Help: Gio 125cc quit running

[awbrooke824]

I've had a few posts here where I've been fixing up a Gio 125cc. After replacing the stator with a performance stator, I've replace the spark plug with an NGK C7HSA (as per this forum and internet references) I bought from my local bike shop.

The bike has been running great. My nephews drove it around the hay field for hours. My son hopped on the bike today and in between shifting from 3rd to 4rth, the engine died.

I have spark on the spark plug, when holding it against the engine head. I've replaced the fuel line and there's plenty of fuel running through. I took the carb partially apart and it looks clean enough, mind you I'm not confident enough to do anything too major here.

When kicking slowly, the compression feels normal. I've squirted some gas into the piston and there's no response in the engine. The spark plug doesn't even look hardly wet. This concerns me ... no engine kick with fuel directly in the piston.

My fear is a pin hole in the piston, but I have no idea how to check that. Anyone have any other tests I might try?

Thanks.

[Cal25]

See if a local auto parts store loans tools and get a compression tester. The only other thing I can think of is maybe there was a little too much fuel in the cylinder and caused a flooded condition. You could try starting it with the choke off, and the throttle held open.

I bet it turns out to be something simple.

[mizke]

also check for loose electrical connections..

oh and it might be a good idea to pull the carb off and take the jets out and clean them... might have had some gunk in the bottem of the tank that broke loose or gunk in the fuel line that broke loose and clogged up the jets

[awbrooke824]

I went over all the wiring again, reconnected them all and I'm getting a strong spark, but still no life in the engine.

I had the carb off but I have no idea what to do with it. My neighbour does a lot of this sort of thing so I'll ask him to help with cleaning it. I've replaced fuel lines and the kids pretty much ran it out of gas, so maybe something has the carb plugged up. I find it odd that the plug never looks very wet, so the carb is definitely highly suspicious.

Good call on the compression test. I'll check around and see what I can get. I've had a blown piston in my ski-doo before and this just doesn't feel the same. But it doesn't take much to cause a problem.

Thanks for the ideas!

[Weldangrind]

Try another plug just for fun. They're cheap. A plug that sparks out of the hole won't necessarily behave under compression.

Try bump starting it. Push the bike with your son on it and the kill switch on. Once you're up to running speed, have him kick into second and dump the clutch. If it doesn't lock up, it should fire (assuming proper fuel, air and spark).

If there is a fuel flow problem, my guess is plastic crap from the tank. I'm thinking that because you indicated that the bike ran out of fuel. Do you use an inline filter? They're cheap, but find a US made filter.

[mizke]

auto parts stores should have some inline filters..

i use a clear cone shapped filter its a great little filter that every now and again i pull off and flush out with water then let it dry over night before using it again..

[Weldangrind]

Just make sure that it's not an offshore filter. I had one come apart; thankfully it happened after a ride and the fuel valve was shut off.

I can buy the US made filters here for around $4.00.

[katoranger]

. I'm thinking that because you indicated that the bike ran out of fuel. Do you use an inline filter? They're cheap, but find a US made filter.

Coming from a Canadian. :wink:

[awbrooke824]

The fuel filter I'm using did come from Gio. When I pull the line off the carb there's plenty of fuel flowing through. I had a another new from from Gio so I stuck it on but no luck. I'm going to buy another chunk of fuel line and hook it up without a filter just to rule it out. Also, I'll pick up a new plug while I'm at it.

Just to be sure, I'm using an NGK CR7HSA plug. Everything I've read indicates this is the replacement for the original A7RTC that I took out.

I'm getting my hands on a compression tester this weekend and will take apart and clean the carb as well. I appreciate all the input. I'll keep everyone posted on my progress .. or lack of.

[waynev]

Just to be sure, I'm using an NGK CR7HSA plug. Everything I've read indicates this is the replacement for the original A7RTC that I took out.



