|
|
Post by sweden on Aug 18, 2010 12:35:26 GMT -5
OK, I am getting to the point where I going to have to give some mega expensive swedish mechanic my hard earned greens....well, blues here....in more ways than money!!  My 139 QMB 50cc is still having bogging issues, when I open the throttle fully, it dies and I have to close it down and open it again to keep it running. So far I have: Installed a new air filter and air intake pipe and played with the AF adjustment...still the same. Adjusted the valves and played with the AF adjustment, still the same. Adjusted the valves a second time...guess what? Still the same Removed the carb, stripped it, cleaned it as per the Big Guys Carb cleaning video (great video, I learnt alot there) replaced it, got it started, took it out and warmed it up and tried the AF adjustments and the bogging was still there. What can I try before admitting defeat now? I would love to fix it myself, so I don't feel beaten by a scooter engine and pay out silly money for something that might be stupid. Could it be plug failiure or not enough fuel getting through for the demand or something more sinister like the piston being knackered? Thanks again folks, I hope you aren't getting fed up with my continual shouts for help and advice!!!!! |
|
|
|
Post by Enviromoto on Aug 18, 2010 12:40:25 GMT -5
Have you checked your vacuum petcock? If its going bad it will starve your engine for fuel in the higher rpms.
|
|
|
|
Post by sweden on Aug 18, 2010 12:46:05 GMT -5
You know I just sat down and thought petcock....not really sure why? How do I check it to see if it is working right?
|
|
|
|
Post by rgdroid on Aug 18, 2010 13:19:56 GMT -5
Easiest way I've found is to disconnect the fuel line just above the fuel filter, then disconnect the vaccum hose at the intake manifold. Suck on the vaccum line and if fuel comes out of the fuel line then its working properly. If little to no fuel comes out when doing that then its not.
|
|
|
|
Post by sweden on Aug 18, 2010 13:26:16 GMT -5
Sounds like another case of....follow procedure with more red wine!! ;D
I will give it a go.
|
|
|
|
Post by rgdroid on Aug 18, 2010 14:18:05 GMT -5
Haha, I don't think you should have much of a gas taste in your mouth. At least I didn't. ^^
|
|
|
|
Post by rgdroid on Aug 18, 2010 14:22:10 GMT -5
By the way, if your still bogging down that would mean your too rich. If its backfiring your too lean. I'd really want to say its a a/f mixture issue.
|
|
|
|
Post by sweden on Aug 19, 2010 0:35:16 GMT -5
By the way, if your still bogging down that would mean your too rich. If its backfiring your too lean. I'd really want to say its a a/f mixture issue. No backfiring at all.....I wish it was a AF mixture issue but I swear that I have had that screw in every possible position and it makes little if no difference, I tried with the two turn out, tested, adjusted in 1/4 turns and nothing has made any difference......I go have the cleanest carb in Gothenburg now though! |
|
|
|
Post by relaxinrob on Aug 19, 2010 8:26:37 GMT -5
I am having the exact same problem and have done everything you have. I have even taken the variator off and cleaned it. It is very frustrating. Let us know if you solve this. I will also.
|
|
|
|
Post by thedirtypickle on Aug 19, 2010 9:08:50 GMT -5
my buddy had some of these symptoms and we fixed it by cleaning the carb (you did this). We found that the pilot jet was a little gummed, but the thing that I think was the prob was that the gasket was not completely in it home.
The carb gasket for the fuel bowl. if it does not sit nicely in its grooves then start there. That will cause all sorts of goofyness.
|
|
|
|
Post by sweden on Aug 19, 2010 9:21:27 GMT -5
I am having the exact same problem and have done everything you have. I have even taken the variator off and cleaned it. It is very frustrating. Let us know if you solve this. I will also. Of course, as soon as I find the problem, I will spread it here. I am going to check the petcock tonight as suggested and drink some petrol. I have stripped and cleaned my carb and the only thing I am concerned about there is that the diaphragm didn't sit tightly like it did in the big guys video, anyone think that could be an issue? |
|
|
|
Post by redwolf on Aug 19, 2010 9:39:08 GMT -5
::)did u try a new gas filter  |
|
|
|
Post by redwolf on Aug 19, 2010 9:42:02 GMT -5
p.s. where do i find the Big Guys Carb cleaning video ?
|
|
|
|
Post by sweden on Aug 19, 2010 10:59:49 GMT -5
p.s. where do i find the Big Guys Carb cleaning video ? Here you go...it is very good. www.vimeo.com/6519657Not tried the gas filter, will take it off when I do the petcock test tonight and see how it looks. |
|
|
|
Post by sweden on Aug 19, 2010 11:20:19 GMT -5
Ok, I have tested the petcock now and that is working just fine, I didn't get any taste of petrol in my mouth but am having the red wine anyway!!!! (Oh and the gas filter was fine too)
What should I try next? Someone mentioned the CDI unit, is that a possibility?
|
|
|
|
Post by relaxinrob on Aug 19, 2010 15:31:17 GMT -5
on mine, i put a new carb on, a new cdi, a new coil, a new plug, a new fuel line and filter.....adjusted the carb many times per instructions, set the valves to .004, pulled the variator and checked the weights.....none of this has helped..
|
|
|
|
Post by als01seville on Aug 19, 2010 21:44:41 GMT -5
Ok, if your carb has a butterfly then just cleaning out the jets is not good enough. Inside the intake by the Butterfly are fuel passages for the Pilot jet if those are clogged and the jet is clean its not going to help. Get Carb Cleaner or Can of Air they come with a long thin straws. Spray the Carb Cleaner into the Pilot Jet hole and you should see it coming out by the Butterfly Holes. That is probably why adjusting your air/fuel mixture is doing nothing when turning it everywhich way. Here is a picture I took and marked with red dots to show where the tiny holes are by the Butterfly. Thats how Your Idle Speed screw makes your idle either go up or down. By closing the Butterfly LESS Pilot Fuel Passages are exposed and therefore lower Idle, when you turn the Idle SPeed screw Clockwise it opens the Butterfly and EXPOSES MORE Pilot Fuel Passages therefore your RPMS go up. Give it a try it may solve your problem. And contrary to what everyone says your Pilot Fuel Passages feed fuel throughout your RPM range. Alleyoop  |
|
|
|
Post by Steven Spielburgman on Aug 19, 2010 23:09:52 GMT -5
Does Volvo make scooters?
|
|
|
|
Post by sweden on Aug 20, 2010 0:32:40 GMT -5
Does Volvo make scooters? No, just very boring cars, all made here in Gothenburg (Göteborg)!  als01seville, thank you for that, I did completely strip my carb and sprayed a good 1/2 can of cleaner into every single part of the carb and down every hole, I shall take the carb off again and check those holes though, just to be sure. Could it be a bad diaphragm in the carb, it looks fine but doesn't sit tight, I mean it lifts straight out without having to work it out? |
|
|
|
Post by Steven Spielburgman on Aug 20, 2010 1:05:25 GMT -5
Sell it to a Dane
|
|
|
|
Post by sweden on Aug 20, 2010 7:11:52 GMT -5
Yeah...that will sort my problem!  |
|
|
|
Post by Steven Spielburgman on Aug 22, 2010 19:40:11 GMT -5
|
|
