DAMN Riders - No rules, Just ride!

When I bought the RL a few years back, it came in really good shape. I mean for a almost 40 year old bike, it had all original parts and paint and looks great. The seller got it from his grand pa and it was ridden around on the farm. Never really used it for real trials events or stuff, so only one small ding on the tank and the frame and such look really good. The seller said the top end was original and needed to be replaced and he had a bag with NOS piston, rings and all gaskets! Well it's time to do it. While the motor will start and run fine, it lacks power from the rings being tired.

SO this weekend I decided to start the job. It's an easy job to do and doesn't take long, but I figured I would take my time and post some pics of the process along the way for those who maybe haven't ever done a top end. Granted, it is a simple 70's 2stroke, so no power valve or such to deal with.

SO I'll take some pics along the way and post up the process for those that may be interested.

Chop - chop....lets get some pics rollin

Boom Boom wrote:Chop - chop....lets get some pics rollin

+1. I'm likely going to have to do my Montesa too.

Okay, so the first thing is to check you have everything. I have the Piston, head gasket, base gasket, wrist pins. I have all of the tools except, the box end attachments for the torque wrench for the cylinder. I can take it down, but I need to go buy the adapter so I can torque the cylinder properly. I picked up some 200 and 150 grit sand paper so I can sand the head base. Older motors can get some slight head warpage so it is always a good idea to lay the paper on a flat surface and do a head sand in a orbital figure 8 kinda pattern to ensure the surface it clean and level. I'll use some WD40 and a wire brush to clean out the exhaust port once I get the jug off. Hopefully the cylinder is in good shape with no need for any work there than just a good cleaning. The piston and rings I have are STD, verified by the part numbers on the boxes they came in, so if there is any excessive wear on the cylinder, I'll have to either re-sleeve it or go to a bigger piston and rings. SInce I have these NOS parts, I would probably send the cylinder off and get it re-sleeved to stock specs. The sleeves are steel with no special coatings, so easy to get that done.

SInce I plan to do this work in the "Formal Bike Display Room", I put down some thick cardboard from a bike crate I had saved. Nice 3 feet wide by 7 feet long, so great for this kind of a job. I went ahead and removed the gas tank and carburetor and throttle housing from the bars before I took the bike into the house. Part of this job is replacing the stock wide old school handlebars with some new aluminum bars for a better feel and control. I already have added new cables and levers previously. The stock bars are seriously wide like beach cruiser bars. Really hard to ride around trees and such, so they gotta go!

I figure while I have it up on the stand, I'll polished the rims, cases some and clean the motor up a little. The motor looks good but the cases have a little spidering on them that will buff right out. Frame paint as well as tank paint looks really good for a 40 year old bike, so if I clean up the rims some and the engine cases, this is gonna pop! I re-painted the front fender and it looks good and the rear fender is a NOS the previous owner had added, so even the plastic looks really good.

I plan to start tearing down the motor this week in the evenings and then I'll start the pics of the process. If I get lucky, this thing will be up and ready to ride by the weekend else, it might be a 2-3 week job if the cylinder needs work.

Are you doing this work in your "living room"?

BillyGoat wrote:Are you doing this work in your "living room"?

No, not the living room, but there is a formal dining room adjacent to the living room and I am setting it up in there. I don't use the dining room as the kitchen is huge so my dining table and chairs are in there.

Okay, so I got off my ass today and got started! I actually have plenty of room in the garage to work on it, so not gonna move it into the house.

Position the bike and take the tank off, pipe and the seat. Ready to tear down the motor!


Tank only has 2 small dents and the paint looks great!


I told ya the stock bars are mega wide!


Head ready to come off. I sprayed some WD40 onto the head bolts to let it sit for a while just in case.


Plenty of room to work once the tank is off. Still gotta pull the carb off.


Okay, that's it for tonight. Getting hungry! Next is just remove the carb and then the head. Once you get to this point, have your clean rags ready, cause as soon as you pop the head and then remove the jug, you want to close off the cases to ANYTHING that could fall in there by the crank, that's no bueno!

Okay, dinner over and anticipation kicked in! WANT TO SEE BARREL!
Disassembly was "No drama" and easy peasy. 6 head nuts and 4 cylinder nuts. Everything looks REALLY GOOD! Hardly any carbon buildup in the head, the ports and the exhaust exit! Some on top of the piston, but nothing too thick or non-normal looking! This thing is low hours with out a doubt.

Barrel looks pretty good. No real markings or anything to the touch. I'm gonna take the cylinder and head to get media blasted I think and have the barrel honed. Still need to measure it, but it looks like all it would need is a piston and rings. Hell the stock piston still looks good actually.

All that is left is to clean it up and re-build. Easy job, maybe an hour total to get it all down and that is cruising and taking my time.

I just dropped the cylinder/head off to my buddy at work and he is gonna media blast it today and get her all cleaned up. I then decided to just order a honing brush from Rocky Mountain since they are 40 bucks and it would have cost me that probably to have a machine shop do it. I'll get it thursday, so should have it back together by this weekend. Just drop the honing "brush" in the drill and use some WD40 and run the honing brush up and down the cylinder till she is all clean and cross hatched, then ready to go!

The cylinder looks really good. No real excessive wear spots, clean to the touch and looks fantastic.

Tonight I am gonna swap the handlebars out while waiting for the parts to finish up the cylinder. I also ordered a can of Permatex Gasket Prep/spray. It is a copper based spray for gaskets to coat them, fill in small imperfections and make the seal perfect between the cases and the cylinder. 6 bucks for some piece of mind. It is heat resistant as well. Head gasket is a copper gasket, so it gets no kind of prep other than a good clean surface on the head and cylinder, which the media blast should create! I will still run the head around on some sand paper to ensure nice and level prior to re-assembly.

Lastly I ordered the new petcock for the tank. Mine is the original and was leaky, so NOS one for 30 bucks.

When I am done, this bike will be ready to go for many many seasons of riding. These old 2 stroke motors are so simple to maintain and fun to work on!