primary oil loss

[Jack Klarich]

Some of the Evo cranckcases were pourous and recalled, but I have never seen primary fluid leak into the crank case, usually they leak oil out, have you verified no leaks from the primary via the drain plug, I would put in some dye, good luck and let us know

 

[HDDon]

First welcome to the forum and sorry about your trouble. With the help of some really smart people here on the forum I'm certain you will get an answer. Since you just changed the stator, I would think that this is the place to start looking. With that much oil going somewhere if it was leaking outside the case you won't need dye. 18 oz of oil will cover anything behind the leak and some parts in front of it. I really believe that the only place that can hold that much oil is the crankcase. I don't have my manual here, but I think I remember a seal behind the stator. I'm going down to the garage to get my manual and I let you know if this is a possibility

I just checked and the seal I refered to behind the stator could be the cause of the loss of primary fluid. The thought I have is that the negative pressure caused by the pistons would draw the primary fluid into the crankcase if the seal has failed. As for the rest of the primary system and clutch, the heat from loss of fluid could warp the steels in the clutch and cause excessive wear to the chain and compensator assembly.

 

[Jack Klarich]

I just checked and the seal I refered to behind the stator could be the cause of the loss of primary fluid. The thought I have is that the negative pressure caused by the pistons would draw the primary fluid into the crankcase if the seal has failed. As for the rest of the primary system and clutch, the heat from loss of fluid could warp the steels in the clutch and cause excessive wear to the chain and compensator assembly.

This along with the pourous crank case could be the problem, the crank case would be over full

 

[HDDon]

Jack if he had a porous casting I think he would have had this problem before. This loss of primary fluid did not occur untill after he replaced the stator.

 

[karlsbike]

Firstly, you would have known it by now if that much primary oil went into the cases... Plus, as pointed out, this is totally unheard of - some few early Evo's had casting issues in way of the sprocket shaft case insert, but that lead to leakage the other way round.

Secondly, just curious, why did you take the inner primary off to replace your stator?
If you did, I have three suggestions:
1. Are you sure the large O-ring sealing the inner primary to the cases is good?
2. Could be a crack in your primary cover in way of the drain plug.
3. The jack-shaft is probably too high for any significant loss of oil, but your tranny input shaft (clutch out) is lower. Have you checked your belt & tranny pulley for any signs of oil? You could lose oil thru' there without noticing oil spill elsewhere.

Try this: Fill your primary up to the clutch spring as prescribed. Ride a few miles down a dry road, and ride slowly back carefully looking for any signs of oil.

 

[nvsteve]

I just checked and the seal I refered to behind the stator could be the cause of the loss of primary fluid. The thought I have is that the negative pressure caused by the pistons would draw the primary fluid into the crankcase if the seal has failed. As for the rest of the primary system and clutch, the heat from loss of fluid could warp the steels in the clutch and cause excessive wear to the chain and compensator assembly.

I think your on to something. If you are correct a simple check of engine oil level should provide the answer.

 

[HDDon]

I think your on to something. If you are correct a simple check of engine oil level should provide the answer.

Your right Steve, however if the oil is holding in the crankcase it will sooner or later sump out of the crankcase and than it will be mess in the AC and other places. I really think that the primary fluid migrating from the primary case to the crankcase is a long shot, but with the absence of fluid on the outside of the engine I am stumped to think of where else it could go.

 

[ridingagain]

Well guys thanks for all the thoughts and suggestions but I've ridden the bike 3000 miles since the oil loss was first noticed. And I was constantly inspecting and feeling for telltale oil residue. Found none at all anywhere. Before the teardown it was always leaking out by drain plug and I had gone into it deeper ( inner primary removeal) to change the jackshaft seal and the mainshaft seal on the tranny when I replaced the stator and rotor, so I also had the drive belt sprocket off. After teardown it had no indication of any oil leak after test drive so I took her on a 1400 mile trip... checking for oil at every gas fill; again not a single drop of oil anywhere. Late in the trip I noticed my primary chain starting to slap so I opened inspection cover and found very little oil left. Tightened up the chain, refilled with oil, and took another trip of 500 miles. I checked the oil level again; no sign of oil leakage but still it took another 2/3 quart to fill it to proper level. This happened (oil loss not chain problem) to me three more times during the summer. Always the same scenario. As for damage to any parts; no evidence of heat damage or excessive wear. Clutch works great, chain and sprockets look fine too.

 

[HDDon]

So we have no fluid dripping off the underside or rear of the bike. We have no excessive fluid build up in the oil tank. There is no oil pucking up from the bowels of the crankcase. If I didn't know better I would think this is like the story of a neghibor adding and subtrackting gas to his next door neighbors car.

 

[Hoople]

We have no excessive fluid build up in the oil tank.

Don, I know with my ride, as soon as the oil level goes near the full line, it starts pulling the excess to the air cleaner and I burn it. Would it be possible to weep 16oz over the course of 500 miles into the intake? The level in the tank would remain flat as long as the primary xfer was slow enough.??

Seems far fetched to me but would it be even possible?