Idling problem and backfires

40calPUNISHER · 02-05-2012, 01:17 AM

Just got a '04 Z400 and dont have much history on it. Dont know if it has been jetted or not. It has Dynojet decals, not sure if thats a factory option and has a dynojet kit (not sure if that has anything to do with anything or not just throwing that out there). What I do know is it has this muffler (pictured below), I dont know if you can "punch" them out but you can see straight through it and it doesnt have that smaller inner circle sticking out of the tailpipe like the picture shows. It also didnt have a air filter on it and dont know how long previous owner rode without it. Carb is prolly filthy. I have put a air filter on it. NOW for the problem. It idles fine with the choke on but if you take the choke off it dies within 10 seconds. Choke on and give it gas it is fine, choke off and give it gas it back fires a lot. Does it whether the engine is hot or cold. Waiting on a manual before I tear into it but until then any help would be awesome.

Pulido221 · 02-05-2012, 02:33 AM

Quote:

Originally Posted by 40calPUNISHER

Just got a '04 Z400 and dont have much history on it. Dont know if it has been jetted or not. It has Dynojet decals, not sure if thats a factory option and has a dynojet kit (not sure if that has anything to do with anything or not just throwing that out there).

Lol! My first thought would be that the pilot jet is dirty and partially plugged up. I think all jets are probably dirty and plugged up lol. Your gona have to take it a part and remove jets and clean them out. While you have them out, write down what jet sizes are in there so we can start helping and leading you in the right direction

40calPUNISHER · 02-05-2012, 04:15 PM

SO, until the manual comes in the mail is it okay to keep riding with the choke on? Can this cause any kind of damage?

spize909 · 02-05-2012, 04:36 PM

Clean the pilot jet.

40calPUNISHER · 02-06-2012, 10:23 PM

Jets are 144, 60 and 22.5

biggiej42 · 02-06-2012, 10:41 PM

Check your valve lash too, riding with no filter will certainly wipe your valves out.

40calPUNISHER · 02-06-2012, 10:46 PM

Are those jets right for riding at 750-800ft?

biggiej42 · 02-06-2012, 11:15 PM

Is it a full pipe, or just the slipon? Open air box lid?

40calPUNISHER · 02-06-2012, 11:57 PM

slip on, stock box. Also, I pulled the spark plug and it was black. Doesnt that mean it running rich? I've got one of those spark plug sand blaster things so I blasted it and popped it back in.

Good news, I cleaned the carb and now it runs just fine.
Bad news, the float bowl gasket was pinched and now it leaks...

Gremlin · 02-07-2012, 12:17 AM

You win some.. you loose some! :P

I got all my stuff back together and quad wouldn't stay running.. checked all air flow for gaps.. fuel delivery.. spark all that for an hour. Turns out.. I forgot the little tiny spring on my needle inside the carb. Had to take it all apart again lol.

40calPUNISHER · 02-07-2012, 12:29 AM

Just took the bowl off and re-aligned the gasket/o ring and it stopped leaking!!! Im back in business!

Gremlin · 02-07-2012, 12:41 AM

Awesome! Good to hear it!

Pulido221 · 02-07-2012, 01:06 AM

See how quick we help to get people out there riding again lol! Don't forget to buy a new bowl oring gasket, keep that air filter clean, and change that oil ASAP if you haven't already done so.

Gremlin · 02-07-2012, 01:17 AM

I would also pull the hubs and check the bearings up front. Possibly even the rear carrier as well. Both are pretty easy to inspect

I bought my quad used and the front bearings shot in like the first month. Looked like they were the original bearings from 6 years ago lol.

40calPUNISHER · 02-07-2012, 01:20 AM

Thanks for the help!!!
I will be changing the oil soon cuz it needs a clutch too. Its pretty much gone.
Back to the jetting question, are those jets the right size?

02-05-2012, 01:17 AM	#1 (permalink)
40calPUNISHER :::Rookie Rider::: Join Date: Feb 2012 Posts: 25	Idling problem and backfires Just got a '04 Z400 and dont have much history on it. Dont know if it has been jetted or not. It has Dynojet decals, not sure if thats a factory option and has a dynojet kit (not sure if that has anything to do with anything or not just throwing that out there). What I do know is it has this muffler (pictured below), I dont know if you can "punch" them out but you can see straight through it and it doesnt have that smaller inner circle sticking out of the tailpipe like the picture shows. It also didnt have a air filter on it and dont know how long previous owner rode without it. Carb is prolly filthy. I have put a air filter on it. NOW for the problem. It idles fine with the choke on but if you take the choke off it dies within 10 seconds. Choke on and give it gas it is fine, choke off and give it gas it back fires a lot. Does it whether the engine is hot or cold. Waiting on a manual before I tear into it but until then any help would be awesome. Last edited by 40calPUNISHER; 02-05-2012 at 01:32 AM.

