Triad

Found the seals, got both the pullers and managed to take out both the flywheel and the cush drive on my test-engine (Explorer, partially seized). I'll do the same on the good engine as soon as possible.

Thanks for the picture! I understand what the split spanner and the bigger "bushing" are for... but what about the smaller/taller one? What about a bearing puller like this one? https://www.amazon.it/VEVOR-Estrazione-Cuscinetti-Separatore-Autoveicoli/dp/B0FNNLQKQG/ref=sr_1_32?__mk_it_IT=ÅMÅŽÕÑ&crid=1J9OT632AEQI4&dib=eyJ2IjoiMSJ9.F7DabM4KgRoeLNC5m87AKWI_81P6lH4H-JJv9hmS54VsgH7Jl2H_sBto6YefSEh2Mr323F-rM-F6YW7kURCX9k4AS5nS0TQq7oseyI-y_6tyoIFOlLERt7evmcUJ3FppwkGGwQj942Cg5GP412S4qc2SW3V26VtVvBueYD8eTEv9qbVyeMNwz6EW76d88atoDXLtvB6dwI508tvq0yavbEFXIFUbUhArl26l9Kup6xcINWcCpPb23ntBHz3ppRigPMkKMroC5-emTMg1sGRRxL5fJcUrS9xzKy0T9G8Bdr0.Ij-6NlEcHc2accfls-XnAXjYLpCaYct6YzIU-jgxHC0&dib_tag=se&keywords=estrattore+cuscinetti&qid=1766358853&sprefix=estrattore+cuscinett%2Caps%2C315&sr=8-32 I think the flywheel needs a puller M27x1.25, right? I can easily find one locally. Do you remember the measurements of the seals, by chance?

I guess they do, but they probably already have the puller? Is it absolutely impossible to get the cush drive out with a standard 3 arms puller?

Didn't really find it with my google search... I'm in Italy, BTW. I tried to find a mechanic willing to do it... some say they won't open the engine unless it's for a total check of all the parts. Another guy asked for €200, not sure how long it takes but seems a bit on the steep side, maybe? I should also take the engine out and pack it to ship it to his shop (and of course have it picked up after the job).

Uhm... gotta say the videos of guys pulling the cush drive with a handmade puller didn't really make me think it was easy. I tried to get in touch with a few mechanics here, specialized in old enduro bikes, but for now still no luck. Not really too excited at the idea of doing it myself, this bike is definitely way different from what I usually wrench on...

Hello guys, sorry to resurrect an ancient thread... I have an Ossa engine requiring new crank seals as it's drinking gearbox oil. I'm kinda skeptical about doing the job myself as I never worked on such an old bike and I don't have the pullers. Is it hard? What kind of pullers do I need? The engine should be from a late 70s Pioneer, has the coarse teeth levers and runs, so the Motoplat rotor is good and has good compression. I'm in Italy, can't find a shop willing to tackle the job for me.

Sorry to resurrect a 6 years old topic but... was it the model with or without the "powerjet"? I just fitted one of the chinese PWK clones on my 250 Pioneer engine with Explorer exhaust... the stock jetting seems to be too lean (38 idle jet, 120 main). I just replaced the idle with a 45 as the bike tends to die even with the air mixture screw totally closed. Not sure the 120 main is big enough, we'll see.

Don't know how to "repair" the gear lever. I could drill a hole thru and use a passing bolt, maybe, covered with a piece of hose for the time being? Or I could use two metal clamps to keep an L shaped piece attached on it?

Thanks... makes perfectly sense. I don't think I'll be on the hunt for a Pioneer exhaust, it would probably make more power up top but I plan to use it for "semi-trial" stuff at low speed, so it's probably better to keep the Explorer exhaust with the smaller carb. I guess the cylinders are also different on the inside (bigger intake/exhaust ports)? I never worked on Amal carbs, so don't have any jet for it... hopefully the stock setting will work with the actual setup.

Ok guys, managed to find a Motoplat coil and the right kickstarter lever for this engine. Also got a tank with petcock, but they're both pretty much trash. I poured some pretty rich premix inside the spark plug hole and the engine came to life, with huuuuge surprise. Started but died after 1 second. The second time I started it, lasted maybe 2 seconds. In the meantime I tried to put the tank in place with a hose going to the carb, but ended up badly with my cursing and fuel everywhere. Today it started at first kick (!) and for maybe 8 seconds... I managed to twist the throttle a couple of times before the fuel into the bowl finished and it died... but it's aliiiive! As you can see the carb is the Amal from the Explorer engine... should I get something more modern and better for the Pioneer engine? I read it had a 32mm. The guy I got coil, kickstarter lever and tank from, kindly sent me for free a rear brake cable and a broken gear lever (I'll have to find a way to make it work).

This is the engine fitted, the exhaust and carb in place. I found a guy who's got a MAR 350 partially broken in parts in his garage but doesn't seem happy to sell the kickstart lever etc. without the whole engine block. 🤨 I still need the kickstart lever and the 2pins Motoplat coilpack to try to start it... from there I'd at least know for sure the engine works and could start looking for a better clutch cable, rear brake cable, silencer etc.

I guess no "modern" bike has a similar lever? The fact it's on the left side makes things harder anyway.

Hei guys, got some good news for a change... Checked and the intake diameter is 36mm like on the other engine, so I was able to fit the carb manifold to the cylinder. Also found out the cylinder will take the Explorer exhaust, the flange is removable and in its place I fitted the Explorer header. So thankfully won't have to look for different exhaust/carb. Have found a guy breaking a MAR 350, so I should be able to get an original Motoplat coilpack... but can't say if the kickstarter lever will fit.

Thanks, if the "stator" is broken I think I'll simply abort the project and will try to cut my losses... found a guy here in Italy who's breaking an Ossa MAR 350 but don't know the production year... was the MAR still around when they changed the teeth of the levers on the engine block?

Today I was away so couldn't check the gear lever and the exhaust compatibility... will try to do it in the weekend. Hopefully I'll find a solution for both