General tips needed
 

So I bought a 2005 Roketa DB-27a the other day, top end already removed.

I'm going to buy a full gasket set, piston rings, and valve assemblies. Is there anything else I need to look for while its disassembled?

The only reason I'm buying the valve assemblies is when I got it, one of the valve springs were missing. I can't find anywhere to buy just the springs, so I'm just buying the whole set.

Everything else looks really good, the bore looks good(haven't had a chance to measure it yet), still can clearly see the cross-hatch on it. Piston looks good, timing chain looks good, as does cam. Of course, I'll check measurements to know for sure.

Other than that, the body looks good, suspension is good. Haven't checked to make sure but I believe the previous owner removed the switch for the electric start, which doesn't really bother me.

Any good resources for these bikes? Good places here in the states to buy parts?

EDIT: What bikes are parts interchangable for this one? I've heard XR200R's are the same?

The XR200R is similar, but not the same. The bore and stroke is different, as is the top end. Clutches, gears etc are probably all the same.

Not sure where to buy parts like valve springs in the States, so hopefully someone else will chime in.

Correct me if I'm wrong, but if I don't mind kicking, I can remove the starter, and battery completely can't I? The bike has no lights

That's a very timely question; I just posted something similar today:

If you have an AC version (if you can start it without a battery, that is a good indicator), then yes, you can run without the starter also. You'd need to figure out how to plug the starter hole.

I have a '96 XR250R, and I really wish it had electric start.

Thanks for the info, I guess I'll leave it on. No point in ripping things out that may make the bike not work when I'm not sure it will work in the first place, lol.

I have a shop manual from a XR 200 I found online, looking through their crude pictures, it looks exactly like the Roketa.

Any idea where I can find some specs on the roketa engine so I can check clearances and such? I know the bore * stroke is different, mainly using the manual to make sure of the parts/position of parts.

Its a completely different beast putting this thing together when I didn't take it apart!

If your Roketa is OHC, then the top end will be the same as an XR200R; I was thinking of the OHV pushrod version. The bottom end on the left side will be different because of the starter.

If you provide us with the number that is stamped on the engine, we can try to decode it, although they're not always 100% accurate. Look for something like 63fml.

I think I remember someone uses xr valve springs. Where are the pictures.

Just use photobucket.com to upload them.

Ill get some pictures up tonight or tomorrow. Tonight if I can find one of my digital cameras, tomorrow if I have to use my phone( no flash).

I'd just about swear xr springs will work. Other than the bore ad stroke the manual seems identical to the roketa. Ill also get the engine number in a bit.

I'm excited to get this thing running. Last bike I had was a 80s model Suzuki dr100 I pulled out from under scrap at a friends barn. He said it had been sitting in the weeds for 10+ years and I could have it for free. A little tinkering and got it running. I think after it was all done I had $15 plus gas in it. Ran it hard till it died. Clutch would stick if you used it so had to just rev it up and drop it in gear and hardshift it. Of course sprockets were almost smooth, had a bad oil leak. But ran like a champ until my friend borrowed it and didn't put oil in it. Siezed the motor good, lol.

This bike I plan on making nice and keeping it that way! But hell, the gas tank on the Dr was just a 5 gallon gas tank strapped to the frame and a petcock tapped into it. Couldn't take that thing to serious!

EDIT: Alright, pictures are up, took pictures of everything as it sits right now.

See them here: https://picasaweb.google.com/1042146...at=directlink:

Couldn't find a number stamped on the engine anywhere. How long is the number and where is it located?

Looks like like an OHC motor to me. I believe that xr springs and parts will work.

The smaller valve is the intake, correct?

Seems I'm missing the wrist pin too. Looks like it would be easier to get a top end rebuild kit.

Anyone have ideas where to find one for this motor? I'd hate to get one for a xr seeing as I wouldn't be able to use the piston or rings.

Another question, I know these bikes aren't built that well. I"m going to replace bolts all over the place, loctite everything, and gorilla glue it for good measure.

