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A Dnepr Load of Problems


PazyrykTheGreat
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I'll spare the life story (since I was just writing it for over and hour and I click the wrong button and lost it) but basically I bought a Dnepr MT16 from Yuri online while I was on tour in Baghdad back in 2011 and dealing with both him and the motorcycle have been an absolute nightmare. He lied about it being make from unused parts and they are all worn out and complete crap. It has cost me nearly 3 grand in various mechanics and storage fees, not including the medical bills when I tried to take the transmission out last year where I got caught in the floor jack I was using, crushing my dominant hand and braking 2 fingers.

 

Anyways, so far I've replaced: pistons and rings (that were "close to catastrophic failure" as one mechanic put it), valves and springs (the ones in the bike shattered not long after I got it), fuel lines and petcock, head gaskets and various other gaskets, fuse box with modern fuses, and a heavier ground cable.

 

I've opened up the transmission, oil sump, timing cover and oil centrifuge and clean out all the gunk, which there was quite a bit for having only traveled 25 kilometers.

 

Sludge in the centrifuge.

CAM00040

 

Grimey oil pan.

 

CAM00041

 

Sump pan nice and shinny. Seriously, should there be this much sludge for only 25k? Unless these parts aren't new and this bike is old as ###### and was never cleaned.

CAM00042

 

Removing the rotten fuel line.

 

CAM00050

 

 

On to what's the current issue. After the cleaning I putting it back together (this time without any injuries requiring surgery), I was getting problems with the distributor. After figuring out how exactly it works (I am very inexperienced with this) I fixed it with a bit of carbon fiber rod, obtained from the local hobby and RC store, glued to the contact arm where it rubs against the spinny thing (that's a technical term).

 

CAM00051

 

And surprisingly it works. It did run a little bit but barely and wouldn't idle. It struggled a lot, shook and rattled and the left piston overheats. Today I glued another bit of carbon fiber rod to the points to give it some more adjustment room and the distributor makes and breaks the contacts which I can see with my little circuit tester, but now there is no spark in the plugs. Does this mean that there's now a problem with the coil?

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well all of Yuri's bikes are bits and pieces . as for the points i would go with a type 3 point less . and if its a Russian red coil then it probably dose not work i went with a Ural coil a lot of people go with Harley coils . and a lot of these bike you will find the rubber will be bad they have sat out side or stored so long that it rots out plus the Russian rubber is not that good

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I've never seen that type of points plate on a Dnepr and presume it is some form of US modification. Do what shoutou says and fit a complete electronic ignition/coil kit , you won't regret it.

Try Ebay 141185534081 for a type II or Ebay 151231076551 for a type III

 

Type III is more consistent but they are both easy to install and set up.

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The advantage is that you can use easily obtainable (in the U.S.) General Motors points, You can also adjust the dwell with the GM points set up, much more accurate than just setting the points gap.

 

If I need a set of points for my Dnepr, I'd rather go to the local auto parts store and pick up a set, than to order them off the internet and wait a few days.

 

Dave

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Thanks for showing me those starters on ebay. The digital ones look really nice but right now they are a bit out of my budget.

 

Here's the coil that's on the bike. It's got a good pulse from the distributor but no spark coming out. I take it that means it's borked? Is there a common compatible coil that I can get and any auto parts store?

 

CAM00053

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I have the same points plate for BMW on my R50. It is also described as being a solution to a problem that isn't there....but setting up the timing using the original method is a pain in the proverbial whereas the points plate is a cinch.

Mixing bowl of doom can't be that bad....or maybe the Marusho bowl of doom is the worst ever designed as one can replace that with the Ural one http://www.marusholilac.com/MarushoUralIgnitionMod.pdf

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The coil you show in the photo appears to be a Harley one, commonly used in the USA. Any twin output 12v coil with a primary resistance of 3.5-5.0 ohms will do the job. In Europe, one from a susuki GS550 or kawasaki Kz1000 is commonly used. Anything is better than the original cloth bound Soviet coils.

 

Do you know the procedure for setting the static timing? It is very easy once one gets the hang of it, also bear in mind that, whilst the ignition timing is specified at 34-36 degrees btdc. That was set in the days of leaded petrol and the bikes perform better with modern fuels if the timing is set a couple of degrees retarded from specification. Setting one too far advanced is asking for trouble. I have remarked all my flywheels and aim for 33-34 degrees. With standard timing marks, line the 'p' mark up to the bottom of the timing hole rather than the centre timing mark.

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Ok, no problem. Setting Dnepr OHV timing for dummies.

