1981 rm 250 slow build thread...completed..

sandman768
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sandman768 3/31/2017 10:47am
3/31/2017 10:47am
Prepping cases for new bearings, clutch acuator arm does not want to pull out, no stopper bolt or circlip, Anyone know if these are supposed to pull out?



Case surface has some digs & imperfections, got most of them out, may have to use some yamabond when reassembling cases.

Heated cases & lightly dropped case half on wood & trans bearings dropped out, crank bearing moved a little, but required large socket to finish removal, left side crank bearing has no numbers on it.....bearing pocket looks good

sandman768
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sandman768 3/31/2017 12:23pm
3/31/2017 12:23pm


The right case half shows some some stress at the bearing pocket, some flaking of the case material, bearing was tight but looks like a crack is starting or would be soon. I have another bottom end coming so I will compare the two & take the best one, if I have to use this one I will have a welder inspect, maybe v it out & weld it around bearing pocket.
DT555125
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DT555125 4/1/2017 12:08pm
4/1/2017 12:08pm
Nice keep up the good work

harescrambled 4/1/2017 3:17pm
4/1/2017 3:17pm
sandman768 wrote:
Ed, it is a sickness.....I keep saying " this is my last one" but, I keep buying more....it's all good, could be into much worse things...
Ed, it is a sickness.....I keep saying " this is my last one" but, I keep buying more....it's all good, could be into much worse things. March snowstorms suck!
It's not a sickness...you get over those. It's a disease which has no cure. you can only treat the symptoms (get another resto project). I have 2 90's RM's, a RMX, a ATC200x, and just sold a resto 1995 CR80 not long ago, so I understand the disease progression

The Shop

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sandman768
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sandman768 4/14/2017 12:57pm
4/14/2017 12:57pm
Pretty happy with this 84 rm 125 wheel assy I found in eBay .... The 83-84 DLS wheels are getting hard to find...An 83 DLS brake hub assy came in a box of parts with this bike, bolts were frozen solid into alum actuator arms, but I was able to drill them out...going to refurbish the brake hub assy...this wheel is in vgcondition....does not even need bearings....



Craze
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Craze 4/15/2017 12:15am
4/15/2017 12:15am


I like Mine......1984 RM500 forks, wheel & triples
sandman768
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sandman768 4/15/2017 7:51pm
4/15/2017 7:51pm
Craze wrote:
[img]https://p.vitalmx.com/photos/forums/2017/04/15/188162/s1200_1981_RM250.jpg[/img] I like Mine......1984 RM500 forks, wheel & triples


I like Mine......1984 RM500 forks, wheel & triples
Nice looking bike....what's the story? Looks pretty clean....
rob.boucher.547 4/17/2017 11:46am
4/17/2017 11:46am Edited Date/Time 4/17/2017 11:49am
Check the diameter of your crankshaft( stator side) Suzuki cranks are generally undersize, for easy assembly
most likely your play will not go away after new bearings, seals etc

check how easy your new bearing fits on the crank end
I think the 81 RM's undersize crank journals caused all the bearing problems
in the case, on the ignition side
They are the best aircooled 250 suzuki once set up properly( but fragile)
Every suzuki i have had , when rebuilding, the case sets basically bolt together with very little effort

Not like a YZ , you have to use a puller to install a crank into the case, before putting together
sandman768
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sandman768 4/17/2017 3:10pm
4/17/2017 3:10pm
rob.boucher.547 wrote:
Check the diameter of your crankshaft( stator side) Suzuki cranks are generally undersize, for easy assembly most likely your play will not go away after new...
Check the diameter of your crankshaft( stator side) Suzuki cranks are generally undersize, for easy assembly
most likely your play will not go away after new bearings, seals etc

check how easy your new bearing fits on the crank end
I think the 81 RM's undersize crank journals caused all the bearing problems
in the case, on the ignition side
They are the best aircooled 250 suzuki once set up properly( but fragile)
Every suzuki i have had , when rebuilding, the case sets basically bolt together with very little effort

Not like a YZ , you have to use a puller to install a crank into the case, before putting together
The cases split very easy, I have not checked to see the fit of the new bearings on the crank ends. If this is the scenario, what is the fix?
rob.boucher.547 4/18/2017 9:47am
4/18/2017 9:47am
Purchase a higher quality german bearing set, from your local
bearing co.

