Page 1 of 1

Help!! I think I killed it!!!

Posted: Wed Aug 06, 2008 12:14 am
by hotlantan
Hello, all. I have an 86 Spree and I recently changed out my rear brake pads and didn't tighten down the nuts at the exhaust port enough and the pipe got a little loose. I thought that it was a small leak and wouldn't amount to any more back pressure loss than drilling the muffler, but now the engine wont turn over completely. It turns until it approaches tdc but then gets stuck. I can turn it by hand, so it's not completely seized, but it won't turn over.
Also, I lost the air screw about two weeks ago, and I just ran without it thinking that I would just be running rich. Did I have that backwards and I was running lean and melted something? Right up until maybe fifteen minutes before failure it was running fine, then I hit a big bump and it died. I took off the panel and saw that my sparkplug wire had come loose and I reattached it and it would run fine for a while and the it would come off again, and I'd put it back on and it would run fine. this went on for about another 4 or 5 times before I couldn't get the kickstart to budge.
When I got home I pulled the plug and the gap had completely closed. the kickstart itself was fine.
Anyone have a clue as to what might be going on? Thanks in advance for any help.

Posted: Wed Aug 06, 2008 1:19 am
by Kenny_McCormic
Missing airscrew will cause lean running, as will a loose exhaust.

Posted: Wed Aug 06, 2008 10:05 am
by noiseguy
You seriously ran the scooter like that and thought that would be OK? Yes, you hosed the engine. You probably need a new piston and jug now.

Posted: Sun Aug 17, 2008 8:06 am
by hotlantan
Kenny_McCormic wrote:Missing airscrew will cause lean running, as will a loose exhaust.
How does the exhaust leak cause lean out? I thought it could possibly throw the timing but I didn't think it would be any worse than drilling the muffler like is suggested here. I realize that depending on how loose it was it could lose a lot of back pressure, but I wasn't aware that it could cause lean running.

Posted: Sun Aug 17, 2008 9:13 am
by mikehelms
hotlantan wrote:How does the exhaust leak cause lean out? I thought it could possibly throw the timing but I didn't think it would be any worse than drilling the muffler like is suggested here.
Any change to the "air pump" that affects airflow will likely affect the air/fuel mixture. Modifying the exhaust (or allowing manifold bolts to loosen :-) ) without changing the air/fuel mixture is a surefire recipe for a lean-mixture meltdown.

Pull your head off and see what the top of the piston looks like. You probably need a new piston and rings, and it sounds like you may need some new exhaust studs and bolts as well. Not the end of the world, but it should give you some pause next time the exhaust comes loose.

My stock Spree hits 35 on level surfaces ... how much faster do you want your weed eater to go? :-)

-- Mike