New gz250, need help! - Page 2

lowbeam · 11-06-2017, 10:59 PM

To anyone interested: pod filter is on(52mm, a 50mm would probably fit as well), open exhaust, 140 main jet and the washer from the needle switched to the other side of the clip. Pilot screw is turned all the way out and it pulls good at higher rpm now. Idle is still just okay. I might put in a bigger pilot jet but I am not sure how restrictive the screw needle is. I am thinking of sizing up the pilot jet and shimming the needle with another washer to smooth everything out but it is running pretty well as is. Need to check for any leaks in case that is my problem and figure out a mount for the battery other than the zipties I have around it as the battery rests against the air box which I don't have on my bike anymore.

kilo0195 · 11-08-2017, 11:26 PM

I think the "hole" you were speaking of is the one that keeps the carb from outright flooding if the float valve fails... no problem there. I would also hold off on changing the pilot jet. I have seriously modded my bike (300cc kit, decked, ported, etc) and I run the same size pilot jet, a 70 mid jet, and 147.5 main. I just foresee a larger pilot making things far too rich.

lowbeam · 11-10-2017, 05:47 PM

Quote:

Originally Posted by kilo0195

I think the "hole" you were speaking of is the one that keeps the carb from outright flooding if the float valve fails... no problem there. I would also hold off on changing the pilot jet. I have seriously modded my bike (300cc kit, decked, ported, etc) and I run the same size pilot jet, a 70 mid jet, and 147.5 main. I just foresee a larger pilot making things far too rich.

Thanks for the advice! What does the mid jet control? The diagram that I have from the manual says there is a pilot jet, main jet, and starter jet. I thought that the starter jet was just for the choke.

How do you have your crankcase breather set up? Right now mine is just the line open which obviously I need at the least a filter for it.

I started the bike up again today after going over everything again. The pilot screw was leaking a little fuel onto the bit when I was adjusting it so I pulled it apart and the o ring and washer were flipped. I am not sure if I was able to seat them back correctly as there is a slight vacuum when I hold my finger over the tube. I plugged the tube it sits in for now until I can get a new o ring small enough to try to seal it again. Somewhere else there is still a vacuum leak and there is an audible noise of leaking air. Is it possible for the choke plunger to leak around the cable? Not the metal bit with the o ring because that is new but the cable itself and the elbow or through the cable shield? The carb boot is tight to the head and not ripped, I am going to try to wrap some electrical tape around the clamp to get it even tighter than it already is because I ran out of adjustment tightening it. I might get a new carb boot and a new carb soon because I am losing patience with such a simple problem

I will see if i can get a video today of it running and post it here to see if anyone has any ideas!

lowbeam · 11-10-2017, 08:48 PM

Alright so I used a new hose clamp instead of the tape.. still get the same noise. I never noticed it before I put the pod filter on but after watching the video it sounds more like it is leaking from the head side of the boot. I will order a new one but in the time being I am going to try to seal it with some gasket maker. The bolts are already over torqued. I didn't open the throttle in the video but when i did it would hang up and slowly come back down. When I sealed the hole I was talking about previously it would stall unlike before it would stay running which does not make sense to me but I now think its an air vent so the gas can be sucked through the jets if that makes sense.

Excuse everything being a mess right now lol https://vimeo.com/242326675

I also noticed that it was idling fine and my neutral light was off with it obviously in neutral. A minute later the light came on and the idle started to creep up. Probably a coincidence but I need to look into the neutral issue.

lowbeam · 11-16-2017, 06:36 PM

If anyone was following this I finally figured out the issue. The choke plunger and its seat were dirty and sticking half open or not sealing properly. It seemed like it was slowly leaking and then letting a drop of fuel leak into the engine and causing a small vacuum leak at the same time. I polished up the plunger and cleaned where it sits with a carb cleaner and a q tip and cleaned and lubed up the spring and holder and the bike is idling consistently and running good now. I still have to dial in the idle mixture when its hot as it bogs slightly when I give it some throttle.

11-06-2017, 10:59 PM	#11
lowbeam Junior Member Join Date: Oct 2017 Posts: 10	To anyone interested: pod filter is on(52mm, a 50mm would probably fit as well), open exhaust, 140 main jet and the washer from the needle switched to the other side of the clip. Pilot screw is turned all the way out and it pulls good at higher rpm now. Idle is still just okay. I might put in a bigger pilot jet but I am not sure how restrictive the screw needle is. I am thinking of sizing up the pilot jet and shimming the needle with another washer to smooth everything out but it is running pretty well as is. Need to check for any leaks in case that is my problem and figure out a mount for the battery other than the zipties I have around it as the battery rests against the air box which I don't have on my bike anymore. Login or Register to Remove Ads
	0

11-16-2017, 06:36 PM	#15
lowbeam Junior Member Join Date: Oct 2017 Posts: 10	If anyone was following this I finally figured out the issue. The choke plunger and its seat were dirty and sticking half open or not sealing properly. It seemed like it was slowly leaking and then letting a drop of fuel leak into the engine and causing a small vacuum leak at the same time. I polished up the plunger and cleaned where it sits with a carb cleaner and a q tip and cleaned and lubed up the spring and holder and the bike is idling consistently and running good now. I still have to dial in the idle mixture when its hot as it bogs slightly when I give it some throttle. Login or Register to Remove Ads
	2

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

11-08-2017, 11:26 PM	#12
kilo0195 Member Join Date: Jul 2017 Location: Illinois Posts: 52	I think the "hole" you were speaking of is the one that keeps the carb from outright flooding if the float valve fails... no problem there. I would also hold off on changing the pilot jet. I have seriously modded my bike (300cc kit, decked, ported, etc) and I run the same size pilot jet, a 70 mid jet, and 147.5 main. I just foresee a larger pilot making things far too rich.
	0

11-10-2017, 08:48 PM	#14
lowbeam Junior Member Join Date: Oct 2017 Posts: 10	Alright so I used a new hose clamp instead of the tape.. still get the same noise. I never noticed it before I put the pod filter on but after watching the video it sounds more like it is leaking from the head side of the boot. I will order a new one but in the time being I am going to try to seal it with some gasket maker. The bolts are already over torqued. I didn't open the throttle in the video but when i did it would hang up and slowly come back down. When I sealed the hole I was talking about previously it would stall unlike before it would stay running which does not make sense to me but I now think its an air vent so the gas can be sucked through the jets if that makes sense. Excuse everything being a mess right now lol https://vimeo.com/242326675 I also noticed that it was idling fine and my neutral light was off with it obviously in neutral. A minute later the light came on and the idle started to creep up. Probably a coincidence but I need to look into the neutral issue.
	0