Yep that's the right plug, i too used that in my 125cc dirt bike, i also use that same plug in my 110cc T1 and 50cc mini ATV.

[awbrooke824]

Picked up a new fuel line, but that made no difference. Bought a can of Carb & Choke cleaner, completely dismantled and sprayed down the carb, re-installed it but not a bit of difference.

I did discover that the gas I drained out of the tank last night was a deep yellow colour. I didn't think much of it until I had a dish of gas from my own can and noticed that it's not yellow at all. Of course I've put clean gas into the Gio tank but I'm wondering if other bike parts could be gunked up.

The plug is snapping when I test it, the carb is clean, yet there's no life at all in the bike. I'm also wondering about the coil and whether or not it's delivering enough juice to the plug. Anyone know how to test the coil? What kind of voltage should I see from it?

I wasn't able to get a new plug, so I'll have to keep messing with the one I have. Dang ....

[waynev]

You by chance aren't pulling in the clutch when trying to start it are you?, it will only start in neutral with the clutch NOT depressed.

[mizke]

you could always do a compression check if you are worried about bad rings or a pin hole in the cylinder...

did you clean the jets ? you should remove then and hold them up to a light and check to make sure you can see through them

[awbrooke824]

No, not holding in clutch. It seems to kick over fine with good resistance ... haven't done the compression check yet.

I've cleaned the carb twice, checking all the jets and other bits to be sure they're clean and I can see through them. What seems to be the problem, based on the dry spark plug, is that gas isn't being drawn into the engine.

I'm about to surf around for ideas as to why the gas isn't being pulled into the cylinder. Maybe it is a compression issue that isn't able to create an appropriate amount of suction?

Being in Canada, I've found a web site called China Parts Canada. If there is a piston issue, I'm thinking I'll need the kit at http://chinapartscanada.com/shopping/shopexd.asp?id=372. The more I work on this the less I'm thinking it's the carb.

[waynev]

Take off the air filter, put your hand over the carb and then kick it over, if your hand doesn't get soaking wet then there is no fuel going thru the carb, i've never really seen this happen but also make sure the clip hasn't fallen of the jet needle and is stuck in the needle jet which would cut your fuel off.

[awbrooke824]

Bike is running again!

My neighbour, who tears down snowmobiles in the morning and then rebuilds for a drive in the afternoon, came over to take a look.

We played around with the compression, but this didn't seem to be of great concern to him. When checking the spark he didn't like the look of it, even though it was sparking like crazy. To him, the pattern looked erratic.

I took off the chain guard to inspect the performance stator that was added (see my other thread). As he was cleaning the fly wheel and tightening the nut, he noticed the nut had loosened enough to allow the fly wheel to jump off the shaft key slightly. The fly wheel was reassembled and tightened and the bike fired up in just a couple of kicks.

As I look over the symptoms, this make sense. With the fly wheel shifted so was the timing. The plug would fire and burn gas in the cylinder, thus the dry spark plug, but not fire at the right time to run the engine.

I've re-soldered all my connections and put the bike back together. With all the thorough carb cleaning I've done the bike is running like a million bucks.

I want to thank all who responded while I messed around with this. Someone right near the start of this thread said it would be something simple ... and sure enough it was. I'll add a note to my other thread to be sure others doing the stator update are sure to secure the nut. There must be a tool for grabbing onto the wheel while tightening.

My son is grinning from ear to ear tonight!

[FastDoc]

Wonderful news! Great neighbor!

[mizke]

awsome dude

might i make a suggestion tho... go over the important bolts, remove and then put some blue locktite on them, then reinstall..

when i first got my quad and got it running, i was riding in front of a friend and he noticed the rear tire on the right side about to fall off.. about a minute before that we were topping it out down a street.. had that have decided to come off at speed.. it would have been bad..

just remember incase you dont know this already

blue loctite = removable with a wrench
red loctite = removable with a torch

[Cal25]

Glad you got it running and on the cheap!