2 Stroke 1988 CR250R Wont start / Wet Plug

Redordead89

Redordead89

Shit man, been so busy with work and trying to get rid of England off the sole of our Scottish work boot I've been missing all this :doh:, great to see someone get stuck in to and old red rider!! :hifive:
Keep up the good work !!!!:thumb:
 
Stringer

Stringer

Redordead89:
Shit man, been so busy with work and trying to get rid of England off the sole of our Scottish work boot I've been missing all this :doh:, great to see someone get stuck in to and old red rider!! :hifive:
Keep up the good work !!!!:thumb:
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Thanks! It's a rewarding experience for sure.

Today my front brake caliper pistons came in! So I was able to rebuild the front caliper with new everything. Tomorrow I'll mount it up and bleed the brakes.
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I also saw a cool youtube video of a guy truing motocross wheels while they were still on bike with a spoke wrench and dry erase marker. I think I will give this a try tomorrow.

I decided not to use that hone because I was worried it would get caught on a port or something. If I run my fingernail across cylinder I only feel the tiniest bit of a scratch. What should I use on this, besides that spring loaded finger hone? Thanks!
 
Stringer

Stringer

Well shit. I get everything bolted up torqued perfectly but my front brakes are still dragging? When I installed the wheel and before I bled the brakes it did not drag. Now that I flushed everything, and bled the brakes they drag. I give the wheel a good shove and it only revolves about 2.25 times. The drag seems to be pretty uniform, as it's not snagging in just one area of the rotor. What does this tell you guys? Do I now need to rebuild the master cylinder? Or maybe it's something else? Perhaps worth noting, that it took awhile to bleed the brakes. Took a lot of repetition to get the lever to feel right and not way spongy :/

I did get my Evans waterless powersport coolant in the mail though today.
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2strokesteve89

2strokesteve89

PALMER84ONE:
Namura is junk, I would not use one. Just pulled the motor apart on a YZ with less than 10 hours and the cylinder needs a run down. Not my rebuild, the shitty shop called Inside Line Racing! Live and learn, have 17 hours on my first rebuild on my sons bike, no problems.
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I agree. Always used Wiseco but had a weak moment a couple years ago and went with the cheaper brand (it rhymes with Namura)
In half the time I change out the Wiseco piston this one breaks into pieces. Fortunately did not harm the cylinder.
 
Stringer

Stringer

Glad I went with pro-x! Got the kit for under $76 shipped. Pretty sure I wouldn't be saving much with namura.

Any ideas on these brakes? Thanks!
 
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2strokesteve89

2strokesteve89

If I'm getting this right, with the pads pushed back or the caliper off, the wheel spins freely, after a brake application it drags, but when you open the caliper bleeder it frees some but not 100% so I would say that the front caliper is still hanging up for one, since you isolated it from the rest of the hydraulic system by opening the bleeder and while improved still had a problem, I would start at the caliper first, recheck all the rebuild, was there any issues with the caliper housing, pitted bore? The caliper piston seal serves to purposes, one to seal fluid under pressure and keep foreign materials out. But also it will when pressure released pull the piston back just slightly as to keep the pads from riding on rotor and causing rapid pad wear, so if the seal isn't functioning properly your problem could lie there. If your confident the problem isn't with the caliper after rechecking, then go after the master cylinder.
 
Stringer

Stringer

All the pistons and seals are new, and bore looked good. One thing I do remember seeing, is the brake pad pin had 2 worn areas on it. Could this be it?

My original front caliper I messed it up bad. I couldn't get the pistons out so im drilling at it, and when I finally get them out I see that I messed up the bore. This caliper is a used one from eBay that is in better shape than the other one, before I drilled it lol. I looked at the other brake pad pin since I had two, and they both have wear marks. So im not sure if this is it or not.

