Raptor Forum banner

Shot Floats? Engine Hydrolock Multiple Times

2K views 9 replies 3 participants last post by  QuadManiac 
#1 ·
I believe I am having a problem with my float sticking. I have a 2005 raptor 660 that if the gas is left on will fill the motor with gas and hydrolock the motor. I thought that this was just a sticky needle and seat so I rebuilt the carbs last year changed the oil and drained the motor. First time out this year I accidently left the gas on and sure enough same thing. So now I have drained the motor again and did another oil change but would hate to get stuck on the trail with a hydrolocked motor. Is this a problem with the floats or is this due to another part of the carb? Should I try ordering a carb rebuild kit and new floats from yamaha? Kinda lost on where to go next. All help is greatly appricated.

Tory
 
#2 ·
The overflow tubes should prevent carb overflow into the cylinder... I suggest you find why they are not working - either plugged up, or perhaps, as we have seen here in the forum, some numb nut previous owners would JB weld the o-flows shut to stop the fuel dribbling out the bottom (instead of fixing the real problem).

Also, the overflow condition is likely caused by leaking o-ring under the float seat... they always seem to start leaking after cleaning the carbs - need a new one!
 
#3 ·
No I did not, and come to think of it the O-rings looked pretty loose(kind of a pain to get seat back in). It looks like yamaha sells the needle, seat and o-ring as a whole for 15 bucks a carb:


http://www.yamahapartsnation.com/oemparts/a/yam/5003915ff870021f60a0d4af/carburetor


29
. . Needle Valve Set
5LP-14107-20-00
$14.66

If you think this is the issue will likely order these and then try to work to figure out why my over flows are plugged. Filling the motor is really a pain. Is there anything else I should look at or replace when I am in there that you think could be suspect to this problem. Definitely takes some time to get carbs in and out of these machines. Thanks a bunch for the help. Have heard alot of great things about your advice on this site!

Tory
 
#4 ·
To get fuel into the cylinder requires 2 things - leaking float valve and plugged overflow... Fix them, hydrolock stops.

If you store your quad with rear wheels much higher than front you can also leak fuel into the cylinder... but this is not a common thing to do.
 
  • Like
Reactions: DEZPERADO
#5 ·
I order a carb rebuild kit today with new float valves,seats and gaskets included. Should come in sometime next week so I should be able to hopefully get it all swapped out then and figure out why my overflow is plugged. Do you think this should do the trick or will I need to get the physical float itself as well? Thanks a bunch for the help, I really appreciate it.
 
#6 ·
I am also somewhat interested, has anyone ever heard of people having problems with a "hanging idle" when riding? It seems as though when you let off the gas the raptor doesn't come down off higher rpm's like it should. It will stay at a higher rpm until you start to apply the brakes and manually slow down the motor. I am interested if this has to do with my overflows being plugged or if something else in these carbs could possibly be plugged off. Has anyone ever had this issue???

Tory
 
#8 ·
Hanging idle = lean pilot jets or fuel screws, often = dirty carbs.

Leaking overflow often = dirty carbs.

See a pattern here?
 
#9 ·
Got Carbs apart tonight. The Pilot jet is a 25 and the main is a 160. Pulled off the two overflow hoses on the carb bowls. Turns out something crawled up and died in the end of one of the plastic ends on these houses. Cleaned it out with a flat tip and now both flow freely when blown through. I got the carb rebuild kit so I will be replacing the float needle, seat and o-ring. The factory jets are different then what is ran in this quad so I believe I will just soak and blow out the jets, then replace the o rings. O-ring under main looks pretty bad.

-Is the overflow just the two tubes that connect to the bowl? As long as they flow free now I should be good?

-As long as I soak and clean jets they should be good?

-Plan on clean everything out with carb cleaner and they blowing out with air compressor. Is there anything else I should check for specificly or clean?
 
#10 · (Edited)
You fixed the plugged o-flow, next the leaky float valve. Make sure you clean ALL fuel wetted jets and passages - and see light thru the pilot jets.

Sometimes using copper wire strands (like from speaker wire) is necessary to get the goop out of the jets - cleaner and air isn't always enough. Be thorough!
 
  • Like
Reactions: DEZPERADO
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top