200cc MKII Oil Consumption

[v330123]

Guys:
I went for a ride yesterday with my wife following me for a short distance. Later, she said that the left pipe smokes quite a bit more than the right. It must have been substantial for her to notice it. Anyway, I do notice that after a ride, I wipe the oil specks off of the left side exhaust baffle, but there's none on the right side baffle.

Since I got the bike running again, I've racked up about 320 miles. I just started running gas only in the tank, and have calculated an actual oil consumption rate of 19.5 to 1. Of course, that can be adjusted. But, I don't think I can adjust the oil rate to one cylinder only. The oil plumbing to the right side cylinder looks good. Nothing leaking. And, I still do get some dirty oil accumulation around the end of the right muffler, just not as much as on the left.

When I tested the pump, I saw a similar oil delivery rate from each output. Has anyone else noticed one cylinder smoking more than the other? Reason for concern? Is my right cylinder running lean of oil? Or, is my left cylinder running to rich of oil? Is there any way to tell?

Thanks.
Gary

[rocketman]

Deteriorating oil seals can cause excessive smoke. An overly rich carburetor can too. Does the smoke itself smell of excessive two stroke oil,burnt motor oil(seal),or fuel(carb)? These are general mechanical concerns, but might give you a starting point. Keep your eye on the crankcase oil level. If it is a seal and the case runs dry,you're going to have more trouble. As far as an oil lean/rich cylinder,a good plug reading should tell you. With little gas smell or wetting-dark/oily is rich,lighter tan to white is lean. Nice light brown/tan is what you want. A gas wet plug will show a rich carb. Can anyone confirm that the left crank seal is a wet seal? Mark.

[OldSwartout]

The left crankshaft seal is a wet seal, sealing off the crankcase from the oil pump drive gears, which are fed by a small trough and hole from the transmission oil.  Your symptoms indicate that seal is bad.  Fortunately it is very easy to replace, and I'd assume Richard or CPC would have them.  Check your transmission oil level before you ride it again, it is probably low, although it doesn't take much oil to make extra smoke.

[v330123]

Mark,

Thanks for the ideas. I think the exhaust smoke is two stroke oil. But, I'll have to closely check the transmission oil. I never thought of the left seal leaking transmission (and thus oil pump oil) into the crankcase. I wasn't sure what you meant by "wet seal" until I read the note from OldSwartout. I installed all new crankshaft seals at time of rebuild, but I know I could have gotten a bad one. Or, there could be other problems with sealing. And, other than idle, I didn't make any adjustments to the carbs. They're both brand new from RC. That's something else I'll have to check. Also, I'll take a close look at the plugs.

Between you and OldSwartout, I have some things to check now.

Gary

[v330123]

OldSwartout,

Thank you too for the ideas and tips. Perhaps you've read my reply to Rocketman. I'll check and fill my transmission oil carefully, and monitor the level closely over the next couple of hundred miles to see if I'm losing any. If I learn that it is a leaky left seal, it'll be good to know that the left cylinder is smoking because of transmission oil seeping in, and that I'm not starving the right cylinder of injection oil.

Also, I'm interested to see if you guys have actually checked the injection oil consumption rate. I monitored my gas use closely, and measured how much injection oil I was using from the oil tank. The ratio came to 19.5 to 1. I'm wondering if that's right, to rich, or to lean for an overall average, and if I should make any adjustments to the oil pump cable. I set it as instructed in the manual.

Gary

[rocketman]

Oil ratio recommended by Bridgestone is 15:1 for break in and 20:1 afterward. So at 19:1,you are a little rich. I can't see it hurting anything. Plugs might foul out a tiny bit faster. The type and grade of mixing/injection oil can affect this slightly. By the way,theres a lot of talk about oils,smokeless synthetics vs castors/bean oils. I like two stroke smoke,even though the synthetics might be the way to go now. Espescially if you like riding with a group. Mark.

[rocketman]

I don't want to overload your plate with salad but,don't pass over the plug reading. Make sure there is in fact some browning of the electrode on the right side. Even though we're putting the leaky seal concern forward,there may be other components of the injection system to examine,like a clogged or sticky check valve which might create oil starvation. Also here's something to consider,before you decide you're new seal is actually faulty. Look carefully at the crank. Often a new seal will not seal to the crankshaft surface due to the old wear pattern of the previous seal. In this case you can usually space the seal away from the worn area of the crank. A couple quick ways of doing this is to shim the seal outward with the correct inner/outer diameter shims,(can't touch the crank), or make your own spacer from gasket material to move it out. You can simply "set" the seal without driving it all the way to the seat,(if there is one),but with nothing behind it,it may move on you. Sometimes depending on the dimensions of the seal itself,you can move it inward by cutting the thickness of the seating edge of the seal down. This can be a little trickier than going outward with it. Again some seals do not seat against anything and you just set them where you want them. If you do elect to re-position the seal,make sure it doesn't cause the seal to interfere with any of the other components,like the pump gear in this case.  Mark.

[v330123]

Thanks again Mark. Hope to check the plugs this weekend.

Gary

[rocketman]

Just checking up. Did you figure out where the smokes coming from? Mark.

[v330123]

Hey Mark,

Sorry I didn't reply earlier, but I haven't followed this email string for a while. I didn't realize that anyone was still interested, I'm glad you are, thanks for that. Anyway, I haven't done much more. First, I drained the transmission oil to check if any was gone. I put 26 oz in initially, and got back 24. So, I figure some might be in the pump drive, and some just sticks to the transmission components. I put in another 26 oz of fresh oil, and plan to ride for about 500 miles before I drain it again. That will take a while. I figure that if I'm losing oil from the transmission, then it's likely going through the pump drive seal into the left crankshaft. Sound reasonable? Remember, the left side is smoking more than the right side.

I've put a little over 500 miles so far since getting the bike back on the road. It runs so good at all speeds, starts first kick every time, idles very nicely, and hasn't fouled any plugs for the 500+ miles so far. This is not all my doing, I just bolted together the new parts. I think I'm just lucky with this thing. While I'm having this much luck, and fun, I hate to full with it too much. I am getting some smoke out of the right pipe, just not as much as the left. I'm not fearing, too much, that either cylinder is starving for oil.

I told you that I'd check the plugs, I haven't even done that yet. I'll do it soon and let you know what I see.

Gary