1980 CanAm Mx6-125 rebuild

mxsixty
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mxsixty 4/9/2017 1:22am
4/9/2017 1:22am
This is awesome I've really enjoyed following this, can't wait to hear how it runs. You have done such a good job well done!.
Garand1
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Garand1 4/9/2017 5:50am
4/9/2017 5:50am
mxsixty wrote:
This is awesome I've really enjoyed following this, can't wait to hear how it runs. You have done such a good job well done!.
I really love rebuilding these old bikes(except when I cant find a part that I need :o) ) I get a kick out of young guys, (teens & 20s that are amazed by a bike thats air cooled and has twin shocks) I had talked to a guy who is big into following Super Cross that didnt believe me about the 70's Yamaha Monoshock suspension, that they were very successful in motocross. He thought they were only used in little scooter/mini bikes. But, its a lot of fun and gives me great satisfaction when I get them finished up. Its not 100% original, there are little tweeks here & there, especially when I see something i dont like and think "What were they thinking!!!) example is the original swingarm bushings.
Garand1
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Garand1 4/15/2017 7:40pm
4/15/2017 7:40pm
A bad week. Transmission was jammed up, so engine out and split....Found issue, fixed, reassembled cases..... Still jammed up.... Split it again.......Found a second bone headed move made by me....... Reassembled cases & it shifted.....OMG, I had to walk away from it for a few days. That's what I get for not watching the little details!!!!
Garand1
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Garand1 4/24/2017 4:59pm
4/24/2017 4:59pm Edited Date/Time 4/24/2017 5:10pm
I my shocks arrived today. I won/bought them on Ebay & was super excited to see how they would be and if they would work. I pulled the springs off to inspect the shafts. The shafts are near perfect, there is 0 leakage, good dampening and the length will be good also. The original shocks are 15.75" and these are 16.5" Fox gas shocks off a Arctic Cat snowmobile. Got the pair for $115 shipped. I'll run them as is for a bit and rebuild and freshen them up later. All I have to do on them is make some bushings to use a 8mm mount bolt

