seperate I'll buy a puller but I doubt I'll need it.

 

[nick20555]

I haven't had to use a case splitter in the 3 blaster bottom ends I've done. I have had to heat the crankcase to get the bearings out or heat the bearings to get them off the crank. I have also never been successful in sweating the bearings back in. They always seem to get wedged and heat up before I can get them in all the way. I have just had to press the outer races to get them in.

 

[OConnor Racing]

You can't split the cases properly without a case splitter or a harmonic Balancer puller. Screw drivers and hammers don't work. But what do I know?

 

[Markblaster]

You can't split the cases properly without a case splitter or a harmonic Balancer puller. Screw drivers and hammers don't work. But what do I know?

Dont you just hit the end of the crankshaft with a hammer to split the cases.

 

[Awk08]

Advance Auto and AutoZone both have loaner tool programs that you can get a harmonic pulled for just a refundable deposit. You may only have to buy the correct length metric bolts at Ace Hardware.

 

[Tooloose]

You can alwayz run over the engine with a DC-9 caterpillar and this will loosen up the engine a little, a just think of all the extra pieces you'll have! And think of how much time you'll save in disassembly

 

[Tooloose]

Then call Yamaha and order complete new engine and wallah! Problem fixed

 

[Tooloose]

Just think your hands won't even get dirty.

 

[Larry's Shee]

The one sold at Harbor freight even comes with the right length metric bolts

 

[Firechicken]

Update. Cases are split. I had to order the Yamaha flywheel puller ($10 on eBay). I rented a puller from auto zone but it didn't work for me. The shift shaft was pretty bent so it was a good time working that out. When it came to actually splitting the cases i didn't use anything but a pair of cautious American hands. I just wiggled it around, grabbing different areas on the case, it took about 2 minutes, no screw drivers or hammers required! The cases were full of shredded piston, all the bearings, the crank itsself, and the trans look good. Unfortunately when the piston granaded the piece of piston that found its way under the crank created a 2cm long crack in the bottom of the flywheel side crank housing. I'm still optimistic, it looks repairable. I'm going to try my hand at aluminum brazing. I have stick welding experience and I think this will be a fun learning opportunity. I've ordered a full moose seal kit and wiseco crank bearings. I've rebuilt top ends in the past but this will be my first full engine rebuild. What better to learn on than a blaster.

 

[Tooloose]

Hey just buy another flywheel side case off eBay it will save you some time and trouble Peace then you can work on your case when you get time

 

[nick20555]

When it came to actually splitting the cases i didn't use anything but a pair of cautious American hands. I just wiggled it around, grabbing different areas on the case, it took about 2 minutes, no screw drivers or hammers required!

Not trying to argue with Ken as he is the man and knows more than I will ever know (he is also the one that did the work on my current blaster) but when I said I have never had to use a case splitter on the 3 blaster bottom ends that I've done, what you said above^^ is exactly how mine went. Maybe I've just had some good luck but with those 3 bottom ends, it was as simple as lifting and wiggling like you said that separated the 2 cases. No hammers or prying. Now getting the crank off and the bearing off the crank was done cautiously with a mapp gas torch as Ken shows in his video's for installing the main bearings. Unfortunately, I've never been successful with INSTALLING them with heat. They always get wedged and have to come out before they seat for good. Luckily I got a press at our farm and can press the outer races of the bearings into the cases. I usually still try to heat the case prior to pressing them just to make it easier going in.

Enjoy your build! My first bottom end (and everything else for that matter) was on a blaster 7 years ago. Perfect quad to learn how to work on

 

[Tooloose]

I never had to beat apart , or dynamite , a case apart yet! I have had to bolt down the flywheel's side to a board with long bolts so that I could secure the engine properly while disassembling the clutch side and opening the case on Honda 4 strokes especially the oil pump pan head Phillips screws! Their so tight, I usually buy three or four impact bits from snap on tools

 

[Larry's Shee]

Don't be afraid of JB weld either.

Check posts by member "Best"
He's done some wicked repairs with it 11

 

[Firechicken]

Thank you all for the replys. I brazed the crack from both sides with aluminum brazing rod and mapp gas. It was tough to get the amuminum to temp, even with a mapp torch, but I'm confident in the repair. I ground the inside weld smooth and it looked pretty solid. My main bearings are in the freezer, I'm going to start reassembling the bottom end after work today.