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a bit of Dnepr MT rebuilding


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Let me start by short intro.. So i'm a 21 yo dude from eastern finland, like 15 miles from the border of the homeland of these magnificent pieces of metal. I'm a truck mechanic, and i've been hangin around/wrenched all kinds of engines for pretty much all my life

 

In summer 2012 i kinda came across this dnepr by accident, i was supposed to pick up a bsa but it was quite f'd up, it had sporty front&wheels, hardtail, and no engine. Or there was, i na moldy box, pieces of 350cc and 500cc mixed together, but not enough bits to build either one complete. So i decided to skip that, the mods were very badly done and the laws on frame mods is pretty tight here..

 

So i heard someone say something about these shaft driven german boxers, and by snooping around there was this dirt cheap rebuilt dnepr mt-10. Well off i went to check it out, wasn't too far from me. It was pretty roughly done and had sat for 5 years. But i liked how the owner was honest about it being a piece of... Too light layers off a rattle can, and a bonus surprise in the rebuilt engine; he forgot to tighten the connection rods, and poo happened when he fired it up for the first time

 

It came with another engine, which did not spin, and he had no idea when was the last time it's been actually ridden. This is how it came to me, except that i had put on the new engine and changed oils and put some wires right:

dnepr%2520ulkona.jpg

 

But as you can see the rims and pipes were new, and front pumps, carbs, alternator etc. The problem with the stuck replacement engine was just that the piston rings were rusted to the cylinder, i renewed them, washed piston, honed the cylinder a bit and flushed the engine and put some new oil. Also he gave me an electronic ignition pack, so i put that in, and it fired right up. I rode it for a like 1 week, then i decided to put new rings to the other piston and clean that side too, and i'm not quite yet sure how i ended up doing this:

py%25C3%25A4r%25C3%25A4%2520ilman%2520py%25C3%25A4r%25C3%25A4%25C3%25A4.jpg

IMGP1538.JPG

 

Hope you approve of the thread! More coming soon, i got a LOT of project pics

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Allright, here goes then. When i got the bike stripped to that point, i decided to check the renovated engine which had the con rods gone wild. After all, the previous owner told me it had new crankshaft, camshaft, oil pump and timing gear set, and i felt like the engine i rode on was a ticking bomb since i had no idea how it was inside.

 

Here's the engine he had rebuilt 5 years ago, as you can see i have already started taking it apart to see how it's doing. The piston in the pic has a small bit missing, the cylinders were bad and valves cracked, and the left hand rod (right in the pic) had snapped and the piston was in pieces, i couldn't find it in the engine :ohmy: :

kone%2520p%25C3%25B6yd%25C3%25A4ll%25C3%25A4.jpg

 

But, when i opened the oil sump, i found the other piston:

%25C3%25B6ljypotti.jpg

 

Here we have some parts. You can see the piece missing from the piston, and that the camshaft fortunately seems fine. Also if you look carefully you can see the con rod slightly twisted downwards in the block:

m%25C3%25A4nt%25C3%25A4%252C%2520nokka.jpg

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So the snapped connection rod had peeled off little bits of the engine block inside, and this shimmering glittery oil/aluminum crap was all over the place:

lohko.jpg

 

I put it all in a parts washer to clean it roughly so biggest bits are gone and it's nicer to handle. Later i put oil and compressed air into the little oil holes all over the parts, and opened the crank dirt plugs (or whatever you call em in english) and cleaned the crankshaft:

hilut%2520pesuun.jpg

lohko%2520pesuun.jpg

 

Observant people probably noted that there are still bearings and stuff attached to parts, but as i said, this was just a first clean so i pretty much just dumped the parts there and let it rain, so it's nicer to touch them when they ain't covered in oily goo

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Then i sandblasted the engine pieces, and coated them black. This is when i cleaned with air and oil the little places, since it would be a bummer to have blasting sand in the oil channels to find their way to crank bearings and whatsoever. Pics:

24102012174.jpg

 

I triple-checked the torque of these bolts, and put locking glue in the threads and locking pins there too. No wild rods for me! Notice that i had originally (when taking this pic) put the con rods wrong. Can you tell what's wrong with the pic below?

24102012173.jpg

 

Rest assured, in this pic everything is going as planned and the con rods are properly installed:

24102012175.jpg

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Assembly goes on..

20112012203.jpg

All new strength 8.8 bolts in the block. And heli-coils where the bearing housing gets screwed in the block:

20112012206.jpg

Looking clean. The timing marks:

IMGP1533.JPG

Timing gears in place:

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You can see i have all new pistons, con rods, rod small end brass bearings, fitted in brand new and balanced piston pins. And of course all the other bearings and gaskets in the engine are new, and piston rings:

IMGP1537.JPG

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Then i went for the heads. Soda blasted these clean, since i will not be painting them. In the pic they're a bit wet at

some points since my gloves were soaking. It's not dirt:

IMGP1543.JPG

Then i lapped the valves of course:

hionta.JPG

It bums me how i for some reason have cleaned the lower head in the pic from the inside, but not the upper one...:

valmiit%2520kannet.JPG

Look at this pretty thing, got 2 new mugs straight from ukraine!

11122012213.jpg

They too turned black and got put in place:

motti.jpg

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Moved the rest of the bike in the same place as the engine, a back room in my workplace. What's the better place to

be doing this than a repair shop? All the tools imaginable are at my disposal. Here's some pics:

haarukka%2520irti.JPG

vain%2520runko.JPG

And here's the new color! Still wet, painted by me in my own workplace:

runko%2520maalattu.JPG

And here's what the paint job really looks like:

IMGP1558.JPG

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At this point i decided to rebuild the gear box, since it was very noisy with bad bearings, leaking gaskets and so on:

seuraava%2520osa.JPG

Loota%2520auki.JPG

I'm not even going to guess how all that mud got in there, but i know how it's going to come out:

ry%25C3%25B6n%25C3%25A4t%25201.JPG

ry%25C3%25B6n%25C3%25A4t%25202.JPG

I literally spooned the s**t out and kerosened the hell out of this thing. After wash, i wiped it thoroughly whit a rag soaking with fresh transmission oil:

puhas%2520loota.jpg

Oiled and cleaned and oiled again all the little things too. Some things were replaced, including of course the bearings and gaskets:

%25C3%25B6ljytyt%2520osat.JPG

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Then the diff. Started by cleaning it thoroughly, it was pretty good inside, all i did was greased it up a bit and changed the gaskets. And of course painted!

17112012191.jpg

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In the last pic you can see my new pipes, simple and loud! Also my mockup rear shocks, got them sitting on the shelf so i put them on til i have the old ones restored. Chrome is not what i seek in this project

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