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Discussion Starter #1
Ahhh but yet ANOTHER problem with the old 750. So I have literally put no run time on the bike yet because I have been to busy working on it.

Well here is the deal, today I thought I’d go get the bike inspected and get it legal for the first time in 4 years.... well anyhow the rear exhaust manifold is covered in oil, the rubber motor mount above the manifold has oil on it as well. Where the exhaust hooks into the manifold smokes quite a bit when motor gets warmed up.... thtiming chain tentioner has oil on it as well and oil running down the motor above the tentioner. My guess is the weep hole, or half the problem anyways.

So what I’m wanting to know is could the weep hole cause oil to be all over the manifold? I wouldn’t think so seeing how it’s kinda below the manifold.... bike does smoke a little when warmed up, nothing major at all..... I was thinking maybe the bike had to much blow by causing oil to get into the manifold, but seeing how it’s on the outside of manifold as well and the motor mount... could the weep hole actually be the problem? I can’t get it inspected with smoke rcoming off the exhaust the way it is lol
 

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Sounds like maybe the rear valve cover.
 

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Discussion Starter #3
Sounds like maybe the rear valve cover.
I thought the same thing, but valve cover seems to be fine. I ran my finger all around it. No oil on it... Only leak I can find wth a quick look was that weep hole... but bound to be another somewhere else. Surely if rings was bad enough to let that much oil out the ol bike would smoke like a train.
 

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I thought the same thing, but valve cover seems to be fine. I ran my finger all around it. No oil on it... Only leak I can find wth a quick look was that weep hole... but bound to be another somewhere else. Surely if rings was bad enough to let that much oil out the ol bike would smoke like a train.
Yes, if it was pumping raw oil, it would be smoking too.

Eliminate the weep hole leak (plug well o-ring), clean it up and see where you are.
 

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Discussion Starter #5
I thought the same thing, but valve cover seems to be fine. I ran my finger all around it. No oil on it... Only leak I can find wth a quick look was that weep hole... but bound to be another somewhere else. Surely if rings was bad enough to let that much oil out the ol bike would smoke like a train.
Yes, if it was pumping raw oil, it would be smoking too.

The plug
Eliminate the weep hole leak (plug well o-ring), clean it up and see where you are.
I want to toss some new plugs in so I decided to pull the old ones out and inspect them. I noticed oil around the plug when removing the spark plug wire,

After pulling the plug it seemed to have oil on the tip of the plug a good amount of oil at that....

The spark plug across from it on other side of cylinder was dry seemed fine. The one that was wet was on the plug well side.... I used a snake cam to inspect the piston area the best I could....

piston seemed little wet or looked that way to me. I will upload a picture.... now I’m thinking valve seals or rings? But then again wouldn’t both plugs be covered in oil if it was the rings? First picture is spark plug well
 

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If the plug well is holding oil, the spark plug starts getting coated as soon as you break it loose.

Looks more like carbon on the piston, and not too severe. Yes, both plugs should show it if it's pumping oil.

Everybody should have a snake cam! :cool:
 

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Discussion Starter #7
Here’s a couple pics of what I’m talking about, maybe it will help a bit.

First pic On the exhaust where it hooks to the manifold, that chrome collar that I set my spark plug wire on is where it smokes from and that little mount/bushing above it gets oil bubbles off it.

I took my phone and put it under the manifold and snapped a picture to show how everything’s wet. Valve cover not showing any signs of leaking... I know for sure the weep hole is leaking oil...

It for sure has me puzzled on how oil has gotten everywhere like this 🤔 going to see if my local part store has the correct o rings for the spark plug well in the morning.
 

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Isn't there an o-ring in the deep-well spark plug holes or something? I've heard of other users needing to replace that then it starts to leak and fill the plug well.

The plug well screws out of the case using a large hex (people report using the axle nut to remove it) then the o-ring is replaceable from what I remember reading about it.
 

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Discussion Starter #9
Isn't there an o-ring in the deep-well spark plug holes or something? I've heard of other users needing to replace that then it starts to leak and fill the plug well.

The plug well screws out of the case using a large hex (people report using the axle nut to remove it) then the o-ring is replaceable from what I remember reading about it.
Yes you are correct, main thing I’m trying to figure out atm is why my manifold is covered in oil. I could see a leaky valve cover gasket causing the problem but it’s not leaking.

The weep hole is on opposite side of motor below the manifold so I can’t see that being the problem either. It’s not a old leak because I have fresh oil dripping down from somewhere.

Unless the weep hole is just blowing oil everywhere, but I’ve only heard of them being small leaks running straight down the motor.
 

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Not trying to offend, but ... Are we sure it's coolant? Did you taste test it? :)

The rear weep hole is much lower then the manifold, almost at the base of the cylinder.

