MM800
Member
Thinking about building a jig to be able to seperate and press the Yamaha cranks. Does anyone have any info on this
mopar1rules
Active member
There is a company out of new york, that sells the tools/jigs/etc, but I don't recall the name of them. I HATE doing cranks, so I leave them for my local guy to do for me.
taylzee
New member
I would say go for it. It's not rocket science...but real close to it! If you are a machinist and have the right tools, I would say nor prob!
03viperguy
Moderator
I WISH I had the ability lol! I say give it a shot, if you want to
I have rebuilt dozens of cranks over the years. Have not had to do a Viper yet but if you plan on doing it fell free to PM me and I will send you my phone number.
Its not rocket science, just need to be patient and use a dial indicator. (they are cheap all over) Get it close as you can out of the case and put it in. Then mount dial indicator so you can check end of crank. Hit lobes (big counterweight looking things) on crank with brass mallet until everything lines up and you get the runout on end of crank.
Last one I did was a single cylnder motorcycle. Guy in machine shop said we don't do those. I asked him if I could use his press, and he said better yet to show him. LOL, maybe a minute to press apart and back together. Wonder if they do them now?
Put it in the case and a couple whacks with brass mallet and ready to go!
Its not rocket science, just need to be patient and use a dial indicator. (they are cheap all over) Get it close as you can out of the case and put it in. Then mount dial indicator so you can check end of crank. Hit lobes (big counterweight looking things) on crank with brass mallet until everything lines up and you get the runout on end of crank.
Last one I did was a single cylnder motorcycle. Guy in machine shop said we don't do those. I asked him if I could use his press, and he said better yet to show him. LOL, maybe a minute to press apart and back together. Wonder if they do them now?
Put it in the case and a couple whacks with brass mallet and ready to go!
mattyg1405
New member
the first time i brought a crank to get trued after i pressed it i watched this guy start whacking it with a hammer lol i was so confused i thought it was a special tool or something NOPE! a big brass hammer, and he had a jig set-up for the run out and etc... this was for a single cyl motorstingray719 said:I have rebuilt dozens of cranks over the years. Have not had to do a Viper yet but if you plan on doing it fell free to PM me and I will send you my phone number.
Its not rocket science, just need to be patient and use a dial indicator. (they are cheap all over) Get it close as you can out of the case and put it in. Then mount dial indicator so you can check end of crank. Hit lobes (big counterweight looking things) on crank with brass mallet until everything lines up and you get the runout on end of crank.
Last one I did was a single cylnder motorcycle. Guy in machine shop said we don't do those. I asked him if I could use his press, and he said better yet to show him. LOL, maybe a minute to press apart and back together. Wonder if they do them now?
LOL matty, I never let customers watch me align a crank as they about pee there pants when you start slamming at the crank with a hammer....
I have a crank right now that I'm going to attempt to rebuild. I have the press and tools to separate and reassemble, the dial indicator to measure runout but can't figure out a way to make sure the crank is indexed at 180 deg(it's a twin). Anyone have any ideas. I was going to try and make a jig or alignment tool.
who owns the ski doo 
yup you need to do your own cranks that often. a fellow rider did a crank on a doo triple last year . had 2 k on it 
yup you need to do your own cranks that often. a fellow rider did a crank on a doo triple last year . had 2 k on it Yup, it's from a skidoo all right. My fathers sled. It's an older machine. I have all the bearings just need to split to get the center ones off.
Jay I would think as long as the runout is within a couple thousandths I would think that your 180 mark should fall into place.
Bazaromcmullen
New member
You can always put in case and put piston and head on and use a piston stop and degree wheel.
Good idea about the case but the problem is, you need to have it set to 180 before pressing back together and I can't think of anyway of putting it in the case before its pressed together. I'll see if I can get some pictures tomorrow.
Can't you just scribe a mark on it before you split it and then just line them back up when you press it back together? Or have you already split it?
No not split yet. I have already done the scribe mark and hope that works. Only issue is that you won't know for sure until everything is pressed flush. If its not lined up it will have to come apart and be pressed again. Also, this assumes that is correct now. I'd just like to find a way to verify that both rod pins are 180 deg apart.
I know that you would have to put it together first but you could use your timming marks and a dial indicator to find TDC on each cylinder. That would tell you if your crank is in faze.
You may have to put degree tape on.
joehunt said:
So, basically you mean that after crank has been pressed together, put the crank in the case and put your cylinders on to verify that it is correct? Kind of a temporary assembly just to verify? Would you use a degree wheel on the crank end and then a dial indicator on the piston to read TDC?
Well, I have the crank pressed apart, just trying to get the gear that runs the warter pump/oil injection, off. Its being a bugger. I need this off the get the bearing on the other side of this off.