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Stringer

Stringer

SRAD97750:
If the brake pad rides in the worn area, that could be causing the pad binding. -BIG DAN:thumb:
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Mihylo33:
I agree with this statement.
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Ok thanks! I will order a new brake pad pin tonight. Looking back, I should of just bought the caliper rebuild kit instead of buying the OEM seals individually. I didn't realize the kit came with a new pin which wears a lot. Well I still needed the pistons too. And a replacement caliper. lol.

I found a pro-x front master cylinder rebuild kit for 17.99 so I just got it to be on the safe side. I haven't yet looked, but I hope the install is pretty straight forward.

I noticed also that my rotor is not perfectly straight. I was able to correct it some with some channel locks and a shop rag. Still not perfect for sure. It still catches a bit in certain areas. I find it real hard to get it perfectly straight, though I may employ other tactics. This lead me to price out a new one. Wow expensive! The MSR's go for 125, the Moose Racing MXR's go for 100, and the absolute cheapest ones from china go for 40. I was able to find a new Moose Racing MXR Blade rotor at dennis kirk on closeout for $27.50! I got the last one. I figure if Im able to straighten my existing rotor out better, I can sell it on Ebay for like 80 something bucks. Or I can use this badass mf new rotor I got on the ultra cheap! A perfect compliment to new pads, pistons, seals, master cylinder parts, and brake pin. If this doesn't fix the front brakes I don't know what will! All that would be left is the brake line ...
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Today hasn't been a total loss as my red silicone hose kit for my Honda, and moose racing 25mm hose protector came in. Did I say hose kit for my Honda? I meant hose kif for my Handa.
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I don't see 1988 listed but if they spell like that, how much can I believe from chinaman anyway?
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But for $32.60 shipped to the house. I'll roll the dice.

Hose protector looks nice. I figure it would be way better than the zip tied, ragged heat wrap that was on there.
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About this eBay cylinder I got, I get an oh so very slight fingernail snag towards the bottom. Very small. Should I do something about this? I don't want to use the spring loaded hone I borrowed, I read it can easily snag a port a screw things up. Especially since I have no experience. Should I take the cylinder somewhere for a quick hone, buy a hone, hit it with steel wool, do nothing? What do you think? Thanks!
 
SRAD97750

SRAD97750

Moderator
Staff member
Stringer:
I noticed also that my rotor is not perfectly straight. I was able to correct it some with some channel locks and a shop rag. Still not perfect for sure. It still catches a bit in certain areas.
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I wouldn't try to bend a rotor. That would be a replacement for me.
Stringer:
About this eBay cylinder I got, I get an oh so very slight fingernail snag towards the bottom. Very small. Should I do something about this? I don't want to use the spring loaded hone I borrowed, I read it can easily snag a port a screw things up. Especially since I have no experience. Should I take the cylinder somewhere for a quick hone, buy a hone, hit it with steel wool, do nothing? What do you think? Thanks!
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Depends on how far down the cylinder the nick is. The piston rings only come just past the lowest port. If it's below that area, you're fine.

If you were to hone a cylinder...
These hones are straight forward. You make sure not to let it fall into a port while turning. Gives you more than a couple inches of stroke, which is more than enough to crosshatch a cylinder.
I use my table mounted drill press set to the slowest speed (180 RPM), and set the depth so that the hone doesn't hit the bucket the cylinder is sitting in. In my experience, hitting the bucket is much more violent than falling into a port momentarily. :smirk:
Be sure to provide oil or transmission fluid regularly directly to the hone blades. Keep the up and down movement slow and smooth. If it starts hollering or screaming, you need more lube! You'll find a sweet balance of oil application to keep the hone quiet and still really start cutting into the bore. I think a oil gun squirt every 3-6 seconds was about right. You'll see the black steel particles collecting around the top of the cylinder in the excess oil. I use this as a gauge for how deep I'm cutting.
Don't be afraid, on the stiffest setting, these hones can take maybe .001" per 30 minutes of honing at that speed. It's just for removing light scratches and whatnot.
-BIG DAN:thumb:
 
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