1987 RM125....I”m a sucker for old Suzuki”s..

BenG
Profile picture for user BenG
Posts
228
Joined
12/20/2017
Location
Denton, TX US
BenG 7/14/2019 5:50pm
7/14/2019 5:50pm
sandman768 wrote:
I have a utube video of it running...need to have my daughter show me how to link it👍.... take your time & rebuild that bike you...
I have a utube video of it running...need to have my daughter show me how to link it👍.... take your time & rebuild that bike you have, parts are plentiful for them...your main areas of concern will be worn main bearing pockets in the cases & worn out shock body...I would get those 2 areas squared away first, after that most parts can be had oem or aftermarket. True story: a practice track I used to ride regularly was at an old dairy farm. In one of the run down barns was a complete but disassembled 81 or 82 rm125, I could have taken it home one day, but a I never did...likely still there, but property was sold and new owner could not get rid of us fast enough...
go to you tube video, click share, click embed, right click to copy then just paste to thread
Manbearpig
Profile picture for user Manbearpig
Posts
913
Joined
10/8/2008
Location
Edgewood, TX US
Manbearpig 8/7/2019 8:42pm
8/7/2019 8:42pm
Such a badass build man! Props on sticking it out. you've taught me a lot I appreciate it. My quest for an 87 continues! Turns out that pipe I acquired for an 87 rm125 is an actual Kehoe or Holland pipe that mitch built for team Suzuki. It gets back to me from Pro circuit tomorrow
dwhite645
Profile picture for user dwhite645
Posts
1
Joined
10/20/2019
Location
Lyons, GA US
dwhite645 10/20/2019 7:48pm
10/20/2019 7:48pm
quiknic wrote:
Sweet combo, I am looking to build an 88-90 RM-80 to go with our 125 & 250’s
I recently got an 89 rm80 project bike. It’s missing a few things but I’ve been able to find them all besides a cylinder barrel that with fit with the bottom end. Do you know anywhere where I’d be able to get one?
JohnPainter
Profile picture for user JohnPainter
Posts
18
Joined
10/27/2019
Location
Lewiston, ME US
JohnPainter 10/27/2019 7:45am
10/27/2019 7:45am
Does the ‘87 RM125 H/J model have steel or plated cylinder? I just picked up a complete bike $200, Other than mangled handle bars, in great shape though PO spray painted frame and engine black. Why do people do that? The issue is engine frozen so I pulled the engine and found left side crank bearing seized, not a bad fix, so as I’m going over the engine and listing parts I’ll need, I figured I’d try to clean up the jug but then wasn’t sure if it’s plated or iron.

The Shop

See All »
sandman768
Profile picture for user sandman768
Posts
8080
Joined
3/21/2014
Location
Saratoga Springs, NY US
sandman768 10/27/2019 8:28am
10/27/2019 8:28am
JohnPainter wrote:
Does the ‘87 RM125 H/J model have steel or plated cylinder? I just picked up a complete bike $200, Other than mangled handle bars, in great...
Does the ‘87 RM125 H/J model have steel or plated cylinder? I just picked up a complete bike $200, Other than mangled handle bars, in great shape though PO spray painted frame and engine black. Why do people do that? The issue is engine frozen so I pulled the engine and found left side crank bearing seized, not a bad fix, so as I’m going over the engine and listing parts I’ll need, I figured I’d try to clean up the jug but then wasn’t sure if it’s plated or iron.

The cylinders were not plated from the factory on these bikes, Hopefully it is not on the last over bore. These bikes had some issues from the factory, main bearing pockets wear, cases can be porous causing air leaks, poorly designed water pump impeller and cranks/rod that were not properly assembled. Find out why it locked up before just reassembling the top end.
1
JohnPainter
Profile picture for user JohnPainter
Posts
18
Joined
10/27/2019
Location
Lewiston, ME US
JohnPainter 10/27/2019 4:12pm
10/27/2019 4:12pm Edited Date/Time 10/27/2019 4:13pm
sandman768 wrote:
The cylinders were not plated from the factory on these bikes, Hopefully it is not on the last over bore. These bikes had some issues from...
The cylinders were not plated from the factory on these bikes, Hopefully it is not on the last over bore. These bikes had some issues from the factory, main bearing pockets wear, cases can be porous causing air leaks, poorly designed water pump impeller and cranks/rod that were not properly assembled. Find out why it locked up before just reassembling the top end.
Thank you, it doesn’t look plated but I wasn’t sure. The cases are in very good condition inside and out. The only missing piece is the rod to the power valves, but all the other parts are there. The piston is excellent I doubt it ever saw service.

