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My CR85 -- Yeah!

51K views 90 replies 16 participants last post by  aarontillison 
#1 ·
Well how shall I start this? Umm I knew I wanted a 2-stroke mini to ride around with my brother on his SSR140 and thanks to some friends on here I ended up with a 2003 CR85 I picked up for a cool $400 :D

She was in bad shape to say the least, but I was excited to take on this project first time for me. As soon as I got the bike home, put it on the stand and began taking it apart. So soon that I did not take a before picture :( , but I digress. I wanted to strip the bike down to paint the frame either red or black, and put everything back tighthen all the bolts replace all fluids, basically bring her back to a respectable state. Thus it began..

Where I was when I first thought to take a picture(s)


Big parts off, ready to be cleaned or thrown away. I got rid of all the plastics, I'm thinking of going either black or white plastics.


In a mess there is only a thrown. This is where I thought, what did I get myself into. Lol


Cleanish parts.



Something about noise emission, oh government! :arsenal


I went red!


New goodies! Purchased, new bearing, seals, bars/grips, sprockets (stock 14? up front and 47 in the rear), new gold chain :D , new top end.


Got bored one night and decided to piece er' back together. Worked from about midnight to 5:30am. :D I later realized the shock was backwards. Doh! The two mistakes I made was the shock and I put the subframe on before installing the airbox. Everything else was not too bad.


And as she stands now.


Clearly I am not done, infact I've only started. Next up is the conversion ! I want to get plastics before looking into all the SM goodies, although my family/friends like the naked look. o_O and I'm looking for some used SM wheels 12" or 17" I'm indifferent so long as the price is right.

Now I haven't got her running right, I'm hoping its something rather small and not a tear down all over again. It takes several kicks to get going and I have to give her some gas but then she will idle well and the motor itself sounds good no odd noises. Put her in 1st -- stall. Unless I really get the RPMs going and feather out the clutch it will stall. Once she gets going she runs like a champ! Riding a 2t is like learning to ride ALL over again, seriously! And she spits oil out where the exhaust connects to the motor, but I think this is the gasket or spring as I reused the ones that were there. All in all I'm diggin it! Thanks for all the help dudes!

Diego
 
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#34 ·
She lives! So after a while of being discouraged by the fact I F'd up the case being so stupid, I said I need to at least try and get this to work. Worst case scenario, I'll get a new one right. So I took a file and lightly filed it down til it was smooth on all rough parts, and had to JB weld a small crack. But it holds oil!

So hear this, I put it on and I get ready to crank it up and I noticed the kickstarter sticks at the bottom. Boy genius forgot to load the spring for the kickstarter, take it apart again and load up the spring. Then putting the cover back on, I overtorqued a bolt and broke it in the case. :headshake Yep, I thought about buying a new engine that night but there weren't any on the bay in my price range. So I had to call in reinforcements, ... my father is a disel mechanic and has broken a bolt or two himself in his time. So he showed me how to drill and tap it! Got it back on tonight, changed the oil and started her up. I messed with the idle screw (which was backed wayyy out) and it starts a lot easier now.

Really bad news is it's smoking like no other, I'm thinking the oil is mixing with the antifreeze because a little oil is coming out the overflow in the radiator. :/ I noticed what looked like a seal going to the transmission a little lodged out but since it was already like that I didn't mess with it. Probably going to have to take the cover off AGAIN. and see :damn: . Oh and when I put it into first, automatically shuts off but I think that a little adjustment of the clutch will fix this because it is backed all the way out. I hoope, I want to save the money to get a big bore but all these headaches are piling up. And stoping me from buy other goodies for it, its still naked!

I'm going to try and get a video so you guys can see what I'm working with, the smoke is really a show to witness! Well alright sorry for the long read.

Diego
 
#35 ·
If your getting anti-freeze i the oil the clutch plates might be rusted together. put the bike and gear and try to push it with the clutch pulled. If it does not push like its in neutral the clutch is froze. I had a friends KX100 do this and we just bump started it and rode it for a while and the clutch was free after a few a short time. Rode it around for a about a hour after that and then changed the tranny oil it was very rust colored fron the clutch plates. It works now but might need a clutch soon.

You clutch basket looks good from the photos.
 
