giantco sprint vil ikke starte

[emanuel]

Hi there,

I hope this isn't a problem but I can't speak danish. I speak a little but I can't really write more than basics in danish.
I have a problem with my scooter. I bought it from guldoggratis a year ago and I keep having probpems with it. From front break jamming in the middle of the intersection in the winter to getting stolen and now refusing to start.

Since the brake jammed ( after it got stolen) i had to buy a lot of plastics (which were ripped off) and a new breaking system (all) and I ended up buying a second one without a carburator.
I really need the scooter since i can't afford riding the bus and a knee injury doesn't allow me to takle the hills from Nordjylland.
I have been having problems with it starting on cold/rainy weather. I had the pipe which returned the exaust gasses in the admisssion broked and welded shut (by a local shop) and I thought that was the problem and I've changed it. No improvements in starting but runs nicer. I have cleaned the carburator in january-february and it was like new (actually I just took a look inside). I bouht a new battery.
The scoyer normally stays in the basement (heated) during the night and starts easily in the morning but if it rains and it stays outside for 4-5 hours I can't start it. Not by using the kickstarter or the el starter. Maybe after 10 minutes it starts for 2-3 seconds after I almost kill the kickstarter.
I think I still have compression since I can feel it oposing the kickstarter. If someone can help me I would be very grateful or if someone from Aalborg has time to have a look I can bring a beer but please don't send me to a shop since I'm a student..

Thanks.

[scootergrisen]

Its proberly an electrical problem why you cant start in rain.
I have also had problems in rain and its was because of bad connections.

So go trough all the connections and look for rust and green stuff like this and check these places and also the fuses.

[emanuel]

Thanks for the fast reply.
I will check that tomorrow altought it would be strange since I can use the electric starter (it spins) horn, signals and alarm. And it starts in the rain for as long as it didn't sit there for too much time. I had the same problwm last winter when I was leaving it out it the cold during lectures (8-9 hours) but then after 20 minutes of kickstarting it would start. Today i just gave up after 1 minute and pushed it in the basement.
I will look again at all the electric wires, redo the grounding wire since i changed it when I got it and try to find bad connections. also I will try to change the cdi and look at the sparkplug since I have never checked it but when it runs it it runs nicely 50km/h with limited cdi

[onkelroar]

Try cheking the earthing connection to.

It´s a problem witk thoose scooters. Try adding an extra earthing cable from the battery (minus) to the engine.

[emanuel]

sorry for comming back so late.
i had checked all the connections and all of them were ok. i already have an extra ground wire.
the probpem was the sparkplug cap. it was alsost taken off, so when it rained it would discarged into the case. pushed it back and it starts instantly.
now I scared I might need to change the piston since last night after leaving the scooter in the cold and damp weather for 12 hours it wouldn't run. it started at the first try but when it started to move it would make a strange noine and not accelerate at all. strangelly, once it get going it would not stop....
i will put a recording so maybe you guys know better, and I'll also check to see the carburator.
how complicated would it be to change the piston? i have previously changed the timming chain on cars but there I knew where everything is and how to rearange the timming. do I need any special tools? i have keys and rances to open the entire motor. hope I didn't bother you too much and thanks for the electrical hint, I would of never figure it out and I was ready to take the motor appart.

[Baddi]

Changing the piston is not too difficult, but it can be an operation witch need you to know what you do.
- Fist, buy all the sealing gasghets need, as theese should be changed every time you open the engine. Also make sure that you have some cloth to put the engine parts on so they won't get dirty. Also have som cloth to put around the rod.
- Then, remove the black plastic, the chain tensioner, the rocker arms, and the camshaft, but make sure that the cam chain wont fall down into the engine.
- Then remove the two brass (i think) bolts on the side of the cylinder that holds the cylinder head and cylinder to the engine and while still holding on the the cam chain, remove the cylinder head and gasghet. Now you should be able to see the top of the piston, and it is probably all black and sooty.
- While still making sure that the cam chain does not fall into the engine, remove the upper cam chain guide and the cylinder. As soon as the cam chain can be placed in a resting position without falling into the engine, use one of your hands to hold beneath the piston to make sure that it won't fall anywere when it is fully exposed.
- When it is fully exposed, put some cloth around the rod beneath the piston and in the cam chain hole to prevent things from falling down there.
- With a pointy plier, remove the little clips holding the metal part connecting the piston to the rod, so you can remove this and remove the piston.
- Change gasghet on the bottom of the cylinder before assembling in reverse order. If you need to force it when assemling, somthing is wrong, so use alot of motor oil (2-stroke oil prefered) so it glides easily, but this will make alot of smoke on initial startup, so when the piston and cylinder are in place, turn the crankshaft (while holding on to the chain) until the piston are at top dead center and then wipe off the excess oil.
- put in a new top gasghet and assemble the top. Remember to cross-tension every bolt and nut, so the tension are equal. If you have one, use a momentum-key to tension these, so it wont get too much.
- Remember to get the cam timing right and then put the valve cover and the plastics back on.

[emanuel]

while most of what you said I understood. My problem is visualization on the motor.
I don't know where the tensioner is and all the other stuff you've talked about.
Do you by any chance have a tutorial with pictures arround here?

I'm not sure that it's the compression since on most cars that I drove, when the compression/timing was bad you would get a lot of smoke and the motor won't start easily. Mine starts instantly it revs while I keep the break on and I can barelly hold it, but as soon as it moves it starts to make a strange noise and not move. It's like it's miss firing the spark. I can put a recording here .

[Baddi]

Great!
There are a tutorial in english Here.

[Baddi]

And remember to reset the chain tensioner as shown here

[emanuel]

here are the 2 recordings where I tried to catch that strange sound. It's very strange that it starts prefectly, idles prefecty, it pusshes very hard when the break is on, but at soon as I let go it becomes retarded.