There is a mystery. It’s clear the engine was rebuilt at least once, the screw heads show improper philips was used (not the correct JIS), the jug is in good condition, however the head has about a 1/4” band that looks like it was sand blasted with crushed rock.

I’m thinking there was a catastrophic ring failure (hence the new piston), the head was recycled but the jug replaced? Also maybe why the rod I was missing? When it was rebuilt a second time, maybe a chunk of piston ring got into that bearing and it seized and stayed that way till I got it?

I’ve inspected the gears and internals and it’s all excellent no chips, cracks, chunks, etc.




sandman768
Profile picture for user sandman768
Posts
8080
Joined
3/21/2014
Location
Saratoga Springs, NY US
sandman768 10/27/2019 5:45pm
10/27/2019 5:45pm
Something was floating around inside combustion chamber for sure! That head looks gruesome... inspect the lower rod bearing for missing bearing needles
1
bonseff
Profile picture for user bonseff
Posts
2050
Joined
3/29/2011
Location
Frisco, TX US
bonseff 10/27/2019 5:48pm
10/27/2019 5:48pm
That head has seen some shit
1
JohnPainter
Profile picture for user JohnPainter
Posts
18
Joined
10/27/2019
Location
Lewiston, ME US
JohnPainter 10/27/2019 8:13pm
10/27/2019 8:13pm
sandman768 wrote:
Something was floating around inside combustion chamber for sure! That head looks gruesome... inspect the lower rod bearing for missing bearing needles
Thank you. I looked all over, it’s very clean. Once I got the case off (bearing stuck to crank) everything turns smooth as butter, interestingly the lower rod bearings feel great, zero play up down very slight side to side spins smooth as butter. Something specifically happened to that one crank shaft bearing. It’s also a mystery why, if the jug got mangled like the head, why the PO didn’t swap both. I still think the pattern of the damage is interesting to the head, very fine like sand blasted in the center, deep gouges only around the lip.

None the less, I’ve got bearings, gaskets, a few parts etc ordered so I’m going put it back together. At this point I’ll have just under $350 in total into it. Fun project even if it blows up! 😃
JohnPainter
Profile picture for user JohnPainter
Posts
18
Joined
10/27/2019
Location
Lewiston, ME US
JohnPainter 11/1/2019 2:48pm
11/1/2019 2:48pm
Can anyone tell me what the ohm readings should be on the stator for 1987 RM125H.
OldHalfway
Profile picture for user OldHalfway
Posts
139
Joined
2/19/2018
Location
Pemberton, NJ US
OldHalfway 4/28/2020 8:15pm
4/28/2020 8:15pm
JohnPainter wrote:
Can anyone tell me what the ohm readings should be on the stator for 1987 RM125H.
Better late than never?





1
JohnPainter
Profile picture for user JohnPainter
Posts
18
Joined
10/27/2019
Location
Lewiston, ME US
JohnPainter 4/29/2020 8:06am
4/29/2020 8:06am
OldHalfway wrote:
Better late than never? [img]https://p.vitalmx.com/photos/forums/2020/04/28/424102/s1200_20200428_231216.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2020/04/28/424103/s1200_20200428_231229.jpg[/img] [img]https://p.vitalmx.com/photos/forums/2020/04/28/424104/s1200_20200428_231246.jpg[/img]
Better late than never?





Thank you, I actually figured it out and got things running and sold the bike. On to the next adventure!! Thank you.
1
kmuz700
Profile picture for user kmuz700
Posts
1
Joined
4/30/2021
Location
North Haven, CT US
kmuz700 7/15/2023 8:14pm
7/15/2023 8:14pm
CRFoot wrote:
I had a 87 RM125... I seized that thing at least 10 times. Finally took a factory mechanic to spill the beans and admitted the thrust...
I had a 87 RM125... I seized that thing at least 10 times. Finally took a factory mechanic to spill the beans and admitted the thrust washers/bearings were off from the factory. He changed them out and never had a problem. That was a long time ago so can't remember exactly, but I believe it was the washers.

funny you mention that, my 87 seized up the lower rod bearing....guess what, found it has a pro X rod kit in it. had hardly any hours on it too from what i can tell otherwise. So I finally pulled the motor, its going to Ken O'connor, the water pump side of the crank needs to be fixed too, and so does the top end damage from bearing trash going through the motor. Gotta love these old Suzukis! 

Pit Row

See All »

Post a reply to: 1987 RM125....I”m a sucker for old Suzuki”s..