#36 ·
Yeah it rolled and on a stand I put it in first and it will roll; but something bad has happen that I dont think I wanna fix with all this smoke coming out the exhaust. I think Ill get a known runner off the bay and move on from there. It will slow up the sumo process but I just wanna ride lol. I got to do a top end job on this motor and got a good look at how the clutch works and how to save a case I Fd up! Lol that was fun but I need to move forward.
 
#37 ·
Dudes! Slapped on some 12" wheels I snagged off here from a super dude! I'm diggin it. Also got my plastics in from the motorcycle superstore. I thought I ordered a black Acerbis kit but apparently they don't even have those at the MCS. So I'm stuck with red. :/

Got a short little video so you guys can see what I am working with. I paid $400 shipped for the wheels and snagged a engine off the bay for $300 so I am staying within my "don't pay more for an accesory than you did for the bike." motto :D

Excuse my pitiful kickstarts, I find it hard to kick her over with the tiny little kick started and on the stand.

Video: http://www.youtube.com/watch?v=vPD5lFLqjE4

Thanks.

Diego
 
#38 ·
Dudes! Slapped on some 12" wheels I snagged off here from a super dude! I'm diggin it. Also got my plastics in from the motorcycle superstore. I thought I ordered a black Acerbis kit but apparently they don't even have those at the MCS. So I'm stuck with red. :/

Got a short little video so you guys can see what I am working with. I paid $400 shipped for the wheels and snagged a engine off the bay for $300 so I am staying within my "don't pay more for an accesory than you did for the bike." motto :D

Excuse my pitiful kickstarts, I find it hard to kick her over with the tiny little kick started and on the stand.
Video: http://www.youtube.com/watch?v=vPD5lFLqjE4

Thanks.

Diego
I'm sure the mandals (man sandals) dont help.

but really, it confuses me also. but i am not a 2t guy at heart.
 
#39 ·
HaHa, yeah. I remember once I was trying to kick over my old RMZ with some water shoes. The kickstarter went right through those suckers.

Anyway, I won an CRF450 front brake today on ebay for $44 so thats on its way, and my new engine will be here Tuesday. Where can I get the bigger rotor/adapter?

Oh and did anyone have fitment issues with their forguards and the 12" wheels, it wants to rub tires?
 
#41 ·
Sweet! Thanks TM! Im so excited for all the goodies to come in! Rip around town. :D Tuesday I get the engine and front brake set up from the 450. :bannana:
 
#42 ·
Damn, looks like I jumped the gun and bought an 2003 front brake set-up anyone know if that bracket is backwards compatible? I know the 2003 brake works on the 2004-2006 450.

Anyhow she is engine-less and ready to get a new engine dropped in; hopefully tomorrow after class! Gents.
 
#44 ·
Fugg it, im gonna roll the dice on it. Of amything Ill buy another caliper and hook it up.
 
#45 ·
Amigos: Check it.



Looking for some graphics at the moment, and the AR bracket. I hit the fork guards with plasti dip and I like the look, but I will have to see how they hold up. Thanks for all the help too dudes.
 
#46 ·
Amigos: Check it.

Looking for some graphics at the moment, and the AR bracket. I hit the fork guards with plasti dip and I like the look, but I will have to see how they hold up. Thanks for all the help too dudes.
That thing came together, it looks good. Gotta ditch that front fender, though! All of the plastics companies (UFO, Acerbis, etc.) make smaller supermoto fenders that will look much better with the 12" wheels.
 
#48 ·
Thanks guys. Im def going to try and take a hack at it because that sucker is huge! Im going gk try and get it to like the acerbis evo fender, if I fail I'll prob buy that one. I didnt know if it would still be big since they are meant for 17" wheels.
 
#49 ·
A Narrative.

Hombres!

So I hadn't messed with the CR85 in months after buying that other engine and it giving me problems. But a couple weeks ago I went and did a top end again (a lot easier the second time around) and noticed that when I dropped in the OEM ring the gap was already at the max end of the service range. So I'm thinking this jug is going to need to be repleated soon. :(

Anyhow, after replacing the top end the bike came on in just two kicks but revved to the moon! Uncontrollably! The idle screw had no effect on the revs whatsoever; after that I switched her off and neglected her for a month.

Until recently when I was switching my Chonda's throttle over to 1/4 turn and after the switch it displayed the same symptoms. This time I knew it could only be the throttle, so I removed it, retraced my steps and fixed the issue. That got my thoughts going, maybe it can be the same with the CR and lone behold it was! Got the engine to kick on with two swift kicks adjusted the idle and she purred.

