P200 bogging/too rich? issues
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Hooked
1979 P200E
Joined: 01 Jan 2018
Posts: 102
Location: Houston
Wed Aug 07, 2019 1:11 pm quote
I'm having some weird symptoms as of late. When it sits for a few hours or overnight, the gas lined doesn't seem primed any more. It takes about 3 kicks to start which I know isn't too bad, but the first 2 are totally dead dry kicks like it isn't even trying. About half way into the third, I feel it pop real strong like the fuel primed and it starts immediately. Then push in the choke and it seems fine. However, after it warms up, if I idle at a red light for a little too long, it'll bog kinda hard on first pull for just a sec. And then it'll catch up and ride just fine after that. Also, after it warms up, if I park it and cut if off for about 30 min, it'll be real hard to start like it's flooded. It's not really, really bad, like I don't have to lean it to get it going, but it takes a good 6-8 kicks and pulling the throttle to get it going again. But again, if I let it sit for much longer, I think the excess fuel drains/dries up and it'll start like I explained above. Thoughts?

Octo
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 1363
Location: London UK
Wed Aug 07, 2019 6:37 pm quote
Clutch side oil seal worn out?
Hooked
1979 P200E
Joined: 01 Jan 2018
Posts: 102
Location: Houston
Thu Aug 08, 2019 7:13 am quote
I did a rebuild only about 1100 miles ago and that included new seals. I suppose the seal could be faulty. What's the best way to check?
Enthusiast
GS150, LI200, TX200, PX125, T5200, SX200, PX125 CUTDOWN
Joined: 31 Jul 2019
Posts: 54
Location: South West England
Thu Aug 08, 2019 8:13 am quote
any traces of gear oil on inside rear tyre?
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 1363
Location: London UK
Thu Aug 08, 2019 7:10 pm quote
Crankcase pressure test is the best way.

When the seal leaks (or case gasket) the gear oil is always affected. The level goes up or down. If you drain the oil and see what it looks like and how much there is, should give you some idea . If ok re fill it, then check the level a few times before riding over a week. If the level hasn't changed in a few hundred miles the seal is most likely good enough.

As you have rebuilt it only 1100 miles ago the oil level should be exactly the same as the day it was done.
Veni, Vidi, Posti
74 50s x2 78 P200 84 Cosa 58 AllState 68 Sprint 80 50special + projects
Joined: 22 Nov 2010
Posts: 6996
Location: seattle/athens
Thu Aug 08, 2019 10:17 pm quote
Jack: Having an easy way to confirm that my seals are good appeals to me. Looking for signs of oil behind the flywheel & stator for the flyside seal, and at the rear wheel & hub for the rear hub seal is easy enough to know if there's a serious problem, but not so easy w/ that clutch side seal. What about a hose on a fitting into the clutch cover vent hole to see if the clutch/gear box side holds modest pressure? Worth a shot? What would be an appropriate pressure?
Jack221 wrote:
Crankcase pressure test is the best way.
...
edit: To be clear, because I've never done it, you mean pressure into sparkplug hole w/ blocked off exhaust and intake? What pressure held for how long?
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 1363
Location: London UK
Fri Aug 09, 2019 12:50 am quote
blow job
The clutch vent does seem like a good idea for a pressure test with least faff but quite easy to do more damage as pumping against the seal. On the old Vespas with outside main seal it's not such a risk but would be interesting to know what pressure a PX seal would pop out at.

A pipe on a fitting at the clutch breather (or oil filler with breather covered) would be a worthy test to check a really bad seal. Just blow in it with your mouth. If the seal was torn or missing, you would hear hissing at the carb.
Ossessionato
1976 Super (x 2), 1974 Primavera (x 2), 2006 Fly 150
Joined: 26 Sep 2013
Posts: 4761
Location: So Cal
Fri Aug 09, 2019 5:24 am quote
Hat tip to blackbart. Length of fuel line attached to 7mm fitting screwed into clutch breather hole

Quote:
The balloon in the picture above stayed inflated probably 15 minutes before I removed it
Hooked
1979 P200E
Joined: 01 Jan 2018
Posts: 102
Location: Houston
Fri Aug 09, 2019 6:26 am quote
I'm in the middle of a move right now so unfortunately I've been too busy to take a look yet.

I did change the oil few times already to keep a good eye on it and it never seemed to be too much or too little. I didn't really measure it though; was just eye-balling it.

Cool idea with the balloon trick. Will give it a go after settling in to my new place.
Veni, Vidi, Posti
74 50s x2 78 P200 84 Cosa 58 AllState 68 Sprint 80 50special + projects
Joined: 22 Nov 2010
Posts: 6996
Location: seattle/athens
Fri Aug 09, 2019 10:10 am quote
SoCalGuy wrote:
Hat tip to blackbart. Length of fuel line attached to 7mm fitting screwed into clutch breather hole
Quote:
The balloon in the picture above stayed inflated probably 15 minutes before I removed it
Thanks Mike, I missed that. The balloon makes perfect sense plus should be much easier than testing from the crankcase side.
Ossessionato
1976 Super (x 2), 1974 Primavera (x 2), 2006 Fly 150
Joined: 26 Sep 2013
Posts: 4761
Location: So Cal
Fri Aug 09, 2019 10:43 am quote
Yeah, blackbart is one crafty dude.

Thatís actually a pretty demanding test - it pressurizes the whole gearbox ... clutch seal, clutch cover o-rings, rear hub seal, the kick start seal, the selector box gasket, the main case gasket - even the oil fill and drain bolts (and the auto lube spindle if you have autolube). Iím surprised his engine held for 15 minutes. I donít think my engines would pass. Let us know how yours do.
Veni, Vidi, Posti
74 50s x2 78 P200 84 Cosa 58 AllState 68 Sprint 80 50special + projects
Joined: 22 Nov 2010
Posts: 6996
Location: seattle/athens
Fri Aug 09, 2019 3:57 pm quote
Add a worn batwing shaft to your list of things this thing should be able to detect. If the balloon goes down you'll still need to figure out where it's leaking but now we have a list of suspects.

Actually I have most of it already, just need to add the ballon. When I tried it a few years ago, I did as Jack suggested and it seemed to hold my lung pressure OK, but hard to know the leakdown like a balloon will show. I'd like this thing to 'find' a known bad clutchside seal to know it can be trusted. Will keep you posted

clutch vent test.jpg
fitting complete w/ o-ring is from a damaged vent assembly - just remove the cap

Molto Verboso
BV200, P200E (2),V90 and now a Big Ruckus
Joined: 07 Aug 2010
Posts: 1609
Location: Mims, Florida USA
Sat Aug 10, 2019 4:43 am quote
Make sure your choke is fully open and not sticking. Happened once to mine. Same symptoms
Hooked
1979 P200E
Joined: 01 Jan 2018
Posts: 102
Location: Houston
Tue Aug 20, 2019 6:44 pm quote
Hey again. Was out of town for work stuff. And like I said I also had to move. Things have been crazy lately. Anyway, just now getting to post an update. I see oil drips after letting it sit a few days. Also some on the rear wheel. I drained the oil and measured it as well: about 180ml. Seems low. I'm pretty sure there's no gas based on comparing the viscosity against new oil and because it doesn't really smell like gas. Haven't gotten to do a pressure test yet as my new garage is a total disaster at the moment. Few pics for your perusal:

octo

IMG_20190811_212607.jpg
oil drips

IMG_20190811_212617.jpg
spots on tire

IMG_20190811_212932.jpg
bonus neighborhood cat at my new place. name's tyler. he's very adventurous and vocal

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