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riv187
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riv187 4/25/2017 7:44am
4/25/2017 7:44am
Garand1 wrote:
I my shocks arrived today. I won/bought them on Ebay & was super excited to see how they would be and if they would work. I...
I my shocks arrived today. I won/bought them on Ebay & was super excited to see how they would be and if they would work. I pulled the springs off to inspect the shafts. The shafts are near perfect, there is 0 leakage, good dampening and the length will be good also. The original shocks are 15.75" and these are 16.5" Fox gas shocks off a Arctic Cat snowmobile. Got the pair for $115 shipped. I'll run them as is for a bit and rebuild and freshen them up later. All I have to do on them is make some bushings to use a 8mm mount bolt
WOW thats different. I don't know anything about those shocks and really curious to see them and hear how they work for you!
Garand1
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Garand1 4/25/2017 12:28pm
4/25/2017 12:28pm
I believe I needed to go with a little longer rear shocks because of using the longer 38mm forks off the 400. They are a little longer than I wanted but I'll give them a try. I really wanted to use 16" or 16.25" but I saw these and thought Id give them a try. I had to do a little modding to the mount bushings, but not a lot.
450exc115
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450exc115 4/25/2017 12:37pm
4/25/2017 12:37pm
You'll probably find the compression and rebound to be too stiff. More spring and weight on a snowmobile than a dirt bike. I've used ATV and snowmobile shocks on a lot of my twin shock bikes. Cheap and work well with some tuning.
450exc115
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450exc115 4/25/2017 5:26pm
4/25/2017 5:26pm
Garand1 wrote:
I believe I needed to go with a little longer rear shocks because of using the longer 38mm forks off the 400. They are a little...
I believe I needed to go with a little longer rear shocks because of using the longer 38mm forks off the 400. They are a little longer than I wanted but I'll give them a try. I really wanted to use 16" or 16.25" but I saw these and thought Id give them a try. I had to do a little modding to the mount bushings, but not a lot.
Those forks are easy to shorten. All you do is lengthen the threaded portion with a tap, cut off the amount you want to remove and redrill the damper holes.
Garand1
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Garand1 4/25/2017 6:15pm
4/25/2017 6:15pm
450exc115 wrote:
You'll probably find the compression and rebound to be too stiff. More spring and weight on a snowmobile than a dirt bike. I've used ATV and...
You'll probably find the compression and rebound to be too stiff. More spring and weight on a snowmobile than a dirt bike. I've used ATV and snowmobile shocks on a lot of my twin shock bikes. Cheap and work well with some tuning.
I thought a lot about that. But one thing I figured is the bikes swingarm has a lot more leverage on the shock & spring. The shock is mounted in a laid down position on both, though I never measured the mount angles. But, the bike swingarm axle is well behind the shock mount. On the sled a-arm, the shock mounts just about at the end of(ski spindle) the a-arm. So it might be awesome, or it may be horrible. I was looking at a pair of similar shocks off a Sno-Cross sled with remote reservoirs & adjustable rebound & compression dampening, but they were considerably more money. Not saying it wouldn't be worth it, but I'm not a full time rider. So.x xif the dampening is off, I'll rebuild it & revolve it. The only modifications I had to do is come up with some bushings(14x8x21mm) and file a couple of mm off a section of the top of the shock above the mounting eyelet
Garand1
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Garand1 4/26/2017 5:25pm
4/26/2017 5:25pm
I mounted the shocks today and took the bike for it first little ride today and it ran really good. Only thing I noticed is it had no low end torque.....Of course I'm more used to riding my 400 and 88 Kx250....so, I guess that probably explains it. Any way, I was pretty impressed with it. Its probably been close to 15 years since Ive ran this at all. The fork seemed a little stiff, but, It would be better on a track Im guessing. The new to me rear Fox shocks actually felt soft in springs but decent dampening wise(I'm about 215 lbs) so I think I'll add some spring preload and see what that does. The only other I noticed is that I felt like I was shifting a lot.....again a 125 thing I need to get used to again.





riv187
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riv187 5/5/2017 8:21am
5/5/2017 8:21am
Nice build! Glad to hear it is running and you can enjoy once again. I remember mine having no bottom end too. It also had a electric feel with no powerband hit.
Keep us updated if you experiment with anything!
philG
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philG 5/5/2017 10:39am
5/5/2017 10:39am
80's 125 in 'no bottom end ' shocker

As was said to me ' if you are riding a 125 right, it could have nothing below 3/4 throttle, and you shouldnt notice ' lol.