Today I don't have to go to work untill 12PM, and so I decided this is the time most adults are at work; I will give the bike a test run. Got the bike warmed and went to take off and as soon as I hit 1st it shut off. I pull the clutch in gave it a kick and notice the bike wanted to start moving with the clutch pulled in, so I look down and see the clutch adjustment is all the way at the bottom end, so I adjust it back into the middle range and got her going. She has enough power to move but maybe 1/8 in to the rpm range it doesn't put down power and just revs. At this point I'm rolling along and adjusting the clutch lever play and with some tweaking she came alive! Lofts the front coming out of first and second even with the smaller rear sprocket. I had forgotten why I had bought this bike! It flat out flies!

I must say it is extremely difficult to ride a 2t for me, how do you stay in a good power range while mid turn? I feel if I stay within its powerband while cornering with a small slip of the throttle the rear will drive from under me. Exciting! The 15 mins I spent trolling the neighborhood were a blast, until some 30-something year old low life came and ruined it because I was taking away from his sleep. It was 11:00am!

Blah! Is there a way of quieting down the bike or is that just the nature of the beast with a 2-stroke? And I noticed something, that I thought was odd but coming from a four stroke may not be. In the upper gears 5th and 6th I noticed it would pull to a point and then just rev but still continue to build speed just without that grunt from the lower gears [Hard to describe]. Is that cause of the gearing change I made in the rear or could it be the ring gap issue I mentioned before.

At any rate, I am so ready to get some track time! Now I just need to get ShortyR6 on his CR and line up our schedules! :anim_peep:

Sorry for the long read,

Diego
 
#53 ·
I'm going to chime in on the premix ratios. In my opinion, 32:1 isn't enough oil for an 85 that is zinging around at WOT on a kart track. 24:1 or 25:1 in my opinion is better. And yes, the 800 2T seems to be the "go to" oil. I use the double ester "ROAD" version, not the single ester MX oil. The jetting will have to be richened up slightly if you go with more oil.

I just split the cases on my 40-hour 105 bottom end. Everything looked perfect. The lower rod bearing was still tight and didn't have any signs of bluing or excessive heat when the crank was split.

This is at 24:1 with 800 and a 50/50 mix of C12/ Pump 93.

Too much oil never hurt a 2-stroke...
 
#55 ·
I talked to my motor guy and we are going to adjust our bike for the SM track.

he did say for our KTM65 the 800 2t road is the way to go for SM. we are going to up our mixture from 60:1 to 40:1, run a colder plug, and richen up the main.

for the CR he also said go a little richer than 32:1 and you may have to richen the main on there as well.

Toad, thanks for putting that out there, it caused me to get out of the MX mindset and do some R&D for a SM set up.
 
#59 ·
What I've Been Up To..



I decided to take on a rebuild! The OG engine was just sitting there collecting dust, so I decided to at least make it a learning experience. It will be getting a full rebuild, bottom end and top. Everything was smooth sailing for once with me :lol: the crank does not have any up and down play at all, should I just buy an OE crank or send this one out to Cooksey?

I'm going to replace the bearings since its already apart, and replace the waterpump seal as it was weeping before I took it apart. Since the top end was only giving me 85psi compression with a new piston/ring I'm going to go out on a limb and say the walls are beyond the service limit (this is the cylinder where the piston pictured on pg. 1 came out of). So I am going to supermini that bish through Eric Gorr and have the 102cc for fun and have the 85cc to race in the lite classes through 305-Motard.



And remember that caliper AR said wouldn't work with the older 450 caliper? Fibs! Oversized rotor coming in the mail! They should update the product description :D
 
#60 ·
I think I'd just buy an o.e. crank, they are only about $100-120, where a rebuild will cost you a little more than that. You could always shoot Andrew an e-mail and ask his opinion, he'll do right by you either way.

Before you commit to Gore, get in touch with Brent at http://www.tdc2strokeperformance.com/
He can build you a ripper of a supermini motor. He just did my cylinder and head, and he's another guy that is just a pleasure to deal with. He will want your whole bottom end to measure port timing and stuff, as the CRs have a lot of variation in deck heights and ports, etc. It will cost a little more but I think the end product will be far superior.
 
