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93 should be head breather. You stated blind holes in heads, and some what of a basket case.
My guess from those clues is not original engine/ original heads. Might look at an earlier than 93 oiling diagram/ breather route from the case.
Ok, so 93 is head breather for sure. So the engine more then likely isn't correct for the year unless you can buy different jugs from and early engine which would fit on a later crank case. I'll do that, would explain the weird location of the engine oil filter and the fact that there very little room for the oil lines to the pump.
It just dawned on me that this is a head breather engine...
Are the breather openings clear?
The engine breathes through hollow bolts that hold the air filter backing plate on.
You may need to remove the rocker boxes and replace the umbrella valves.
But do the compression and leak down checks first, make sure the issue isn`t simply a worn out top end.
The hoses in your pic are:
A= Oil supply from bottom of oil tank to oil pump.
C= Oil from pump to oil filter
B= Oil return from filter back to tank.
The hose just beneath the bracket is the oil tank vent hose (crankcase to oil tank).
OK, so It seems that this engine, I guess is an early evo engine which isn't as head breather ( Not really sure how the evo engine time line works) because the bolt which would be the breather banjo bolts are just standard bolts and the threaded holes are just blind holes in the jugs. There is not visible passages and they where completely dry, no oil in them what so ever.
You are correct on all the hose locations as depicted in my photos.
SO, I need to find out where an early evo breaths I guess.
The Factory Service Manual is a must. Not cheap, but not usually more than an hourly rate at a shop. The Clymer et. al. is a catch-all of models and dates. Not much help past simple maintenance.
I wonder if someone put bottom breather heads on a top breather bottom.
Works great if done the other way around
Top breathers started in 1993 and I agree the HD Factory Service Manual is a must, even they don't help much on some bikes concerning oil hose routing.
I may not be "seeing" the photo correctly, but looks to me like there is a plug in his crankcase breather fitting hole, as shown in Daven's photo at the yellow arrow. (Good catch Daven)
If that is a pipe thread plug, there should be a fitting and a 3/8 hose connected to it, and vented to the atmosphere.
Great eye! I can confirm that is a threaded plug with thread sealer on it. So that must be my breather port.
New problem: No clearance to install a fitting in breather port because it lines directly up with the oil return line fitting. ( This can be seen in photo)
Possible solutions: Getting a plug the size of the filler neck , drilling a hole through it and attaching a filter and running it like that OR drilling a hole in the valve covers , attaching filters if that will work.
I am aware this isn't the correct way of doing this. I understand it will look awful but I would rather not pull the engine until I absolutely have to and especially when the short riding season here is in full swing. Even if I where to pull the engine I'm guessing at the very lest I would have to change jugs to head breathers and while I'm at that I might as well freshen up the top end. That all sounds like winter work to me.
I guess I'm asking if anyone believes it will cause any damage to run the engine in this state. I will have to change oil sooner but that is accept to me.
Possible solutions: Getting a plug the size of the filler neck , drilling a hole through it and attaching a filter and running it like that OR drilling a hole in the valve covers , attaching filters if that will work.
Forget that idea...
Originally Posted by Zannarack
I guess I'm asking if anyone believes it will cause any damage to run the engine in this state. I will have to change oil sooner but that is accept to me.
I would not run the engine without the breather system properly configured, there is no work around for this.
You must have a breather at the crankcase nipple location, or put `93 or later heads and rocker boxes on the engine.
Another thing to think about is the timing cover, there is a different part number for head breather vs case breather.
Last edited by Dan89FLSTC; Jul 15, 2020 at 04:55 PM.
I would not run the engine without the breather system properly configured, there is no work around for this.
You must have a breather at the crankcase nipple location. Or put `93 or later heads and rocker boxes on the engine.
Another thing to think about is the timing cover, there is a different part number for head breather vs case breather.
I totally agree.
Without the engine number, cant say for sure, but there's a good chance it actually is a top breather with the incorrect heads someone installed, who knows...
Thing is - if it is a top breather engine, it won't have the correct baffle set-up in the cam cover and oil return cavity. Putting a fitting/hose in that spot will let it breath somewhat, but will let it slobber oil all the time out that hose.
I'd pull a valve cover and see if it has the correct (top breather) rocker covers. If it does, you can get those heads drilled/ported by an experienced machinist who is familiar what that operation. (There are a couple on here that I know of) Or, buy some used top breather heads, have them serviced and replace what you have.
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