Garand1
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Garand1 5/10/2017 6:29pm
5/10/2017 6:29pm Edited Date/Time 5/10/2017 6:30pm
Well guys, I ran into a major snag. A few weeks ago I took it for about a 5 min ride and was fairly hard on it. It ran awesome and I was very very happy with it. I pulled it into the shop and wanted to check the crown of the piston to see what kind of color & wash I was getting on it. So I looked down the plug hole with a bore scope and the piston crown looked really good, but something else caught my attention. The ring end gap was in the back transfer port. So, I took off the cylinder and checked the ring locating pin. The pin was there and in good shape, and then It dawned on me.... it was a piston for an earlier 125 engine with the 3 back transfer ports. I completely missed the end gaps were in the wrong place. Now, I'll bet this engine ran for 15 or 20 hours from when I acquired it. This cyl and piston is 2mm over. So I'm now in search of a cylinder sleeve. I've been in contact with LA Sleeve and they couldnt come up with anything except they can machine a blank and I'll have to cut in the ports myself. On a slight side note. I went to my parents house where I still many boxes of old snowmobile parts. I remembered having a couple std. 54mm pistons from a 1976 SkiDoo Tnt 250RV. And they will 100% work in the Can-Am 125.(the ring end gap is even in the right spot for my 1980 cylinder & they are 18mmwrist pins).
I've contacted some parts suppliers, RTR & VCP, & so far no luck. So I thought Id check with you guys and see if anyone has a line on a cylinder sleeve. I figured Id look for another week and if nothing I'l get the LA Sleeve blank. Maybe I'll get 4 or 5 blanks and cut the ports and sell them.
1
mxsixty
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mxsixty 5/11/2017 2:34am
5/11/2017 2:34am
Sorry to hear about the set back so close yet so far..
What do these bikes weigh? it looks so light there is nothing to.
wolfy0067
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wolfy0067 5/11/2017 4:43am
5/11/2017 4:43am
North west sleeve had made custom sleeve for me in the past, thing he is semi retire, check it out
Garand1
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Garand1 5/11/2017 6:39pm
5/11/2017 6:39pm
mxsixty wrote:
Sorry to hear about the set back so close yet so far..
What do these bikes weigh? it looks so light there is nothing to.
I think its claimed at 207lbs.....which was a little heavy for a 125 of that year i think. I think the Rm's & Yz's were around 190lbs
Garand1
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Garand1 5/11/2017 6:53pm
5/11/2017 6:53pm
wolfy0067 wrote:
North west sleeve had made custom sleeve for me in the past, thing he is semi retire, check it out
I will try them....The blank from LA sleeve would be $58, but then Id have to cut the ports, install it and have it bored to the piston. None of it is hard to do, but I'd rather just buy a sleeve or a cylinder. Ive seen lots of cylinders on Ebay but they are all the older style. Not sure if there is a difference in port timing, or hp, but i would think there is. I actually had thought about calling US Chrome to see if there was anything they could do with it. I wonder what the bore would be without the sleeve. There are many possibilities at this point!! ;O)

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Garand1
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Garand1 5/11/2017 7:03pm
5/11/2017 7:03pm
riv187 wrote:
`I suggest calling Eric Gorr. He told me he could nikasil plate my 78 RM125 which is also on it's final bore when time come. The...
`I suggest calling Eric Gorr. He told me he could nikasil plate my 78 RM125 which is also on it's final bore when time come.
The advantage is no port mismatch or changing heights that can happen with sleeves,,,longer life and staying 132cc for max power.

http://www.eric-gorr.com/index.php/services/services/2-stroke-services $225
Can you nikasil plate over a steel sleeve?? I still have a few more contacts to try, Remi at VCP thought he had a whole engine he would sell me, but I was under the impression that he thought it was in poor condition. RTR didnt have anything. I've gotta try Al Roberts & Tony Murphy yet, and there may be a few semi local guys I've been tipped on to try for parts. Thanks so much for the help & suggestions everyone......its very much appreciated!!
riv187
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riv187 5/12/2017 6:35am
5/12/2017 6:35am
Yes, you can nikasil over steel. Eric told me directly this 15 years ago,,and it's on the link I included. I have a trick ported 78 RM144, and was concerned what will happen when it finally wore out the last bore...I was at his shop getting it honed for upcoming race and he said no problem we'll nikasil plate it when time comes and it'll stay that size.
Seems easiest fix.

Garand1
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Garand1 5/12/2017 5:36pm
5/12/2017 5:36pm
riv187 wrote:
Yes, you can nikasil over steel. Eric told me directly this 15 years ago,,and it's on the link I included. I have a trick ported 78...
Yes, you can nikasil over steel. Eric told me directly this 15 years ago,,and it's on the link I included. I have a trick ported 78 RM144, and was concerned what will happen when it finally wore out the last bore...I was at his shop getting it honed for upcoming race and he said no problem we'll nikasil plate it when time comes and it'll stay that size.
Seems easiest fix.