02-05-2012, 04:36 PM	#4 (permalink)
spize909 :::Get a life! You're over 5000 posts::: Join Date: Oct 2008 Location: Southern California Posts: 5,245	Clean the pilot jet. __________________ 2005 Z-400 Mine *January* *2011 QOTM* 2004 Z-400 Brad'Z *October 2011 QOTM* http://www.suzukicentral.com/forums/...tm-winner.html 2004 Z-400 Wife's 1996 Sandsprite IV (sandrail) MINE Sponsors: Coors Light.............I sponsor them! *Life is tough...........it's tougher if you're stupid.*

02-06-2012, 10:41 PM	#6 (permalink)
biggiej42 :::Official Spammer::: Join Date: Jun 2006 Posts: 3,390	Check your valve lash too, riding with no filter will certainly wipe your valves out. __________________ 05' Z434 12.5:1CP,Full Yosh TRC,FCR40,175/45,Rat Stack,Dyna Programmable,AMR Coil,KW Valvetrain,536/540 Web's,DID Tchain,PWR Radiator,Raptor petcock,Gunnar Kill,Elka S3 Front+Rear w/link,Roll+1 Stem,GPR Stabilizer,SL Hyd.Clutch,Tag T2,LSR+3 Arms,Burgard+1 Swinger,Quadtech Rad Shrouds,Supersprox 14/40t,UM Air Box,YFZ Calipers,SS Lines,PA Bumper,Asv's,Roll Nerfs/Heels/Pegs,LSR Axcalibar,Douglas G2 Beadlocks/Razr's,Hid,YFZTail,Pwrmadd's,TT Vapor+Dash,CV4's,RickyStator. July 2011 QOTM

02-06-2012, 11:15 PM	#8 (permalink)
biggiej42 :::Official Spammer::: Join Date: Jun 2006 Posts: 3,390	Is it a full pipe, or just the slipon? Open air box lid? __________________ 05' Z434 12.5:1CP,Full Yosh TRC,FCR40,175/45,Rat Stack,Dyna Programmable,AMR Coil,KW Valvetrain,536/540 Web's,DID Tchain,PWR Radiator,Raptor petcock,Gunnar Kill,Elka S3 Front+Rear w/link,Roll+1 Stem,GPR Stabilizer,SL Hyd.Clutch,Tag T2,LSR+3 Arms,Burgard+1 Swinger,Quadtech Rad Shrouds,Supersprox 14/40t,UM Air Box,YFZ Calipers,SS Lines,PA Bumper,Asv's,Roll Nerfs/Heels/Pegs,LSR Axcalibar,Douglas G2 Beadlocks/Razr's,Hid,YFZTail,Pwrmadd's,TT Vapor+Dash,CV4's,RickyStator. July 2011 QOTM

02-07-2012, 12:17 AM	#10 (permalink)
Gremlin :::Eiger Rider::: Join Date: Nov 2009 Location: Manhattan, KS Posts: 613	You win some.. you loose some! :P I got all my stuff back together and quad wouldn't stay running.. checked all air flow for gaps.. fuel delivery.. spark all that for an hour. Turns out.. I forgot the little tiny spring on my needle inside the carb. Had to take it all apart again lol. __________________ '03 Z400 -13t Front Sprocket -Uni Air Filter -'06 Z400 Stock Ressie Shocks -All Balls Rear Bearing Kit -Cylinderworks Big Bore -Port/Polish (Advantage Cycle) -Pro Circuit T4 Full Exhaust -Ferrea Stainless Valves -Dyna Chip Non-Programmable -DRZe Kit -Big Bear Clutch Kit -Edelbrock Carb -Stage 1 Hotcams -Maxxis Razr 2's Full Set -Tusk Slotted Rear Rotor '01 GSX-R 750 -Under tail -Fender Eliminator -Flush mount front flashers

02-05-2012, 04:15 PM	#3 (permalink)
40calPUNISHER :::Rookie Rider::: Join Date: Feb 2012 Posts: 25	SO, until the manual comes in the mail is it okay to keep riding with the choke on? Can this cause any kind of damage?