Rear coolant pipe is ahead of, and higher, than the manifold.

 

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Discussion Starter #11
Not trying to offend, but ... Are we sure it's coolant? Did you taste test it? /forum/images/smilies/smile.gif

The rear weep hole is much lower then the manifold, almost at the base of the cylinder.

Rear coolant pipe is ahead of, and higher, than the manifold.

It’s most definitely oil, even smells like oil when burning off the exhaust. It’s not a coolant leak.
 

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Take some spray brake cleaner and completely clean the oil off the entire area. It may take a lot of it, get the Walmart Supertech brand. Once clean and dry, get some Arrid Extra Dry spray, and spray the whole area with it. It is bright white, and any oil leak will instantly become visible. Start the engine and wait. You can also get dye to put in the oil that shows up under a blacklight. I seriously doubt it is coolant, that is quite different from oil. However, there is a coolant elbow fitting on the left side of the rear head that tends to leak. It has an O ring on it, but even with a new O ring, it can leak if you wiggle it around. And yes, I have done the taste test on coolant. Obviously ethylene glycol is poison, and you don't want to swallow any. I just touch it with my finger and touch my tongue to it. If it is coolant you will immediately get that sweet taste. Spit it out. It will never be anywhere near your throat.

You might also want to remove the gas tank and run the engine on a temporary gas supply. You can get a much better look at the top on the engine with the tank off.
 

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Discussion Starter #13
Take some spray brake cleaner and completely clean the oil off the entire area. It may take a lot of it, get the Walmart Supertech brand. Once clean and dry, get some Arrid Extra Dry spray, and spray the whole area with it. It is bright white, and any oil leak will instantly become visible. Start the engine and wait. You can also get dye to put in the oil that shows up under a blacklight. I seriously doubt it is coolant, that is quite different from oil. However, there is a coolant elbow fitting on the left side of the rear head that tends to leak. It has an O ring on it, but even with a new O ring, it can leak if you wiggle it around. And yes, I have done the taste test on coolant. Obviously ethylene glycol is poison, and you don't want to swallow any. I just touch it with my finger and touch my tongue to it. If it is coolant you will immediately get that sweet taste. Spit it out. It will never be anywhere near your throat.

You might also want to remove the gas tank and run the engine on a temporary gas supply. You can get a much better look at the top on the engine with the tank off.
Awesome advice I didint think much about trying something like that. I appreciate the help! I’m going to give it a shot. I know that little hole next to tensioner leaks oil for sure. Hopefully I can have it fixed tomorrow.

And by chance does anyone know what size the axel nut is on these bikes?
I’d like to know the correct size so I can find another one and just make a homemade tool, that’s way I don’t have to keep taking the rear axel but off when I need to remove the spark plug wells
 

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And by chance does anyone know what size the axel nut is on these bikes?
I’d like to know the correct size so I can find another one and just make a homemade tool, that’s way I don’t have to keep taking the rear axel but off when I need to remove the spark plug wells
27mm

Just checking about the antifreeze, can't be too sure when you're looking from 1000 miles away. Have seen people mistake antifreeze for clean oil before.
 

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the airflow around the engine can easily cause a leak to seem to come from somewhere else. we know the weep hole leaks.. maybe airflow around engine when riding is blowing it up onto the back of the cylinder?
 

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Someone gave me a battery powered black light for Christmas. Antifreeze will glow under a black light, but you need dye for the oil. Small bottle of dye is $5-8. Peanut butter glows green! So does ketchup.

The light couldn't be real expensive, but it has a laser, LED flashlight, LED floodlight, and LED black light.
 

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Discussion Starter #17
the airflow around the engine can easily cause a leak to seem to come from somewhere else. we know the weep hole leaks.. maybe airflow around engine when riding is blowing it up onto the back of the cylinder?
I have not yet had a chance to ride the bike, seems like every time I fix a problem another occurs.
 

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Someone gave me a battery powered black light for Christmas. Antifreeze will glow under a black light, but you need dye for the oil. Small bottle of dye is $5-8. Peanut butter glows green! So does ketchup.

The light couldn't be real expensive, but it has a laser, LED flashlight, LED floodlight, and LED black light.
I had no clue antifreeze glows under a black light. I guess I learned something new today! I think I will by a small one, wouldn’t hurt, I’m sure it will come in handy.
 

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Discussion Starter #19
One more question for you guys, when I got to change these o’rings on the spark plug tubes- before pulling the tubes out is the valve covers suppose to be removed first? If so what’s the purpose in that? I’m just curious I read somewhere else that the valve covers needed to be removed in order to pull the spark plug tubes out
 

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I Can't think of any reason why you would need to take the valve covers off the tubes they only come out so you can thread it through the cam chain otherwise you would need a split link in the cam chain which is not a good idea
 
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