What can I do to make it more withstanding? Beef up any welds? Add any braces? I don't go jump triples or anything. Just fields and woods for me. I think the worst "jump" I have where I ride the most is where the field slopes down at the top of the hill, usually get air for about 5-10 feet and drop maybe 2-3 feet. Nothing hard at all.

Occassionally I go to a friends track where there are slightly more harsh jumps, but still nothing worse than a 5' single that if hit right you'll land on a 5 foot decline on the other side, with no more than 2-3 feet of air.

I'd be more than happy to stay away from my friends house with this bike if it just won't handle it.

It looks like there is a smooth section under the shifter that might contain the engine number. If you can measure the wristpin hole diameter, I'll see if I have a spare that matches. Measure your remaining spring as well; give me the free height, ID and OD and I'll see about a match for that as well. What is the true diameter of the piston?

https://lh4.googleusercontent.com/-Y...0/DSCF4838.JPG

Stay away from the track.

Alright, here we go.

The wrist pin is there so no worries. Although it is missing a circlip! Why couldn't the guy keep all the little pieces, lol.

Tell me if these measurements sound way off, without my tools here(conveniently, my friend is on vacation, and my stuff is locked in his building!), I'm having to make due with what IS here.

Spring Height: 1.734", OR 44.04mm
OD:1", 25.4mm
ID:.734", 18.64mm

Piston actual diameter:2.671", 67.84mm
Cylinder Diameter: 2.703", 68.66mm (it is in complete round)

Ok, I dismantled an old XR200R head, and my measurements are pretty close to yours.

Mine is 45mm vs your 44.04
Mine has an OD of 26.6mm, vs your 25.4
mine has an ID of 18.8mm, vs your 18.64.

There is also an inner spring, and it is 39mm long with an OD of 17.65mm and an ID of 12.3mm. There is also a steel shim under each spring to prevent galling at the spring seat.

My spare piston is a 66.5mm. Too small for you.

It looks like an XR spring would do the trick. I can also spare a circlip. Do you want me to send this stuff to you? If so, send me a PM with your address. BTW, the small valve is the exhaust.

You are a godsend. I was having trouble justifying buying all new valves just for the springs. The springs on it look almost new. Going to check the piston rings tomorrow, the guy I bought them from said he thought that was the problem but while cleaning te engine up today I found some bad connections in the harness that goes to the cdi
I think that just may be the culprit.

Also noticed its missing the front brake line from the handle. Time to hunt that down!

Aww, shucks. :D

Regarding the bolts for the head, those will be very specific and not likely easily found at a hardware store. Try to estimate the length of the bolts you need, and I'll compare that with my bolts. Migfht as well ship it all at once.

What do you mean by front brake line? Do you mean the hose?

The brake hose that comes out of the master cylinder on the handle bars.

The bolts are all of these on the website.

http://www.roketapartsdept.com/catal...RTS-415-1.html

I'm pretty sure I have them, especially all of the ones from the engine. Its the frame mounts that I'm not positive on.

Ok, that won't be too hard to find locally. Perhaps you could even drill out the mounts and use grade 5 SAE bolts.

The best bet would be to buy a complete front brake assembly; it'll be cheap on eBay.

Yeah. I'm going to look around. Until then, I rarely use the front brake anyway :twisted:

I just sent a front brake line off yesterday along with the caliper. I will send him a message and if he doesn't need it maybe he can send it to you.

Allen

I think I just might have found the most helpful community around!

That would be quite kind of you, and possibly the second person as well. I knew picking up a 6 year old china bike would be interesting to get parts, but you all are downright spoiling me!

He will let me know if he doesn't need the line.

Just out of curiosity, why did the original owner tear it down? Was it burning oil or just not starting?

Not sure. Guy I bought it from got it as a project. He sold it because he had quite a few projects going.

That's why as I'm putting it together I'm making sure everything is in good working order. If I know its mechanically sound ill know to dig into the wiring and electrical.

Checked the piston rings tonight, can't fit the smallest feeler between the ring and bottom edge. Rings still turn easily around the piston though.

As for the opening, it is at the upper end of the spectrum, .406 and .457 for the top and middle rings, didn't check the oil rings but they are right in line with the previous.

