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Discussion Starter #1
I know this is cheesy, but I am having a hard time positively identifying which parts I need to fix a leaking Left side cover. The only psrt that doesn't seem to have multiple different looking parts during a search is the gasket itself. However, I know that there are seals in there that I might as well take care of while I am at it. I was told there is a PCV valve too? And it maybe a good time to add a tooth to the sprocket as well (used for commuting more than trails).

It blew on me today while on my way to work. Thankfully I didn't blow any internals, but I will trailer her home tonight.

There are bubbles coming from the circled area in the first pic:





 

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Here is what things look like underneath your left side engine cover (this is a pic of a TTR225 engine, but the insides look about the same as a TW200). The area that you have circled in your first picture does not appear to have any pressurized oil galleys, so any oil leaking from between the engine side cover and the crankcase must be coming from oil that is flung from the spinning crank and flywheel assembly. This should not present a serious functional problem beyond making a bit of a mess on your engine and possibly your pant leg. Just keep an eye on your oil level and it should be okay to ride until you are able to replace the side cover gasket.

100_4564.JPG

The engine seals that are accessible under the left side engine cover are the output shaft seal seen in the upper right of the above picture and the shifter shaft seal seen in the center right of the above picture. The TW engine has no PVC valve.

I would double check to make sure that the oil is not coming from a base gasket leak at the bottom of the cylinder.
 

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Last time I went in that side of the case I found genuine Yamaha OEM seals only cost about 3 bucks a piece - got them from the UK ebay

There are three seals you’ll need – one on each end of the shaft with the front sprocket, (they both recess into the inner or outer crankcases) – and one for the shift lever (which I keep telling myself is “optional”, because I didn’t bother with it)

The big gasket (which comes a part of a kit containing some others as well), again the OEM stuff is fairly cheap – when you have the parts installed and go to put the outer crankcase back on, the magnets on the stator will pull it all over the place – watch out you don’t pinch the wires coming from the stator at the top (easily done)

Next up – be aware that the various screws are “JIS” (Japanese Industrial Standard), and not the standard posi-drive they look like. A set of JIS screwdrivers are readily available, start with Fleabay and see how you get on (good investment anyway)

If you do decide to change the front sprocket, expect the sprocket to have a degree of “float” on the shaft – this is perfectly normal and prevents undue wear. Having gone to the trouble of replacing the front, it might be a good time to replace the rear, and get a new O/X ring chain on there. The bolts holding the rear sprocket have three sets of “tabs” that fold over the bolts to prevent escape, and it is recommended to replace these each time they are removed (again, it’s cheap to do, and good practice, as they can break when re-folded over the bolts)

And just when you thought my advice had cost you enough money – get rid of that stock front tire – you want the Shinko 241

Have fun ……
 

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Discussion Starter #6
I can only think of 5 seals right now and the picture shows 6: Output shaft seals (inner and outer), the shift shaft seal, the clutch lever seal (on top), and the kick start shaft seal. What am I missing?
It says whole engine so maybe one that is not on that side?
 

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Discussion Starter #7
Last time I went in that side of the case I found genuine Yamaha OEM seals only cost about 3 bucks a piece - got them from the UK ebay

There are three seals you’ll need – one on each end of the shaft with the front sprocket, (they both recess into the inner or outer crankcases) – and one for the shift lever (which I keep telling myself is “optional”, because I didn’t bother with it)

The big gasket (which comes a part of a kit containing some others as well), again the OEM stuff is fairly cheap – when you have the parts installed and go to put the outer crankcase back on, the magnets on the stator will pull it all over the place – watch out you don’t pinch the wires coming from the stator at the top (easily done)

Next up – be aware that the various screws are “JIS” (Japanese Industrial Standard), and not the standard posi-drive they look like. A set of JIS screwdrivers are readily available, start with Fleabay and see how you get on (good investment anyway)

If you do decide to change the front sprocket, expect the sprocket to have a degree of “float” on the shaft – this is perfectly normal and prevents undue wear. Having gone to the trouble of replacing the front, it might be a good time to replace the rear, and get a new O/X ring chain on there. The bolts holding the rear sprocket have three sets of “tabs” that fold over the bolts to prevent escape, and it is recommended to replace these each time they are removed (again, it’s cheap to do, and good practice, as they can break when re-folded over the bolts)

And just when you thought my advice had cost you enough money – get rid of that stock front tire – you want the Shinko 241

Have fun ……
All good advice. Costly, but good.

Unfortunately, the tire has to stay a bit longer. I was looking at these (https://www.jpcycles.com/product/zz28199/shinko-sr428-180-80-14-rear-tire) as I do 80/20 on this bike and mostly established trails when off pavement. Seem kind of close to the 705's I run on my DL650 and I like those. The rear and chain are only 2500 miles old and in decent shape. I wouldn't even do the front except I don't plan on pulling it apart again when the others are due. I am getting a 15T front to hopefully help a bit on the highway (55mph) during my commute without hurting the slow gearing too much.

The rest of the parts I may not run OEM, but I will replace them as I can. The JIS set I will grab too. I doubt this will be my last time taking a cover off this bike.
 

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Clean the engine so there isn’t any oil on it, spray it with a foot spray that leaves a white powder and you will see the powder get wet exactly where it’s leaking.

Ronnydog
 

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Clean the engine so there isn’t any oil on it, spray it with a foot spray that leaves a white powder and you will see the powder get wet exactly where it’s leaking.

Ronnydog
Very smart idea...thanks!
 

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Discussion Starter #10
Well, she's apart. I will be replacing the seals, front sprocket, and gasket. However I now know why it leaks though how two bolts got finger loose after 23 years is still a mystery. Already had the parts so kept going.
 

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I ref to the pic above of the split case, I'm trying to visualize in my head exactly where the stator wires are to route to keep from getting crushed on assy. (as the previous owner on my bike has done). My wires are a crushed up birds nest. I thought the wires were cut and taped back together by the glob I found, but I think it is just the grommet that has deteriorated over the years. I am going to attempt repair by soldering back together the crushed wires, if that doesn't work out will replace with a new Chinese knock off stator assy. And, another thought, isn't there some way to affix or maybe lightly glue those wires to the cover just enough for proper re-assembly?
 
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