ETZ 250 Barrel Removal

[nice2day]

Hi Chaps... I have another problem on my ETZ 250 probably because it must have been left outside for at least 20 years...not as the seller said...."recently removed from the shed"

I cannot remove the cylinder barrel. I have soaked the studs in penetrating oil all around their length. I have tapped under the barrel port and carb manifold upwards but the seal against the crankcase mouth remains unbroken. My next move is to try to remove the studs by unscrewing them out (not sure if this is possible either as these might be welded in by corrosion!) I just wanted to know if anyone else has had this problem or they managed to free it without severe damage being caused. Just knowing that other owners have had this problem makes me feel better..... ...Many thanks...Les

PS will send in some photos soon when I tackle chopping the swinging arm spindle to aid its removal...or should I say: attempted removal....


les

[Puffs]

If it's stuck on the gasket, removing the studs won't really help, I'd guess.

Yes, there can be a bit of sticking on the base gasket, that normally get fused to either side due to the high pressure & temperature. But I've never had much problems with that, as the gasket material isn't very strong. Try hitting it from the side, in the length direction of the fins; there should be several mm of clearance on the studs. Make sure not to damage anything.

[nice2day]

Hello Puffs. Once again thanks for replying to my request for help. I've just come in from working on the bike all day...Main job was to get that swinging arm spindle out...success and story to follow with a few photos later .. Then I turned my attention back to getting the barrel removed. Using more penetrating oil and a rubber hammer I tapped away and also found a convenient lever position at the front and top of the crankcase where the through bolt goes through. This allows safe levering (only light pressure used) to the underside of the front of the barrel. There was some lifting movement at the front but the rear did not want to move. After removing the rear stud (RHS), the barrel freed up and I could lift it off in the normal way. So the problem was the corrosion of the studs within the holes of the barrel....Unfortunately I am now tempted to fully strip the low mileage engine just to get the crankcases clean (aquablasting) The bike has done only 8K miles, but as I'm fully refurbishing the entire bike with new paint etc. I don't think I could fit a corroded dirty engine back into it....

Thanks again Puffs..Les

[Puffs]

That's all good news Les! So apparently there was less clearance on the studs than I thought.
Sounds like this bike has seen quite a bit of moisture then. What does the barrel look like, and the rings; any signs of corrosion? If you find corrosion there too you can bet your bottom dollar it'll also be on the big end & main bearings. If that is so, they are likely to fail when being used for a while, so that would be a good reason to take the engine apart. But if it all still looks fine on the inside, I'd just use more conventional means to clean the cases, and not open the engine up. After just 8k miles, wear should be very little.

On the other hand, opening the engine is not all that difficult, certainly not if you already have it on the workbench. But it will take extra time, quite a bit of it. And extra money.

Actually, 8k miles sounds very little for any ETZ 250, which must be more than 30 years old. Do you know anything about the history of that bike that would explain it? Does it agree with the other signs (like wear in the barrel/piston/brakes, still original Pneumant tires, ...)?

[nice2day]

Good morning Puffs. Regarding the very low mileage...I am confident this is correct. The evidence of everything I have stripped does bare this out. There is virtually no wear showing anywhere on anything. The bore and piston are absolutely pristine ( I know they last well) and fortunately the crankcase mouth and flywheels look perfectly clean. Carb slide is virtually unmarked etc. etc. so I do think the mileage is correct. The trouble is that the bike must have been ridden on wet and salty roads without ever cleaning it and also stored in a very damp shed or even outside uncovered. It was last used only five years after being bought new....about 25 years left standing... Tyres however, are new but look unworn.

I have stripped down a 301 engine before to replace the gear-lever return spring . The bike was bought new by me ( I still have it) . To be honest I cannot remember much about doing it only that I took a long time making an engine splitter plate and then after heating the cases in an oven realised it would have come apart quite easily with out it...I was hoping that this restoration would allow me to fit back the original untouched engine but the corrosion and stains would spoil the look of the investment in time and effort and money I am undertaking.

As regards the strip down...I was wondering how well the main bearings of the 1988 versions lasted? I am quite happy to buy high quality new ones but would rather leave the old ones in situ if they can be trusted to last...What's your view on this Puffs please?


Les

[Blurredman]

Are you able to place clean, flat, but strong piece of wood through the barrel. IE---- through the exhaust port and connecting to the inlet? If so, you could use the piston to help the barrel come off by using the kickstart and the said piece of wood?

[nice2day]

Hi Blurredman...Thanks for the suggestion but I'm very happy to say (and relieved) that I have removed the barrel now (see my last but one message). As for bridging the inlet port to the exhaust...I think the piston would get in the way but you could try bridging the transfer ports in some way if your method was tried...Much obliged....Les

[Blurredman]

Aha, sorry..


As for your engine re-build, you may or may not have seen my recent thread- although there are very few pictures.. It had all original bearings in it at 42k miles. BUT... The engine is soooo quiet now with all bearings replaced. Up to you, check for play and wear. 8K isn't much, and you're not likely to do 30 odd k miles within 5 years...... are you??

All SKF/Kyoto bearings for £35... Just pick individual from on-line.

PICS!

[Puffs]

On the "I was wondering how well the main bearings of the 1988 versions lasted?": I don't really know. If they have any corrosion, they won't last long at all. Pitting caused by corrosion loads the edge of the pit high, which then fails, and then the bit next to it, and so on. I've had a bike with bearings fail like that, and that taught me to replace bearings if they have any sign of corrosion, or even a hint thereof.

But yours doesn't. Without corrosion, the original bearings will 'last a long time'. Blurredman's 42k miles sounds quite plausible. Also depends on lubrication & how heavily they are loaded (an engine used for racing lasts less long). Honestly, with 8k miles I'd just leave it, and clean the cases in another way. Or spray them?