#63 ·
I priced out the Hotrods and Weisco kits and they were approx $160 and the OE was $170 those prices plus the shipping and truing would put me close to $190. If I am reading Andrews website correctly he included all of the above for $155! I'm definetly going to give him a shout before hand either way.

I've also seen TDC website before when looking into the big bore pricing, and they're out of my range; granted his work is more thorough but iirc the prices are upwards of $1k? I just see it as too much, I wont be doing any competition or anything with the bike to warrant that type of price. Remember I picked the bike up for $400! What an expensive hobby! :D

Just remember the more oil you are using, the more it leans out the bike. more oil means less gas. 32:1 motul 800 2t road should get the job done. if you go more oil, you will have to richen up the main.


as far as the crank goes, call cooksey. i dont even trust OEM cranks to be super straight. he will get it dialed in so that your bottom end will last a long time.

if you are wanting to do your top end yourself, send your cylinder and new piston to http://www.usnicom.com/ and they will get you right where you need to be on the top end.

Toad, I have read great things about Brent's work at TDC.
Good to know, if I follow correctly would going down on jetting help eliminate some of the sludge I'm getting out of the pipe? It ruining my plastics! Haha.

As far as the cylinder boring with US Chrome is that $262 the price! Cuz that would be sweet!

Diego
 
#61 ·
Just remember the more oil you are using, the more it leans out the bike. more oil means less gas. 32:1 motul 800 2t road should get the job done. if you go more oil, you will have to richen up the main.


as far as the crank goes, call cooksey. i dont even trust OEM cranks to be super straight. he will get it dialed in so that your bottom end will last a long time.

if you are wanting to do your top end yourself, send your cylinder and new piston to http://www.usnicom.com/ and they will get you right where you need to be on the top end.

Toad, I have read great things about Brent's work at TDC.
 
#68 · (Edited)
Small update, made a catch can, and got the 450 caliper and OS rotor on. Do you need to have the little metal clip in the carrier for your brakes to work? For some reason with the clip in the caliper wouldnt go on so I took it off and it worked. Didn't notice any reason why it wouldnt work, but I only rolled it and braked.



You guys running a seperate catch can for the radiator or just running a long hose ?

 
#69 ·
Are you talking about the bent piece that sits between the pads and the caliper? If so. that helps keep the pads separated when you remove the rotor and it keeps the pads from rattling around when you aren't braking. Other than that, there is no performance reason to either have it installed or not.

If you haven't bought a crank yet, you can find complete Wiseco kits on ebay for a good price.
 
#70 ·
Shazzam!



PSCook, this is the little clip I removed. Its not the one that goes in between the pads in the caliper, but rather the one that goes on the carrier itself. From what I've google its to keep the noise down, so I think I'm OK.



What are you guys doing for the suspension, aside from actually having it revalved and sprung. The front end dive on the MX suspension is CRAZZY! :lol:

I plan on raising the forks as high up in the triple tree and I'm going to turn the compression up to stiffen up the front as much as I can. Any suggestions from guys who have run the 85 in SM?
 
#71 ·


What are you guys doing for the suspension, aside from actually having it revalved and sprung. The front end dive on the MX suspension is CRAZZY! :lol:

I plan on raising the forks as high up in the triple tree and I'm going to turn the compression up to stiffen up the front as much as I can. Any suggestions from guys who have run the 85 in SM?
There isn't much you're going to be able to do with them without springs at least. A "cheap" way to make it halfway liveable is to throw some BBR fork springs in it with some heavy oil, and a BBR shock spring on the rear. The valving won't be right, but it will be 1,000 times better than what you have.
 
#77 ·
Niice. Too bad mine arent even broken in :/ I think I'm going to do the May date instead of going to PBIR with the SB just because its a lot cheaper. Did you get any video of you guys out there? I saw Cam was leading you around the track. Haha
 
#80 ·
Negative, I was able to get mine to hold.

I have some video. i was looking through it last night. its not that great, because the camera on my helmet was angled down a bit low, but there is some good footage of me chasing cam for several laps. i should have some time tonight to get it edited and posted to youtube.

on a side note, i should have my suspension in the mail tomorrow to fast bike industries. i cant wait to have something a little more solid under me.
Oh snap! Getting the suspension done already? How much that run you?
 
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