Or rework your crank journal
flame spray
plating
weld and machine to size
sandman768
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sandman768 4/22/2017 10:06am
4/22/2017 10:06am
rob.boucher.547 wrote:
Purchase a higher quality german bearing set, from your local
bearing co.

Or rework your crank journal
flame spray
plating
weld and machine to size
Rob, you were spot on, I just checked the old crank bearings, they slide onto the crankshaft by hand and are pretty loose when on the crank. I already bought new crank bearings from my bearing supplier, who stated the new bearings are better quality than what I brought in. they donot slide onto the crank shaft by hand, I measured the I.D. Of the old vs new & the new bearings have a slightly smaller I.D.. Think I will be ok, what would be the smallest I.D. Bearing You could use, the O.D. Of the crank where the bearings ride is 30.00mm...? what piston did you use when you rebuilt yours? Single or double ring? I planned on using a wiseco double ring piston, but Oem single ring piston"s are still availible....thanks For your input Rob.
sandman768
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sandman768 4/25/2017 6:09pm
4/25/2017 6:09pm
My spare bottom end arrived in the mail today....got right on it....it was a pretty rough looking, but appears to have what I was looking for... But did not expect to find a load of beach sand in the clutch cover! The seller said the shift shaft would not return, assumed broken trans.... But the shift assy was packed with sand! Actually works good once cleaned out!






Almost have cases split, 3 of the case screws are frozen, , had to drill the heads off, thanks Suzuki, for using Phillips screws on the cases! I have to be careful, the frozen screws, thread into the rt case half, which is what I"m most needing out of this spare bottom end.....hoping the tranny has some usable gears as well.....but the rt side case is the main part needed...also dropped frame off to weld/ fab shop today, said he was all caught up with dirt track cars so he should be able to get frame repaired quickly...
sandman768
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sandman768 4/26/2017 10:41am
4/26/2017 10:41am Edited Date/Time 4/26/2017 10:43am
Spent all morning working on getting these cases split! Bottom dowl pin was frozen into cases, I managed to get the cases split, and 3 frozen case screws out without damaging either case! To my surprise, the bottom end has some very good usable gears, clutch basket,hub, pressure plate, shift shaft all good.







I have about 4 hrs into getting these 3 case screws out! Had to drill heads off to split cases, then carefully remove them from rt side case, which was my main part needed from this bottom end..

Main reason I needed rt side case, notice the big hole just below where the kick start shaft would be...thought about having it welded but spare bottom end likely very close in price & now I have a bunch of spare parts as well..
rob.boucher.547 4/28/2017 7:21am
4/28/2017 7:21am
Use stock pistons if you can find one, wiseco 2 ring set up also

Replace all the clips, ( kick idler gear, shaft clips) crank nut lock washer, clutch nut lock washer,screws,small shift springs, detent plungers, drain plug plungers, springs
use the eibach .47 front fork springs
MaxPower
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MaxPower 4/28/2017 8:55pm
4/28/2017 8:55pm
Where did you buy the new bottom end from?
sandman768
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sandman768 4/29/2017 9:06am
4/29/2017 9:06am
rob.boucher.547 wrote:
Use stock pistons if you can find one, wiseco 2 ring set up also Replace all the clips, ( kick idler gear, shaft clips) crank nut...
Use stock pistons if you can find one, wiseco 2 ring set up also

Replace all the clips, ( kick idler gear, shaft clips) crank nut lock washer, clutch nut lock washer,screws,small shift springs, detent plungers, drain plug plungers, springs
use the eibach .47 front fork springs
Funny you mention, using new clips, washers & crank gear nut washer....rt crank nut is reverse threads with special washer. Upon teardown I found a hole in the back of the case, as seen in my photos....then I see the rt crank nut is missing.....appears the nut came off & was tossed around for a while, then blown out the back of the case! All of which the previous owner failed to mention to me....I could not see the hole in the case as it was directly behind/ below the swingarm mouthing points...my bad......thanks again, Rob....
sandman768
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sandman768 4/29/2017 9:17am
4/29/2017 9:17am
MaxPower wrote:
Where did you buy the new bottom end from?
Got some help from....a gentlemen I bought a bike from some time ago....has/had many very nice RM"s....I believe he post on here occasionally....ibpassengas? He put it on his "sniffer" & found someone selling an 81 parts bike in Tenn. I was going to pick it up coming home from Fla this winter, but was too deep into Tenn. so, I asked the seller if he would pull the engine & ship it to me....the seller is a vintage enthusist also & agreed! Seller really went out of his way to get me the bottom end & was a pleasure to deal with....totally worth it, as The bottom end has a lot of very good condition parts, mainly good cases! Bonus for good trans gears, clutch parts.all electronics....I think The case could have been welded, but would have cost about the same as I paid for this complete bottom end... Spare bottom end parts on an 81 is very rare....
sandman768
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sandman768 4/29/2017 9:29am
4/29/2017 9:29am






Frame repaired....