Does this seem alright, or better get new rings?

When you say the opening, do you mean the ring gap? Are you measuring it with the ring in the bore and not mounted on the piston?

Yes ring gap and yes in the bore without the piston

According to my Clymer Honda manual that covers '84 and '85 XR200R models, the ring end gap on the top and second rings should be between 0.10 and 0.30mm. The oil ring spec is 0.2-0.7. Yeah, I'd get new rings.

BTW, the side clearance is listed as 0.015-0.045mm for the top and second ring.

When I rebuilt an XR200R recently, I used a master cylinder hone for the bore. I think I bought a Lisle (vs the generic Chinese model) because the stones are replaceable. I also found a small piston ring compressor for cheap. I hate breaking rings.

New rings are ordered. I have a hone and ring compressor to use so no worries there.

I wish I knew what the problem was but since I don't on checking everything. Except the bottom end which Im not going to tear into until I get the top end rebuilt. Atleast then if its not operational I can diagnose the problem.

My theory is that it wouldn't run because of something simple, and the engine was dismantled. A little troubleshooting might have saved a lot of time for the previous owner.

It is to your benefit, because you have the skills to rebuild it, and you scored it cheap. :D

I'm struggling to get the large spring shim out of the spring pocket. :lol: There is very little room, and the oil film is acting like adhesive. I'll figure that out today and mail it off to you.

BTW, now is an excellent time to install new valve stem seals. You'd hate to find that it burns blue after all of this work. I'd buy OTC Honda stuff.

Yeah sounds smart. Ill have to do that. Will buy them tomorrow

I mailed the parts to you today; I expect that they should arrive in a little over a week.

Did you mail them from us or Canada?

Canada. They assured me that packages are unaffected by the postal strike, and it saved me some time.

EDIT: Glad you could save some time, :). I see you aren't far from the border but I've never been out of the US so I have no idea how bad crossing the border can be, but imagine its not something you want to frequent doing, lol.

While waiting for parts to come in, decided to paint the plastics, I know it probably won't last great, but then again, I don't plan on thrashing it too bad either, so you never know.

Here's some pics of the progress:
BEFORE:

https://lh3.googleusercontent.com/-O...0/DSCF4833.JPG

AFTER:
https://lh4.googleusercontent.com/-I...2/DSCF4865.JPG

https://lh4.googleusercontent.com/-0...6/DSCF4864.JPG

https://lh5.googleusercontent.com/-5...Q/DSCF4866.JPG

https://lh4.googleusercontent.com/-u...2/DSCF4867.JPG

The color appears lighter in the pictures than it really is, but not by too much.

I still have touching up to do on the stripes, thinking about outlining them in black pinstriping. Then the rear side pieces and the fork covers. Side pieces will probably incorporate more yellow and the fork covers will probably be solid as I expect they will get pretty f*$ked up. One is cracked all to hell so I'm gonna try and epoxy it for a cheap repair.

I recommend that you get that plastic off of the light fixture, before Mrs. Influencer88 sees that! :lol:

What kind of paint did you use?

Didn't have anything to hold them up with, and didn't want to picture my hand that is currently blue, lol.

Painted them with the Krylon Fusion. I'm very pleased with the paint, I've read where others say it doesn't stick for shit, but it does have a very long curing time(7 days) so if they try to scratch test before them, results probably will be poor.

After a day in 98F weather, they have cured pretty good, wouldn't ride through trails with them, but they are solid.

I cleaned the plastics with degreaser, scuffed them up with 800 grit, shot a ghost coat, waited about 15 minutes, applied another coat, 15 minutes, another coat, 1 hour, another coat, 2 hours, wet sanded, dried, shot another coat.

Tomorrow I'm going to wet sand again up to 2000 grit, then let it sit for the remainder of the curing time, then give it a few coats of clear, wet sanding in between, then polish.

Plastics are very smooth now too, :).

Spud raves about Fusion. I haven't tried it yet, but I'm gonna.

I appreciate the effort it takes to wet sand up to 2000 grit. Nice work.