81 yamaha maxim problems...help plz! - Motorcycle-Journal Forums

gjewison · 06-10-2007, 10:00 PM

Well i got the bike going and everything was fine until the carbs started to make sucking sounds and if i pop the vaccume line off of the petcock it makes a slurping noise, spits out gas and is hot and can see steam coming out of the hose also....also when the carbs are making a slurping noise i think the gas is getting into the cylinders and into the oil so i have to keep changing the oil....and gas goes into the air cleaner area and leaks gas out a drain hose from the air box to the floor. I dont know whats wrong with it this is what i have done to the bike so far:

1. rebuild carbs including all new jets needle and seat for float. (havent replaced floats.
2. new plugs
3. new gas and vaccum lines
4. changed oil and filter a few times now that this is happening

The bike runs great but once you shut it off this happens. Is it the carbs? I have new needles and seats for the floats. But its odd and i dont know what to do. Any advice would be very helpful thanks!

Garrett

gjewison · 06-11-2007, 12:08 PM

plz help bump...

nessa · 07-09-2007, 08:43 PM

check your jet needle settings, look for stuck floats, and check your petcock settings. also try poopping the gas cap. sounds like vacuum pressure build up. there is a vent in the cap that can get clogged.

if the carbs are flooding gas into the cyl when it is not running either 1)your petcock is not in the on position, or needs a rebuild, or 2) your carb floats are stuck. (there are other possibilities, have you tuned your carbs since the rebuild?) also is your bike YICS? did you clean out the little passages that are built into the engine casing?

if nothing works, then it COULD be piston rings. before you go that far, pop the cap, get to the nearest pepboys, advanced auto whathave you and pick up some SEAFOAM. add it to your gascan and run the bike for like 5 - 10 minutes, shut 'er down and walk away, come back tomorrow and fire it up. (look out for smoke, its okay. if that didn't work then TAP the carbs at the float bowl , then lgo down the list,

if all else fails there are groups dedicated to the xj. w.xjbikes.com, w.xjplanet @ yahoo, and xjowners@micapeaks.com. i belong to all of them and they have been a GREAT source of info. (hint, ask about the xjcd from micapeaks.)

keep me updated with your progress.

Harry Palmer · 07-10-2007, 05:26 PM

Sounds like the floats,can they be in upside down?

06-10-2007, 10:00 PM	#1 (permalink)
gjewison Newbie Joined: May 2007 Bike: 1980 gs550 and 81 xj650 maxim Location: Mankato, MN Posts: 13	81 yamaha maxim problems...help plz! Well i got the bike going and everything was fine until the carbs started to make sucking sounds and if i pop the vaccume line off of the petcock it makes a slurping noise, spits out gas and is hot and can see steam coming out of the hose also....also when the carbs are making a slurping noise i think the gas is getting into the cylinders and into the oil so i have to keep changing the oil....and gas goes into the air cleaner area and leaks gas out a drain hose from the air box to the floor. I dont know whats wrong with it this is what i have done to the bike so far: 1. rebuild carbs including all new jets needle and seat for float. (havent replaced floats. 2. new plugs 3. new gas and vaccum lines 4. changed oil and filter a few times now that this is happening The bike runs great but once you shut it off this happens. Is it the carbs? I have new needles and seats for the floats. But its odd and i dont know what to do. Any advice would be very helpful thanks! Garrett Last edited by gjewison; 06-10-2007 at 10:04 PM.

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06-11-2007, 12:08 PM	#2 (permalink)
gjewison Newbie Joined: May 2007 Bike: 1980 gs550 and 81 xj650 maxim Location: Mankato, MN Posts: 13	plz help bump...

07-09-2007, 08:43 PM	#3 (permalink)
nessa Newbie Joined: Jul 2007 Posts: 5	check your jet needle settings, look for stuck floats, and check your petcock settings. also try poopping the gas cap. sounds like vacuum pressure build up. there is a vent in the cap that can get clogged. if the carbs are flooding gas into the cyl when it is not running either 1)your petcock is not in the on position, or needs a rebuild, or 2) your carb floats are stuck. (there are other possibilities, have you tuned your carbs since the rebuild?) also is your bike YICS? did you clean out the little passages that are built into the engine casing? if nothing works, then it COULD be piston rings. before you go that far, pop the cap, get to the nearest pepboys, advanced auto whathave you and pick up some SEAFOAM. add it to your gascan and run the bike for like 5 - 10 minutes, shut 'er down and walk away, come back tomorrow and fire it up. (look out for smoke, its okay. if that didn't work then TAP the carbs at the float bowl , then lgo down the list, if all else fails there are groups dedicated to the xj. w.xjbikes.com, w.xjplanet @ yahoo, and xjowners@micapeaks.com. i belong to all of them and they have been a GREAT source of info. (hint, ask about the xjcd from micapeaks.) keep me updated with your progress.

07-10-2007, 05:26 PM	#4 (permalink)
Harry Palmer Newbie Joined: Jul 2007 Posts: 17	Sounds like the floats,can they be in upside down?

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