Pit Row

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sandman768
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sandman768 4/29/2017 9:32am
4/29/2017 9:32am


Box load of parts to be glass blasted and soda blasted....good rainy day project....
sandman768
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sandman768 5/3/2017 9:37am
5/3/2017 9:37am
Did some soda & glass bead blasting yesterday....the slow process of prepping bolts, shafts, fasteners for reZinc is in process...cases are ready for bearing replacement & then refinishing.....still lots of prep work to do.....









rob.boucher.547 5/3/2017 11:52am
5/3/2017 11:52am
Build yourself a skid pan, and weld on frame tabs, they are worth it

sandman768
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sandman768 5/3/2017 6:21pm
5/3/2017 6:21pm
yes, if it's going to be a rider, I should get something under the frame....
ed webber
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ed webber 5/7/2017 8:13am
5/7/2017 8:13am
den where you getting oem suzuki parts,want to do the lower end on my 83 rm 125,are they still available?
sandman768
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sandman768 5/7/2017 5:33pm
5/7/2017 5:33pm
ed webber wrote:
den where you getting oem suzuki parts,want to do the lower end on my 83 rm 125,are they still available?
Ed, I use Rocky Mountain for Oem parts, their microfishe will show if a part is no longer availible. Hard to beat RockyMountain, sometimes I order parts & they are on my doorstep in 2 days. Parts should be plentiful for your RM, gaskets,seals are usually availible Oem from Suzuki, the rod may be a little harder to find. Another option for an Oem part that is NLA is a vintage Suzuki dealer in CT named "Paul Miller Suzuki", I have bought some NLA parts from him for my RM"s. The last few bottom ends I have done, I bought all Oem Suzuki gaskets & seals & took the old bearings to Kaman bearing & had them either match or upgrade the bearing quality for cheaper than Oem price. They are located near the Alb airport. eBay can also be a useful tool to see what is out there, I would type in " 1983 rm 125 nos" to see what pops up....I have bought some nice Oem NOS parts off eBay.....after a while you"ll see there are a few sellers that specialize in Suzuki parts. The tranny gears for all the old bikes are getting harder to find....if you plan on riding it hard, replace as many gears as you can get your hands on....post some photos of that beauty....
sandman768
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sandman768 6/20/2017 12:20pm
6/20/2017 12:20pm




Blew out some dents from the Oem pipe....pipe ready for sandblaster & works raw finish.....made skid plate & had my brother weld it in, we also chased footpeg & lower cradle welds before welding skid plate in. I just have to mount up cases to drill hole for oil drain bolt, then off to powdercoater for sandblasting & black powdercoat.








Dekon
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Dekon 6/20/2017 12:38pm
6/20/2017 12:38pm
Nice!
MaxPower
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MaxPower 6/22/2017 8:22pm
6/22/2017 8:22pm
I welded in a skid plate to my kx like yours. Used a large hole saw to strategically bore holes to lighten it some and allow mud to get out
I stuff a fuel cell type foam between the engine and the plate to keep mud from packing up
The KX frame is much much weaker than the Floater frames.
sandman768
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sandman768 6/28/2017 10:23am
6/28/2017 10:23am
MaxPower wrote:
I welded in a skid plate to my kx like yours. Used a large hole saw to strategically bore holes to lighten it some and allow...
I welded in a skid plate to my kx like yours. Used a large hole saw to strategically bore holes to lighten it some and allow mud to get out
I stuff a fuel cell type foam between the engine and the plate to keep mud from packing up
The KX frame is much much weaker than the Floater frames.




Like this? .....frame & pipe ready for sandblast & powdercoater....
sandman768
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sandman768 6/30/2017 3:21pm
6/30/2017 3:21pm


New engine case main bearing pocket inserts....nice & tight now!
chuckie108
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chuckie108 6/30/2017 5:47pm
6/30/2017 5:47pm
Looking good so far!

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