Blown Crank Seal - Effects on Jetting

[Faded]

Okay, I'm begining to think my bike (02 CR265) is sick.

I sent it off to Eric Gorr back in January to be rebuild from top to bottom. We decided this would be best because of the dirt that was digested through the 02 CR's leaky air box. So in went a 2mm oversized piston, hot rod, bearings/seals and out came the excess cylinder/head material that Eric is so good at removing. When I go it back I heat cycled it three times as suggested, waiting a day between cool down periods.

I've only put 25 easy hrs on it since the heat cycles (no racing). This being my second real bike it's also taken me this long to get the jetting somewhat close. The last two times I've ridden it I've noticed that it seams really lean on the bottom. The second to last time I rode it back in June (I suffered a broken rib and knee surgery after that ride) we were riding trails. The bike was running fine when we started. After about an hour it started knocking really bad. I stopped, parked in the shade and started looking the bike over. It was so hot that coolant was seeping out of the head studs. It was getting really hot out so I figured that the heat was getting to it. After it cooled I made a trip back to the truck and went to a richer needle (BEY30-74 from the 30-75 I had in there, still on the 2nd clip) and turned the air screw in a quarter. It was still having trouble. I went one step richer on the needle again (30-73) and raised the clip one notch (3rd position). It was better, but not right. I figured that I had gotten a tank of really bad gas or something. It wasn’t knocking or overheating anymore, but you could tell it was lean on the lower circuits.

Fast forward to this last Thursday, I tried to go riding again. I drained the tank of the old nasty gas; bought some Sunoco 110 for some added protection (we were going to ride the sand dunes) and installed the S-9 nozzle, taking the place of the S-8 I had been running. I ended up retaining the 30-73 needle but went to a 360 main (up from 350). I didn’t want any trouble. I also changed the trans oil, and noticed that it didn’t seem like enough came out when I drained it, but I was eager to ride (C’mon, it had been like 6 weeks by now). I filled the tranny an proceeded to get loaded up. When I got there the bike coughed and sputters up until about 1/3-1/2 throttle. I noticed that it’s blowing splooge all down the front of the bike where the manifold bolts to the cylinder. Splooge is also dripping out of the bottom of the silencer onto the swingarm. It’s never splooged this bad, even on stock jetting.

So, does it sound like a bad right side crank seal? What could have caused this? I’ll try and drain my cases to see how much oil I’m missing after my short ride last Thurs. Any other thoughts are more than welcome.

Thanks in advance,
Andrew

P.S. Sorry for the long post.

 

[Mr. Clean]

Sounds like you are sucking lots of tranny oil either from the crank seal or thru the crankcase itself.

 

[Faded]

Well, I drained the cases last night to see how much I was missing (It ran for 1.4 hrs on Thurs with this fluid). To my suprise I came up with about 960mL of fluid. I usually run 1 qt (946mL), so I was suprised that I wasn't missing much if any at all. The excess was probably from not getting all the fluid out the time before. I pulled the plug though and it's as black as can be. Is there any other way of checking for a blown crank seal besides tearing it apart?

Thanks in advance for any help anyone can offer.

 

[ericlachance]

the only other way I know of is through a leakdown test...

 

[Moto Squid]

Originally posted by ericlachance
a leakdown test...

:thumb:

 

[billtx]

If you had a blown right side crank seal you would have noticed a big change in oil level. I just had my right side seal go out, it used 150cc oil in about 8 laps at the track. If you just had your engine rebuilt, it is probably OK. Must be something else going on. The leak down test will work, but I suspect it will check out OK.

 

[tre633]

I think if your clutch-side crank seal was out, you'd notice a loss of case oil, although it may not be a whole lot. Also, your plug would be fouling. Check your spark plug to see how it's burning. (Brown is ideal) However, i wouldn't rule out a clutch-side (right) crank seal.

 

[Faded]

I'll try and get a pic of the plug and post back.

 

[bclapham]

the world of the TMX carb...........

