Question why would someone leave out this crank bolt? opinions welcome

[motoauthentica]

upon removing the crank from the lower end of a basketcase project i found a bolt appears missing from the crank , it looks to go to the sludge trap, this lower end was absolutely FULL with nasty sludge film on everything it took hours of soaking and cleaning, i started thinking the last person to have this apart did they leave this bolt out on purpose?? to maybe try and keep the sludge trap drained or cleaned while running? is that a common old school trick or am i just wild speculating. also the trap plugs on both end are heavily peened and im having a hard time removing the plugs any suggestions on removal tools etc??? thanks so much. I LOVE THE FORUM AND THE AMAZING PEOPLE ON IT<<<<<

[muskrat]

G'day Greg.
This is why we mention to every new owner "check the sludge trap". Lucky you did. With that bolt missing the motor would have lasted 5 minutes tops.
That bolt positions the sludge trap tube.
The plugs need the center pops drilled. 1/8" drill just till they clean up. Yours don't look too bad. A good quality impact driver will get them out.
Cheers

[Swarfcut]

  moto.... Some good news to add to musky's post.
             
 The crank you have is the so called big journal type and is an improvement on the earlier design. This has larger diameter big end bearing journals and improved oil flow between them via the sludge trap which is located by that missing bolt.

  The end plugs must be removed and the inner cross tube extracted. Some come out easily, some need major surgery, no if's or but's it has to come out and the whole lot cleaned up. Aftermarket parts are available if original parts have to be destroyed.

 This is well described in many posts on the forum, along with tricks to remove those end plugs. Plenty of YouTube videos as well. Search down that bolt hole see if the thread for the bolt is still there.. I'm assuming the bolt is missing.... Not sheared off.

 Examine the crank cases for damage. Engine number series should be DA prefix  and should have matching numbers stamped under the dynamo mount on the front face.

 Swarfy

[CheeserBeezer]

When refitting the sludge trap it is very important to ensure that the narrow end of the tube is sealed against the extended nose of the plug on the drive side of the crankshaft. The aftermarket sludge tubes are very poor, so if you can get yours out without damaging it, that would make life a lot easier for you. Thought I'd mention it now, before you do anything brutal with your sludge trap tube! It should be possible to get it out using petrol to dissolve the sludge around it. Generally speaking, pattern parts often cause more problems than they cure. Try to fettle what you've got if you can.

[Klaus]

A good advice is to renew the two other bolds also. I have two engines lost a bold by about 70 miles, not a pretty sight.

regards Klaus

[motoauthentica]

THANK YOU !!!!! THE VALUE OF EVERYONES COMMENTS IS LIKE GOLD<<<<<<

[Klaus]

Oh I guess these bolts are more cheaper as the damage they left.

regards Klaus

[motoauthentica]

Oh I guess these bolts are more cheaper as the damage they left.

regards Klaus

HOLY COW !!! boy thats a bad day, i hope nothing like that ever happens again to you

[Klaus]

Oh this was the first time, a few month ago an other engine failed the same way
That s why I stongly recomment the renew this bolds.

regards Klaus