 

To make the job easy, get a bulb holder and 12v bulb made into a test lamp with 2' leads terminated with a small crocodile clip on the + wire and a large crocodile clip on the - wire. It will be usefull.

 

Look at the back l/h side of the engine casing, near the gearbox joint, you should see a rubber bung about 3/4" across. Remove this bung. This exposes a hole where you can view the periphery of the flywheel.

Put the gearbox in neutral and turn the engine over very slowly by tapping the kickstart lever. Look in the hole whilst you do this, as the engine revolves, you will see marks on the flywheel at certain points. The 'P' mark is for setting the ignition timing and is set at 36 degrees before top dead centre of the piston travel (BTDC) . The 'B' mark is top dead centre (TDC) and is the point where the pistons are at their outermost point of travel. These marks may be very feint so you may need to concentrate and possibly use a flashlight.

Tap the engine round until the 'P' line is opposite the engraved line by the hole on the crankcase. This is 36 degrees BTDC and is the factory recommendation for the point where the plugs fire when the ignition is fully advanced.

 

Fit the points plate and the cam assembly, then set the points gap at about 20 Thou. and have the points plate in it's central adjustment position

 

Now clip the small crocodile clip of the test lamp to the joint between the points and the wire that feeds them . Clip the other lead to ground.

 

Turn on the ignition and use a small screwdriver or similar to gently open up the timing bob weights to their most expanded position. The bulb should light up just as you reach this point. Keep trying whilst moving the points plate round until you achieve the setting. When it's done, tighten up the points plate screws and check again. Then turn off the ignition.

 

Now would be a good time to make the flywheel timing mark more prominent if you wish to check with a timing strobe. personally, I have the 'p' mark lined up with the bottom of the peephole rather than the engraved crankcase mark.

 

As you mentioned over heating pistons, now would be a good time to adjust the tappets whilst the engine is cold

 

Remove both rocker covers and tap the kickstart lever until the 'B" mark is lined up with the crankcase engraved line. In this position , one of the cylinders will be at TDC with both valves closed. Locate the correct cylinder by feeling for a gap on both tappets and set those gaps to 0.003-0.004 inch.

 

Turn the engine over exactly 1 revolution until the 'B' mark is lined up in the window again and set the tappets on the other cylinder to the same gaps.

 

Sorry if I'm teaching granny to suck eggs but thats as simple a procedure as I can write.

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Awesome thanks. I was wondering what that little hole was for. Of course it'll have to wait till I can get a new coil so I can try this out.

 

Does it matter that this engine is modified for an electric started and has a geared flywheel?

 

I thought the cylinder overheat was the carb not jetting enough fuel?

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Why do you have to wait for a new coil? These procedures can be done now as the tappets do not rely on the coil and the timing only relies on an earth path through one. Setting would work, even with a faulty coil as long as it's in place. Electric start makes no difference to the process. There could be many reasons for the overheat, one of them could be the exhaust valve not seating correctly, another could be incorrect ignition timing. In any case, both these things need need setting correctly before the carbs can be tuned and balanced. Only firing on one cylinder can cause overheating of that cylinder because it is trying to do all the work.

 

Do the ignition timing and tappets before thinking about the carbs. Once your carbs have been identified, there are plenty of simple instructions available on the net for setting them, but it cannot be done unless the rest of the settings are correct.

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For years I have been repairing, rebuilding dnepr engines, and I have heard a mulitude of fashions of how to accurately time one of the beasts. All are prone to small errors that can lead to failure when you are shooting for 36deg BTC. The following is the only fool proof way to get it right. Start with 36 deg was only called for for the 10-36 model. The performance change from the recommended

34 deg for the MT-11 is so small to be inviseable. Here's the way we do it at U-2 cycles

 

Put the bike on the center stand, block the front wheel securely( like tie it to a post) mount a fan in front to cool it, a box fan works well. Start the bike and shift it into 4th gear, you are now useing the speedometer for a tach, set the MPH for 45-50 mph. hold it there by use of duct tape or a helper. Now , with an electronic timeing light , set the timing mark in the timing window, and lock down the set screws on the points boix (whirling box of doom) That name was given to the points box by a sun baked aussie

because he didn't understand it IMHO. the system will work very well as designed and built by the Russians back then, it's when a shade tree engineer, with a hammer and screwdriver beats this thing up with advice from other shade tree engineers.. my own personal MT 11 has over 10,000 k with the same points and points box, with out so much as an adjustment. If you set things up as above you will find good stable operation, without the chance of detonation due to over advanced ign. watch for ice storms and blizzards, spring will be here in due time.....Ken

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