I really like the thought of nikasil over a steel liner, I think it would be awesomely tough & durable. My one issue with that is back to the piston. The piston that I have is the wrong piston, and while I'd love to find another piston that would the 56mm bore, I litterly can find another 54 to 57mm piston that uses a 18mm wrist pin(other SkiDoo 250RV(type 245). Its 54mm bore, same wristpin, same height & wristpin spacing, and the ring is pinned in the right position. I did find a bearing that would adapt the 22mm bore of the upper connecting bore to 16mm wrist pins. Its a SKF bearing part# hk1622 16mmx22mmx22mm.



If I use this setup, I think the earlier YZ125 piston (56mm bore and 16mm wristpin) might work. The skirt is shorter than the CanAm piston, but wrist pin to piston top are close if not identical. And, I havent measured yet, but(I have both pistons to compare)Going this way may be interesting.

philG
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philG 5/16/2017 7:14am
5/16/2017 7:14am
Why not move the pin .. we used to do this years ago , we had a rake of pistons with pin out of place, used to redrill them and refit pin.. was fiddly, and obvs you need to blank the original hole.
Garand1
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Garand1 5/17/2017 7:10pm
5/17/2017 7:10pm
philG wrote:
Why not move the pin .. we used to do this years ago , we had a rake of pistons with pin out of place, used...
Why not move the pin .. we used to do this years ago , we had a rake of pistons with pin out of place, used to redrill them and refit pin.. was fiddly, and obvs you need to blank the original hole.
Guess I'm not sure what you mean by move the pin.
philG
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philG 5/18/2017 2:37pm
5/18/2017 2:37pm
The ring end position is determined by a pin in the ring groove..get it moved to where you need it.
Garand1
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Garand1 5/18/2017 6:37pm
5/18/2017 6:37pm
philG wrote:
The ring end position is determined by a pin in the ring groove..get it moved to where you need it.
Ok, LOL I see what your saying. Never even thought of moving the pin as I would be paranoid it would fail and then the engine would fail.......the engine that hasent been used since 1981, the engine that it is near impossible to get parts for :o) LOL!!! Thats almost like me being stranded on a desert island and having a gun with one bullet, but there's two tigers!!!
Shawbridge Husky 5/20/2017 5:22pm
5/20/2017 5:22pm
Good stuff ! Woosner has pistons for these got mine from Vintage Roost Alta. if I didn't mention it already. As for ignition I scored a low hour '82 Qualifier IV125 stator and cover, again from Alberta. ( huge vintage scene there ) Good tip on refitting the pin for piston ring end gap location will keep an eye on it.

Getting back to the stator mine comes with a fire box that is white in color ( nor black ) and uses an extra Violet wire. I think I'll be removing the fire box and moving the inner hub of the flywheel / keyway 8 deg. per the '82 factory bulletin posted in .pdf on canned ham. As that special hub that was made up for this remedy I'm think of just removing it off the flywheel rotor and machining in new threads at proper 8 deg. offset location and remounting. I'm guessing they only offered that new inner hub ready to go knowing not everyone one has access to machine tools and to make a more foolproof ready to go shop fix.

Thanks agan for the great thread hope to finally have at least one or two bikes running this summer.
Garand1
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Garand1 5/20/2017 5:50pm
5/20/2017 5:50pm
The shop I work at is a Wossner Distributor and I have asked them at least 3 times and they keep telling me they do not have a piston for them. Then I see a Wossner piston on Ebay. Do you have part #s for their pistons????
Garand1
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Garand1 5/20/2017 6:04pm
5/20/2017 6:04pm
Here's a video of the bike before I took the top end back off. It was running really good.
Garand1
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Garand1 5/21/2017 4:45pm
5/21/2017 4:45pm
Shawbridge Husky wrote:
https://cdn.shopify.com/s/files/1/0103/6192/files/Can_Am_Modifications…

https://vintageroost.com/collections/piston/products/vintage-can-am-pis…
Ive seen Vintageroost before but will contact them to see if they can help with my piston & cylinder/sleeve issue. The Mods I've also seen and may use that info once i get the cylinder issue taken care of. I'm thankful for all the help I've gotten while doing this build!!! Thanks to everyone!!!.

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