......Faded, i think this is a jetting thing, was there tons of spooge when you had the carb with the leaner needles etc- i might bet, if it was sucking trans oil, then it would have spooged then also?????

where is your ignition and what heat range plug are you running btw? FWIW, the richer/leaner mikuni needles thing is a bit of a misconception, eg when you go from say 78 to the wider 79 the only thing that does is leans it from 1/8-1/4 throttle, about the same over lap with the slide.

sorry i cant help more. good luck

 

[Faded]

Originally posted by bclapham
the world of the TMX carb...Faded, i think this is a jetting thing

Could possibly be...I really haven't ruled that out yet. Funny is that it's like everything fell apart during that ride in June when it over heated. I really haven't been able to ride it much to determine exactly what it is. Read on...

was there tons of spooge when you had the carb with the leaner needles etc- i might bet, if it was sucking trans oil, then it would have spooged then also?????

When it was set up leaner I had almost zero spooge. Now the front of the cases by the manifold are covered and it's oozing out of the silencer body retaining screw onto the swingarm.

where is your ignition and what heat range plug are you running btw?

Ignition should still be stock unless Eric modified it when he did all the work (which I doubt). I'm running a BR8EG plug. I ran it at the dunes, so it should have been adequate (mostly WFO).

FWIW, the richer/leaner mikuni needles thing is a bit of a misconception, eg when you go from say 78 to the wider 79 the only thing that does is leans it from 1/8-1/4 throttle, about the same over lap with the slide.

Yes, and I've been having a lot of trouble getting rid of 1/8-1/4 trottle bogging. I've tried quite a few combinations and haven't been able to get it right. Now it seems as if the problem extends way beyond 1/4 throttle to almost 3/4 throttle. I've conversed with a few other 02 CR onwers on this board to try and figure out my jetting (thanks to all, you know who you are!) but I still can't get it. It seems as if my problems have compounded and I want to try and rule out the mechanical stuff first. I have a set of rings and a gasket set to do a top end. I think before I install these I'll use the gaskets as a pattern to make some drawings and have an intake and exhaust block off plates made and do a leakdown test. Then I'll check compression, timing and install the rings/gaskets. This should atleast let me know that the motor is in check and then I'll refocus on jetting. :whiner:

If anyone has anything to add, please chime in. This is only my second year riding/working on my bike, so I am open to ideas and opinions.

Thanks to everyone that has replied, I appreciate it.

P.S. Anyone else out there have a case-reed CR265?

 

[bedell99]

Whats up Andrew,

First, I think you might of cracked your exhaust flange. (I'm on my 4th) Take off your pipe and check. Second i think you are running way to rich needle. It sounds like when you where running in the woods it ran super rich. I hardly ever get the bike cleaned out when running in the woods. I think a leaner needle might be the ticket. I also think your bike was knocking becuase you where riding slower thru the trails and the bike couldn't cool itself, plus pump gas in that situation is bad. It was definetly detonating. 3rd, after you get all the jetting figured out. Repack your silencer, it is probably filled with alot of crap and put an new plug in. Also that sunoco 110 has some really bad distillation numbers and is not good for our applications. Maybe Rich or Nephron can further elaborate on all the little details about that fuel, but from what i have heard it's evap curve is better for hi compression race cars.

Erik

 

[Faded]

Erik,

Yea, I'm still working on the jetting thing. The funny thing is that it runs stronger/better with the richer needles. :ugg: I still can't figure this thing out for the life of me.

Originally posted by bedell99
First, I think you might of cracked your exhaust flange. (I'm on my 4th) Take off your pipe and check.

Yea, I need to do that too. It's on the list.

I also think your bike was knocking becuase you where riding slower thru the trails and the bike couldn't cool itself, plus pump gas in that situation is bad. It was definetly detonating.

It was even doing it when going down the dirt roads in 4th-5th gear (not pinned). It was really bad on the trail (mid 3rd gear most of the time) but still present just going down the road.

Repack your silencer, it is probably filled with alot of crap and put an new plug in. Also that sunoco 110 has some really bad distillation numbers and is not good for our applications.

I did the silencer and the plug about 2.5hrs ago. I agree on the gas, but it's really hard to get anything else around here. The only reason we can get the Sunoco 110 is because of the IMCA stock cars that run around here. Besides, all race gas is the same and the only thing that matters is the octane, :| at least that's what all the gas suppliers in my area say. I inquire about the distillation curve and they don't have a clue, "But it's 110 ocatane, it should work. :silly: