Rm250 1988 low budget rebuild

Zzpzz
Posts
13
Joined
7/18/2014
Location
Federal Way, WA US
7/19/2014 1:06am Edited Date/Time 7/23/2014 10:04am
I was starting to takeover sandman768 thread so I figured I better start my own. I have too many questions to be messing up his awesome thread. I was looking for a project bike last year and found a cr250 that looked good but when showed up to look at it it turned out to be a nightmare ... Everything needed work ! He. Also happened to have a 1988 rm 250 that he was selling and it looked rough also but it had potential . Neither had been started in five years but "ran when parked". I got the pair plus two new helmets , gloves and two pairs of new boots for $500. It's been six month and I still haven't decided if I got a good deal. I sold the Honda a few days later ( after getting it running ) for $300.

I finally have the time to start into the RM250. I should have started with before pics but I forgot ( wasn't planning on having a blog on it ).

Piston looks good all except some light scoring . More than enough to need replacing though and the previous owner tried grinding the old head after an obviously catastrophic meltdown. Piston has no carbon on it and the exhaust ports are clean so it never go ridden after some work ... Not sure what though and none of it was up to par. I'm not a great mechanic but I do know that cutting corners never pays off ( well at least for long ) me and a friend once threw a Volkswagen motto together from spare old spare parts so we could run our sand rail at the beach the next day ( it ran for a couple weeks ) but that's another story.

So I got questions and who better to ask then the worldwide web. Some times just writing it down is enough.

First how do I decide if I should change bearings ... Can I calliper them or what ?

Everything inside the crank case looked pretty good to me visually . I did find one that had come apart but looked to be complete and fairly contained ( would have made a mess ) thanks to Sandmann768's suggestion that I break the whole motor down i found a couple issues that would have been catastrophic.

Second How much play should the rod have. It looks new

Third : Looking at the transmission what was the week point in rm250's what should I be looking for

And my final question is the grooves on the clutch basket can't tell if they have been filed down or are just rounded.

The link to photos is Nikon image space ... No pop ups or other junk.

Thanks I'll have to go get a manual for it ... Any suggestions on which one ?

If you don't have a cordless dealt impact gun... Ask for one for Christmas ! I forgot how handy it was I didn't have any issues with bolts or screws while stripping the bike down. It saved me hours of work ! Although be careful using it to put stuff back together especial if is aluminium.


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Zzpzz
Posts
13
Joined
7/18/2014
Location
Federal Way, WA US
7/19/2014 2:37am Edited Date/Time 7/22/2014 6:47pm
RM250 Tear down. Nikon image space I uploaded 90 pics or so... Most of them are so I remember where things go.

Issues so far:
Pitted cylinder head ( got a used one on eBay for $24 bucks )
Melted spark arrestor insert
No break pads on front breaks
The bolt that holds the clutch basket in was not even hand tight and caused some damage to the washer and bolt but hadn't failed completely ( thanks sandman768 ) that would have been a mess I think.
The bearing for the little shaft on the clutch basket face plate was coming apart I found ten and a half pins out of twelve so far.
My swing arm is cracked ( seems to be a weak point )
My piston is grooved a bit but my cylinder seems fine ( Ii will get it honed ) I'm at 67.3 mm
Front rotor Might be salvageable... it isn't grooved just ugly. Might be warped though.
Fork seals
Front tire has some side wall splitting from age.
Front and rear wheel bearings
Steering stem bearings

Things I want but don't need yet :
Seat cover
all plastic
Radiators are rougher than I would like but still function.
Back tire.

7/19/2014 4:54am
Low budget? Now that's my kind of build.
Will follow this with interest.
Zzpzz
Posts
13
Joined
7/18/2014
Location
Federal Way, WA US
7/22/2014 6:49pm
Can't see your photos.. can you use imgur or similar?
Can't see your photos.. can you use imgur or similar?
How about this....RM250 Rebuild Photos

The Shop

BigAl
Posts
266
Joined
7/7/2012
Location
Prichard, WV US
7/22/2014 7:19pm
Could you check the rotor on a piece of glass?

Were they plated from the factory?
Zzpzz
Posts
13
Joined
7/18/2014
Location
Federal Way, WA US
7/22/2014 11:37pm
BigAl wrote:
Could you check the rotor on a piece of glass?

Were they plated from the factory?
I tried laying it on a piece of glass and it's close but if you push on one side or the other you can feel it rock a little. I ordered a bunch of parts and a MANUAL. Hopefully the manual has some guidance. It's rusty and looks bad but it was worn uniformly and has no ridge. It's measures .115"(thickness) all the way around. I'll look for a used one and see what I can find. Dealer price is about $80 bucks.

Thanks for the glass idea at least let me know it might be worth cleaning up.

I have no idea on if they were plated or not. I'm guessing "not" looking at the uniformity of the rust. It may get refurbished or I will have to change the name of my thread. I'm spending cash pretty fast and that is on the broken stuff.

So far one lesson I have learned is to make sure you are ordering everything you need at once ! Shipping adds up quick if your breaking up your order! $15 dollar rookie mistake. The company I'm ordering from has lots of parts and gives me a discount but their shipping prices are out of line if you order one or two items.

