Go Back   GZ 250 Forums > GZ250-Specific > Troubleshooting

Reply
 
Thread Tools Display Modes
Old 05-20-2017, 04:12 PM   #1
justincan423
Junior Member
 
Join Date: Mar 2017
Posts: 6
Bike dies when throttle engaged

So I recently bought a 2000 GZ and I'm not very knowledgeable in the motorcycle field. Since I bought it I've gotten the carb "cleaned out", new spark plug, new battery, drained the tank and filled with gas and a system cleaner. So the issue that I'm having is no matter how much fine tuning of the choke, throttle, mixture screw and everything I cannot get it to go. It starts up and idles decent but when I give it throttle it just dies out. Again I'm kind of new to motorcycles so I'm not fully knowledgeable with them I mainly work on cars so any information will be helpful. Thanks in advanced, and if you need any more info from me about the bike please let me know!



Login or Register to Remove Ads
justincan423 is offline  
Reply With Quote
Old 05-20-2017, 04:29 PM   #2
blaine
Senior Member
 
blaine's Avatar
 
Join Date: Feb 2010
Location: P.E.I. Canada
Posts: 3,784
Almost sounds like a vacuum leak.....Have you checked around boots & petcock hose for leaks?.........Other thing that comes is a torn or not seated in grove diaphram.
__________________
If at first you do succeed, try not to look surprised.


blaine is offline  
Reply With Quote
Old 05-20-2017, 08:09 PM   #3
justincan423
Junior Member
 
Join Date: Mar 2017
Posts: 6
Quote:
Originally Posted by blaine View Post
Almost sounds like a vacuum leak.....Have you checked around boots & petcock hose for leaks?.........Other thing that comes is a torn or not seated in grove diaphram.


No leaks in petcock hose or anything and by grove diaphragm do you mean where the carb goes into the block? Both sides are good no tips or anything in air box boot either. Is there a way to do a vacuum leak test like you can on a car?



Login or Register to Remove Ads
justincan423 is offline  
Reply With Quote
Old 05-20-2017, 08:56 PM   #4
spldart
Senior Member
 
spldart's Avatar
 
Join Date: May 2015
Location: Stafford, Texas
Posts: 604
I'm starting to get the same problem with my 2000. As if I needed more problems.
My start regime is this:
full choke and crank.
modulate the choke for the first 10 to 30 seconds then settle it into an idle.
If I simply get on the throttle it will just die.
if I rev rev rev rev the throttle really fast to build revs I can get underway.
warming it up is best done by short shifting to prevent overrev but keep the throttle pinned.
after 1 or 2 miles I can keep it running fairly easy.
Less than that and if I don't do everything perfect it just dies over and over.

Found a Mikuni carb expert website.
It says Pilot circuit problems or vaccum leak.

Thing about a vacumm leak is once you get it started and idling if you hose
it with starter fluid *auto parts store* it should react big time.
Be johnny on the spot with the ignition kill and a fire extinguisher though.

I plan on trying this on mine.
Don't spray the carb intake. It's prolly not your problem. Spray the boot between the engine
and carb and the carb itself. Assuming you have a vacumm leak.
The intake of the carb will react even if the carb is perfect.

Don't overspray. If you have a vacumm leak it should react dramatically.

Last edited by spldart; 05-20-2017 at 09:01 PM. Reason: I'm talking engine starter fluid/spray from auto parts store by the way. Not something you would grill with.
spldart is offline  
Reply With Quote
Old 05-20-2017, 10:12 PM   #5
blaine
Senior Member
 
blaine's Avatar
 
Join Date: Feb 2010
Location: P.E.I. Canada
Posts: 3,784
Quote:
Originally Posted by justincan423 View Post
No leaks in petcock hose or anything and by grove diaphragm do you mean where the carb goes into the block? Both sides are good no tips or anything in air box boot either. Is there a way to do a vacuum leak test like you can on a car?
Sorry...I mean the slide diaphram when you take the top cover off.
__________________
If at first you do succeed, try not to look surprised.





Login or Register to Remove Ads
blaine is offline  
Reply With Quote
Old 05-20-2017, 11:38 PM   #6
justincan423
Junior Member
 
Join Date: Mar 2017
Posts: 6
Quote:
Originally Posted by spldart View Post
I'm starting to get the same problem with my 2000. As if I needed more problems.
My start regime is this:
full choke and crank.
modulate the choke for the first 10 to 30 seconds then settle it into an idle.
If I simply get on the throttle it will just die.
if I rev rev rev rev the throttle really fast to build revs I can get underway.
warming it up is best done by short shifting to prevent overrev but keep the throttle pinned.
after 1 or 2 miles I can keep it running fairly easy.
Less than that and if I don't do everything perfect it just dies over and over.

Found a Mikuni carb expert website.
It says Pilot circuit problems or vaccum leak.

Thing about a vacumm leak is once you get it started and idling if you hose
it with starter fluid *auto parts store* it should react big time.
Be johnny on the spot with the ignition kill and a fire extinguisher though.

I plan on trying this on mine.
Don't spray the carb intake. It's prolly not your problem. Spray the boot between the engine
and carb and the carb itself. Assuming you have a vacumm leak.
The intake of the carb will react even if the carb is perfect.

Don't overspray. If you have a vacumm leak it should react dramatically.


Awesome thank you for the information. I'll try that out possibly tomorrow and let you know how I make out
justincan423 is offline  
Reply With Quote
Old 05-20-2017, 11:40 PM   #7
justincan423
Junior Member
 
Join Date: Mar 2017
Posts: 6
Quote:
Originally Posted by blaine View Post
Sorry...I mean the slide diaphram when you take the top cover off.


I will double check that tomorrow. Thank you! I just want to get to riding so bad this thing has been such a headache. It'll all be worth it in the end though (hopefully) [emoji1360]
justincan423 is offline  
Reply With Quote
Old 05-21-2017, 09:37 AM   #8
derbydave
Senior Member
 
derbydave's Avatar
 
Join Date: Jan 2017
Location: KS
Posts: 103
I would put money on the pilot circuit. Mine ran like crap until I cleaned the pilot jet and replaced the tiny o-ring.
__________________
2003 Suzuki GZ250 (Sold)
1986 Suzuki Cavalcade LXE
1986 Suzuki Intruder VS700
derbydave is offline  
Reply With Quote
Old 05-21-2017, 03:57 PM   #9
blaine
Senior Member
 
blaine's Avatar
 
Join Date: Feb 2010
Location: P.E.I. Canada
Posts: 3,784
Quote:
Originally Posted by derbydave View Post
I would put money on the pilot circuit. Mine ran like crap until I cleaned the pilot jet and replaced the tiny o-ring.
Yep you could have a vacuum leak there if the o-ring is bad.
__________________
If at first you do succeed, try not to look surprised.


blaine is offline  
Reply With Quote
Old 05-22-2017, 07:23 AM   #10
justincan423
Junior Member
 
Join Date: Mar 2017
Posts: 6
Quote:
Originally Posted by blaine View Post
Yep you could have a vacuum leak there if the o-ring is bad.


Sorry to be annoying but being that I'm new to the carb game, which o-ring are you taking about? When I took the carb apart to clean it the only o-ring I saw was the one on what I believe is the main jet, the pilot jet did not have one on it. Is it supposed to? Because that could be my issue right there. The carb refresh kit I bought came with a few little o-rings that I'm not sure where they go. Thanks again for the advice!
justincan423 is offline  
Reply With Quote
Reply



Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 06:04 AM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.