Posts
450
Joined
11/19/2017
Location
Pittsburgh, PA, USA
Edited Date/Time
6/4/2019 6:54pm
13 yz250 I just picked up, ran it for 20min when I got home bike runs awesome and feels well jetted, pulled plug looks great.
HOWEVER, something ive never seen before, it is dripping out of the power valve hose on left side of cylinder and it is NOT spooge, it is 100% gearbox oil with clutch sheen in it. I can't imagine how gear oil is working it way up thru it. btw, bike does not smoke at all while running except during cold start up. so I don't think the crankcase seal is bad which would be the obvious reason if it was smoking out the exhaust as it would leak and get mixed in with the fresh air charge.
Bike has stated 30hrs on it and its mint, super tight fresh bike with fantastic compression. but having gearbox oil leaking from this is disturbing. if it was spooge nbd but....
please advise
HOWEVER, something ive never seen before, it is dripping out of the power valve hose on left side of cylinder and it is NOT spooge, it is 100% gearbox oil with clutch sheen in it. I can't imagine how gear oil is working it way up thru it. btw, bike does not smoke at all while running except during cold start up. so I don't think the crankcase seal is bad which would be the obvious reason if it was smoking out the exhaust as it would leak and get mixed in with the fresh air charge.
Bike has stated 30hrs on it and its mint, super tight fresh bike with fantastic compression. but having gearbox oil leaking from this is disturbing. if it was spooge nbd but....
please advise
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hopeful thats it.
thanks guys
Someone mentioned above I thought it was just premix.
Running less oil will make the fuel to air ratio RICHER.... which cools the combustion temps and results in a less complete burn and more drool, not the other way around. It's not as simple as less oil = less drool. The stock YZ jetting works very well at the recommended 32:1. Running less oil usually requires slightly leaner jetting.
I ended up putting 1.5hrs on it yesterday trying to get the suspension close and was really ripping on it with the new gas and oil. still making a mess on the shop floor out that hose with the 50:1. nothing out the exhaust at all. super crisp everywhere. went up to a 180main from 178 last night as plug was more white than my first test run w the bike. going to track Saturday with it.
suspension wise the kyb is WAY more suited to me than the AER setup. unfortunately the forks that just got done are valved too stiff (slow fork action) than I want. the shock I can get close and the spring on the shock is correct but have to now set the shock to be stiffer than I want just so it balances the bike to match the fork.. ugh.
Still have my "new" RMZ, waiting for a few parts to come next week before I can try getting it sorted out.
still thinking going TM144 as well
Pit Row
stock + shorty + rad valve
20 hours total.
175, 50, 1 1/8 turn AS, N3EW-3, 42 powerjet.
79 degrees, 500’ elevation
32:1 YAMALUBE 2R and 93 pump.
pics:
This was from about 15 minutes or so on the bike. I’m slightly retarded on timing too. .003” BTDC (stock is .007”).
could this all be from switching to 2R? I also messed up the premix so I could be anywhere from 3.7-4.2 ounces/gallon. Don’t ask, some dude was talking to me. That’s probably all that’s relevant.
save me! @FGR01
It's normal the power valve bleed off valve is there on purpose of bleeding off excess oil build up. Don't worry about it designed that way on purpose.
Some other oils may do it more than others. Sometimes it might have exhaust come out of it. Perfectly normal.
Heck yeah. Thanks man.
I've never been a fan of Yamalube 2R. I know it was very popular for many years but every YZ I have seen recently running it was a spooogy smokey mess. Not sure if they changed suppliers or formula recently?
Other than trying to make sure you put the right amount of oil in
I'll say N3EW-3 is pretty rich. I'd try dropping it to 2. I like the YZ250 with N3EJ-2 or N3CJ-2. Have to have decent fuel to do that.
Funny you say that also because since I switched the bike has been smoking more too. Smokey, spoogey mess is the best way to put it.
I have the needle set at 3 to compensate for the leaner PJ. Upon looking again, either I have a typo or MXA does. The needle in it is the optional needle that is the half-clip version of the stock one. So really I have it set at N3EW-2.5. If that doesn't make sense, I can check when I get home. I will regardless to clear up my notes now.
I had a bog off of extreme low idle (bike was barely staying running) and after getting the AS close I ended up just raising the idle some and now the bog is gone. It only happened if I let it idle way down like I said, and then stabbed the throttle wide open. It's resolved now. Anyways, that's why the jetting is the way it is. It all started with me running the suzuki needle lol. I've made my way back this far. By next month it'll all be completely stock again - cause boy it ran good then lol.
N3CW should be the 1/2-clip leaner version of N3EW. Sounds like you're running that on clip 3. Now I think I recall the other thread where you were messing around with jetting. Yeah I only ever used the Yamaha N3-series needles in YZ250's and never strayed far from the stock power jet. Never felt a need to.
Retarded timing and the W needles and Yamalube is going to be rich. I typically stayed around stock timing and the J needles. This can cause pinging with crappy pump gas so I usually ran at least 1/2 Avgas or this VP MS-100 they sell from the pump here. If you're going to stick with 93 pump, I'd probably run N3EW-2, stock power jet, closer to stock timing, and a better oil. I personally like Super-M and Motul-800. They both burn nice and clean for me at 32:1 in the YZ.
Yeah, that thread is my magnum opus lmao. Missed a ride day over that. I'm gonna grab some better oil when I get a moment.
The reason for the timing is to combat the detonation. It's difficult and frankly too expensive to run race gas by me. It really mellowed out the bike and made it more "linear" at .003. Still a monster but.. a monster with manners? idk. I do think a cleaner oil is going to make a difference.
Super M versus Castor 927, which are you going with? Maxima 2 stroke oils have gone up really bad in price.. Thats what prompted the 2R lol.
I pick Super-M over 927, just for the long term cleanliness. But if you have known good success with 927, that might be your ticket. I will say Super-M is cheaper than 927 and pretty cheap as far as high quality oils go. I've also tried K2 in the past and, for whatever reason, it always ran a bit less clean than Super-M.
SuperM is first pick since the smell of 927 gives me a headache. Sticks to everything too. I love it, but just a whiff. I don't want to bathe in it lol.
If it really annoys you. You can block it off. It's not really going to have negative effects. Just will allow more oil build up to pool up there. Which could mean maybe build carbon will happen faster or heavier.
On my one two stroke street bike. People run it both ways. They try n pass off the vented power valve covers as a track upgrade. Think of it like a carb vent hose over flow tube. Other than bleeding off the excess oil build up. It does nothing else.
So I’m right. It’s got an N3EW-3 in it currently. I recall doing this to combat the leaner PJ. I may leave it alone for now, it really barks honestly.
thoughts?
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