My broken pile keeps getting bigger.





Zzpzz
Posts
13
Joined
7/18/2014
Location
Federal Way, WA US
7/23/2014 12:20am Edited Date/Time 7/23/2014 12:27am
So tonight I decided to break down the swing arm and rear suspension linkage . I'm going to need a lot of bearings ! Apparently dust , rust and water where the only lubricants added to the original Suzuki grease in the last 20 odd years !

I also was looking at the head and am guessing it has been sleeved ? I haven't got the manual yet ... But I thought they where plated cylinders and shouldn't look like mine.

I also got my $24 dollar cylinder head from eBay today " in condition good " , I would say "ok" or "fair condition" but it's usable and seems even ( not warped )

I will keep track of all purchases and post them when they arrive. At this point I ordered all the lower end bearings except the crankshaft bearings ,and one other left side bearing that was $68 dollars (mine seemed good still). I probably could have been cheap and left them all (except one that felt funky), but they where pretty cheap $12-20 bucks each . It will add about a hundred to my overall cost.






Zzpzz
Posts
13
Joined
7/18/2014
Location
Federal Way, WA US
7/23/2014 12:22am Edited Date/Time 7/23/2014 12:24am
Can't see your photos.. can you use imgur or similar?
Can't see your photos.. can you use imgur or similar?
Fliker RM250 rebuild Photos

I like the Flickr layout better ... hope this helps. Flickr gave me 1 TB of space FREE!
BigAl
Posts
266
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Location
Prichard, WV US
7/23/2014 5:16am
Chuck the rotor in a padded vice and use a 4" grinder with wire wheel to clean it up. If you have stuff plated send it out with the nuts and bolts.
BigAl
Posts
266
Joined
7/7/2012
Location
Prichard, WV US
7/23/2014 5:21am
Is that a gouge in the cylinder? I'd probably do a crank rebuild, bore and piston

Low budget may be out he window.
7/23/2014 5:23am
Flickr works nice - looking forward to seeing how this comes along. Those swingarm bearings... brutal.
7/23/2014 5:25am
BigAl wrote:
Is that a gouge in the cylinder? I'd probably do a crank rebuild, bore and piston

Low budget may be out he window.
Take a fingernail or even a dental pick and lightly follow the surface of the cylinder (perpendicular to bore). If there's a gouge you'll feel it. Boring is about $60 around here, and a piston kit will set you back another $125 or so. If I were going into the bottom end I'd probably freshen the top end for good measure.
Zzpzz
Posts
13
Joined
7/18/2014
Location
Federal Way, WA US
7/23/2014 9:48am
BigAl wrote:
Is that a gouge in the cylinder? I'd probably do a crank rebuild, bore and piston

Low budget may be out he window.
Crank seems like it was already done. Looking at my old head a lot of damage happened when this bike came apart last time. I think this crank is fresh looking at it and the hot rod. It also had very little play ( rod , the crank had none). A new crank bearing kit is only $50 but I don't want to replace "like new parts". I thought I would see what the book/ caliper says before rebuilding the crank.

I can see how these re- builds get out of control, there is always one more part you should replace. Logically it makes sense to spend $50 more. Water pump $50 , new crank bearings $50 , new rod bearings $50, and pretty soon $50 more is $500 more. It all seems logical until you get the bill, and it's more than the bike is worth.

Yeah ,I'm rebuilding the top end , I used my finger nail and could feel a couple gouges in the cylinder wall. I might hone it and see what it looks like. I'm trying to keep it "cheap" but I won't cut corners. one scratch feels deeper than the rest and is the only one I'm worried about. I'm thinking it's going to need to be bored. I have a cylinder hone sitting on the shelf so I might as well use it! I'm having a little trouble sourcing a piston kit though (I'm going to have to call the dealer ). So I read that I should have the new piston before I get it bored, but how do I know how big to go on the piston. Guess I'll find a shop and ask how they do it or have them look at my cylinder ( I'm sure they could tell just by looking at it).

The new cylinder head has a ding but it's pretty shallow and shouldn't be an issue to clean up. The gasket surface is smooth and hasn't been shaved as far as I can tell.

I'm on the lookout for a donor bike as I have too many parts that need replacing on the frame and buying a rolling chassis might pay off. I also am taking a drive over to a local motorcycle salvage yard ( never been ) I'm hoping it will be a wonderland of discounts ,and buried treasures. At this point I need a miracle to save my "Low Budget" title.

On a side note if you have access to Aafes online mall ( military ) they have a motorcycle parts vendor that is not to bad (price wise) you get a discount applied at checkout. The bad news is ,you can use your Star card for motorcycle parts ! Watch out for shipping though.

Zzpzz
Posts
13
Joined
7/18/2014
Location
Federal Way, WA US
7/23/2014 10:04am
Flickr works nice - looking forward to seeing how this comes along. Those swingarm bearings... brutal.
It could have been worse .... acid ... or melted and fused ... I still haven't been able to drive the bearing seats out. I don't think I have a salvageable bearing on the frame so far. I would have liked a photo of the look on my face when that dust cover came off and that bearing and dirt dumped on my workbench. I'm going to watch some youtube videos of finished project bikes and see if I can't ret back the spirit that bearing broke.

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