02-06-2012, 10:23 PM	#5 (permalink)
40calPUNISHER :::Rookie Rider::: Join Date: Feb 2012 Posts: 25	Jets are 144, 60 and 22.5

02-06-2012, 10:46 PM	#7 (permalink)
40calPUNISHER :::Rookie Rider::: Join Date: Feb 2012 Posts: 25	Are those jets right for riding at 750-800ft?

02-06-2012, 11:57 PM	#9 (permalink)
40calPUNISHER :::Rookie Rider::: Join Date: Feb 2012 Posts: 25	slip on, stock box. Also, I pulled the spark plug and it was black. Doesnt that mean it running rich? I've got one of those spark plug sand blaster things so I blasted it and popped it back in. Good news, I cleaned the carb and now it runs just fine. Bad news, the float bowl gasket was pinched and now it leaks...

02-07-2012, 12:29 AM	#11 (permalink)
40calPUNISHER :::Rookie Rider::: Join Date: Feb 2012 Posts: 25	Just took the bowl off and re-aligned the gasket/o ring and it stopped leaking!!! Im back in business!

02-07-2012, 12:41 AM	#12 (permalink)
Gremlin :::Eiger Rider::: Join Date: Nov 2009 Location: Manhattan, KS Posts: 613	Awesome! Good to hear it! __________________ '03 Z400 -13t Front Sprocket -Uni Air Filter -'06 Z400 Stock Ressie Shocks -All Balls Rear Bearing Kit -Cylinderworks Big Bore -Port/Polish (Advantage Cycle) -Pro Circuit T4 Full Exhaust -Ferrea Stainless Valves -Dyna Chip Non-Programmable -DRZe Kit -Big Bear Clutch Kit -Edelbrock Carb -Stage 1 Hotcams -Maxxis Razr 2's Full Set -Tusk Slotted Rear Rotor '01 GSX-R 750 -Under tail -Fender Eliminator -Flush mount front flashers

02-07-2012, 01:06 AM	#13 (permalink)
Pulido221 :::Post Whore::: Join Date: Jul 2010 Location: Fresno, Ca Posts: 2,331	See how quick we help to get people out there riding again lol! Don't forget to buy a new bowl oring gasket, keep that air filter clean, and change that oil ASAP if you haven't already done so. __________________ Houser +2 a arms ( tric trac ) ProArmor nerfs,bump,grab bar Renthal Fat Bars ( magrath ) Houser +2 antivibe steer stem Fox Podium X front shocks TCS MX rear shock ASV unbreakable levers Full Curtis Sparks exhaust Dyno jet kit/FCI intake Old style hot cams Int/Ex ITP GNCC tires +2 GForce hubs Quadtech carbon fiber hood Kfx450R Monster graphic kit 450 BBK 13.1 JE piston KB valves / DRZ springs Mild ported head by me " WEAR A DAMN HELMET "

02-07-2012, 01:17 AM	#14 (permalink)
Gremlin :::Eiger Rider::: Join Date: Nov 2009 Location: Manhattan, KS Posts: 613	I would also pull the hubs and check the bearings up front. Possibly even the rear carrier as well. Both are pretty easy to inspect I bought my quad used and the front bearings shot in like the first month. Looked like they were the original bearings from 6 years ago lol. __________________ '03 Z400 -13t Front Sprocket -Uni Air Filter -'06 Z400 Stock Ressie Shocks -All Balls Rear Bearing Kit -Cylinderworks Big Bore -Port/Polish (Advantage Cycle) -Pro Circuit T4 Full Exhaust -Ferrea Stainless Valves -Dyna Chip Non-Programmable -DRZe Kit -Big Bear Clutch Kit -Edelbrock Carb -Stage 1 Hotcams -Maxxis Razr 2's Full Set -Tusk Slotted Rear Rotor '01 GSX-R 750 -Under tail -Fender Eliminator -Flush mount front flashers

02-07-2012, 01:20 AM	#15 (permalink)
40calPUNISHER :::Rookie Rider::: Join Date: Feb 2012 Posts: 25	Thanks for the help!!! I will be changing the oil soon cuz it needs a clutch too. Its pretty much gone. Back to the jetting question, are those jets the right size?

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