"Mercedes Streeter" (smart)
12/24/2018 at 15:59 • Filed to: wrenching, Two Wheels Good
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"Mercedes Streeter" (smart)
12/24/2018 at 15:59 • Filed to: wrenching, Two Wheels Good | 1
| 11 |
Good, bad, and very ugly... :/
The good:
- Engine now starts, stops, and restarts as normal. Prior to today (but after the initial death of the scooter) if you ran the engine then shut it down, it will not start again until cold. I think this had something to do with the carb being fouled by that rusty fuel filter and the bad gas I ran through it when I first got the scooter.
- Radiator fan works. This scooter runs really cool, but running it on high RPM sitting still finally warmed it up enough to warrant the radiator. Good on CF Moto for making a competent cooling system.
- Replaced all fuel lines, fuel filter, and carb. Decided to use clear lines so I can see what’s coming out of the tank. Nice and clean.
- Dumped the old air system for a pod filter. No more sucking up the garbage from the crank breather and no more having to take apart the whole rear of the scooter just to change an air filter.
The bad:
- Top speed is 40. I assume this is because of the pod filter. I’m going to start restricting the filter and see how that changes the engine behaviour. I know the proper thing to do is rejet, but you know me... ;)
- Lots of gray smoke. I think this is also related to a poor air/fuel mix.
The very ugly:
- White smoke billows out of the crank breather at high RPM. I have no idea if this is related to our aforementioned pod filter or if that’s just normal?
- The milky mocha coloured oil is coming directly out of the crank breather. I’m not sure if that’s normal? The oil in the engine is clean, how in the world is it milky coming out of the breather? At any rate, I ran the engine at high RPM for a couple minutes and after a while both the white smoke and the milk stopped. I’ve read on other forums that a lot of milky oil is a mix of too much oil in the engine plus condensation, no idea how much weight that actually holds.
Anything I should be watching out for?
Future Heap Owner
> Mercedes Streeter
12/24/2018 at 16:10 |
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Is it possible it’s getting frothed up in the breather? That would explain milkiness, right?
TheRealBicycleBuck
> Future Heap Owner
12/24/2018 at 16:13 |
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Exactly what I was going to suggest. That’s an indication that it’s over-filled. An over-filled crank case is what killed my WRX.
Spamfeller Loves Nazi Clicks
> Mercedes Streeter
12/24/2018 at 16:20 |
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Breather is frothing with a lot of condensation. Need to find the source of the condensation. Most pod filters are garbage that let a ton of liquid in while also contributing liquid themselves. Which could very easily be your gray smoke.
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Future Heap Owner
> TheRealBicycleBuck
12/24/2018 at 16:23 |
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Hey, look at that, it’s almost like I know things!
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Mercedes Streeter
> Spamfeller Loves Nazi Clicks
12/24/2018 at 16:27 |
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Thankfully the pod filter is in an entirely different location than the crank breather. The crank breather is attached to the airbox in the back of the scooter that now serves no purpose. The pod filter is chilling out with the carburetor. The filter offers absolutely no backpressure so I’m going to restrict it until the engine runs smoothly.
If I had to hazard a guess, the condensation is coming from the winter environment and my very short rides to work.
Looks like the easiest solution to the spewing of the oil anyway is to run the engine at slightly less oil than specified. That would just leave the breather smoke as my concern.
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Mercedes Streeter
> TheRealBicycleBuck
12/24/2018 at 17:03 |
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I had a feeling the crank was too full. I was mostly alarmed at the consistency of it. Good to know nothing catastrophic is happening. Guess this is the end of riding the scoot to work. Clearly 1 mile rides aren't enough to keep condensation from building.
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TheRealBicycleBuck
> Mercedes Streeter
12/24/2018 at 17:58 |
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It’s not about the moisture. When the crank case is too full, the crank acts like an eggbeater and whips a bunch of air into the oil. Once it’s full of air, the pump can’t pump the oil and the engine craters due to oil starvation. This is what happened to my WRX. I took it in for an oil change and they put in roughly twice as much oil as it was supposed to get. No one admitted it, but I think someone auto-filled it with the pump, got distracted, couldn’t remember filling it, then auto-filled it again without checking.
I would look up the manufacturer’s specs on how much oil is supposed to be in the crank case, drain what’s in there, then refill it with the correct amount.
Dr. Zoidberg - RIP Oppo
> Mercedes Streeter
12/24/2018 at 19:17 |
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“Top speed is 40"
Meh! Not bad.
- guy who owned three Tercels
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Dr. Zoidberg - RIP Oppo
> Future Heap Owner
12/24/2018 at 19:18 |
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Whoa, whoa, whoa. Whoa. What?!?!
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Spamfeller Loves Nazi Clicks
> Mercedes Streeter
12/24/2018 at 20:17 |
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If you’re not getting up to running temp, you’re gonna have condensation problems regardless of how much oil is in the crankcase. This goes double for carb’d four-strokes. You could very well have the correct level of oil in the crankcase, but because it’s thicker than normal, the poor flow acts symptomatic.
Cold damp air, of course, also doesn’t help. Gray smoke basically you’re talking oil mixed with water, NOT coolant. VERY IMPORTANT DIFFERENCE! It’s clean water rather than glycol which tells me it’s exterior intrusion into the intake path. (Because if you were running distilled, you’d have a dead bike, duh.) Probably also dealing with fucking Ethanol smoking. There’s a REASON I hate goddamn boiled corn in my gas. >:|
I don’t believe the crankcase is overfull, and it’s not a good idea to run low. There’s got to be an issue with the breather, because otherwise, it wouldn’t spit oil. As I mentioned, cold temps plus not getting the engine warm, not a good combination. So my first suggestion would just be changing the oil. If you run 10W30, switch to 5W30 or even 5W20.
I’d also check the coolant temp a little more closely. Could be a bad thermostat which is not letting the engine warm up. Too cold == bad. That will also contribute to your gray smoke because if the engine is too cold, the spark plugs aren’t working right, leaving you with incomplete or cold combustion. Running the engine colder is RARELY better unless you really know what you’re tuning. And it requires changing a literal pile of parts to accommodate it. It may also be that the thermostat specified from the factory is just too low for cold weather running. It wouldn’t surprise me if somebody put a super cold tstat in a bike just because they don’t think anyone would use it when it’s 30F out.
With the air colder, you also have significantly increased air density. So if you rejet at 30F, it’s going to be dangerously lean at 60F, quadruple that with a cold running engine. (Yay square law.)
So, basically, swap your normal temperature stuff for cold temperature stuff, see if that improves. Meaning go down colder on the oil and spark plugs . If the oil doesn’t help, it won’t hurt, and you can always swap back the plugs if there’s no improvement.
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Mercedes Streeter
> Spamfeller Loves Nazi Clicks
12/25/2018 at 01:44 |
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This has been massively informative!!!
Someone on a dedicated motorcycle forum suggested letting it run at a mid-ish RPM at running temp for a while to burn built up condensation . I put it on the center stand with just enough throttle to make the crank vent oil. Took about 15 minutes of running at running temp then it stopped venting oil and the smoke went down to a minimum. This scooter smokes a little when the air/fuel mix is off, so I think once I straighten that out I should be good. The pod filter is way too free-flowing. I hope when I'm done it'll run better than ever. No more rusty fuel, no more oil fouled filters, and hopefully I can hit that mythical 80 mph.
In the time I’ve been riding the scoot I’ve maybe gotten it to full running temp twice... the day I first got it running and the day it died again. That leaves me with a lot of days of just riding a mile or two and calling it a day.
I think I’ll switch to the 150 GY6 for the work commute and instead keep this for longer winter rides.