YFZ Central banner
21 - 40 of 44 Posts

·
Registered
Joined
·
16 Posts
Discussion Starter · #21 ·
Originally posted by XXX@Nov 17 2005, 04:06 PM
If it fixes it temporary then you may have isolated the problem, have you tried running with the choke on or partially on? you might just have trash in the tank filter.  its just a thought
[snapback]326083[/snapback]​
True. My hombre ordered an inline filter, and we are pulingthe carbs apart this weekend to check for any trash in the fuel system.

Thanks for your input. It is greatly appreciated.
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #22 ·
Originally posted by Alba450@Nov 17 2005, 03:15 PM
Mine cuts at full throttle, ive done all the usuals to try and fix this. Im wondering abut the spark plug though. Ive changed it already but i know i tightened it but didnt really wrench it down as i figured would not be good. U think im not getting all the spark. Im good unless try all out full throttle then it cuts out (really sucks!). I feel you pain man !
[snapback]326053[/snapback]​
Thanks Alba. I went to my local Yamaha dealer yesterday to get some replacement jets for the 33mm Mikuni carbs on my Raptor, and spoke with one of the techs. He said to try to loosen the gas cap a bit while it's cutting out. He said if it picks right up, then replace the gas cap. The tank should be vented, and will cause a fuel deficiency problem if it's not breathing right, thus causing it to run sluggish or fall flat on it's face when your on the throttle.

Hope your bike gets better, good luck!
 

·
Registered
Joined
·
110 Posts
Originally posted by Flynbyu@Nov 18 2005, 11:08 AM
Bull-butter.

Not trying to start up a pissing match, maybe I've just got a good Raptor, but I haven't been beat by a YFZ450, BANSHEE, DS 650, or a Predator in a drag race. It gets a little old, everyone and their brother coming up and asking you "Is that thing fast?". Two weeks ago I had some guy approach me on a 86' Honda 250R THREE WHEELER and wanted to run for $20 bucks! I told him "I would feel bad taking his riding money for next week." I ran him anyway. He didn't even stop back by and visit with our little riding group after I smoked him like a Thanksgiving turkey.

There is no replacement for displacement, other than spending HUGE amount of money on technology to make a bike perform better. 95% is the rider, the other 5% is the equipment.  Given, if I were to buy a bike to race, it would be the YFZ 450 hands down. It's got a sweet suspension, and it's easily tuned. Lots of gizmos out there in the marketplace that are totally trick. To trail ride, or to hit the dunes, I'm sticking to my Raptor.

It's not about going the fastest, it's about getting some seat time in and having fun.

The best bike that I have ran has been a YFZ 450. It had been as modified as much my Raptor, and it's the one that's a bit sick now.
[snapback]326506[/snapback]​

so your saying that everything you race you beat? well im guessing everyone you race doesnt get out of 2nd gear. a predator is faster then a raptor.yes there is no substitute for engine size...BUT.... when the raptor is 50 lbs heavier then the yfz, and has 5 hp less then the 450 stock, the 450 just revs faster and quicker. yfz has 11.5:1 compression, the raptor has 9.2:1 compression. i mean come on, my buddy has a pretty built raptor, cams, big bore kit, ect and i still smoke his doors on my yfz. the raptors are not that fast and really a 400ex is faster. so unless you have one serious built raptor and runing pure stock quads, no way is it faster then a yfz. if your close to me (ohio) i would lay my tittle down on the line to run you. i ran across raptor guys before saying there faster, but yet they always back down when i slam my tittle on the line and run for tittles. i have owned a raptor and they are no way near as quick as theses.
 

·
Registered
Joined
·
38 Posts
Originally posted by Flynbyu@Nov 18 2005, 11:10 AM
True. My hombre ordered an inline filter, and we are pulingthe carbs apart this weekend to check for any trash in the fuel system.

Thanks for your input. It is greatly appreciated.
[snapback]326507[/snapback]​
Don't forget about cleaning out your pitcock in your gas tank.
 

·
Registered
Joined
·
31 Posts
Originally posted by Flynbyu@Nov 18 2005, 11:16 AM
Thanks Alba. I went to my local Yamaha dealer yesterday to get some replacement jets for the 33mm Mikuni carbs on my Raptor, and spoke with one of the techs. He said to try to loosen the gas cap a bit while it's cutting out. He said if it picks right up, then replace the gas cap. The tank should be vented, and will cause a fuel deficiency problem if it's not breathing right, thus causing it to run sluggish or fall flat on it's face when your on the throttle.

Hope your bike gets better, good luck!
[snapback]326510[/snapback]​

Maybe that will be it so I would be helpful :smile: Wonder why some of the bikes come with no vent tubes?
 

·
Registered
Joined
·
244 Posts
my bike seems to be having the same problem as yours. cutting out at about 1/2 throttle on up to nearly full throttle, then it seems to clear up. on occasion it doesnt even do it and sometimes itll barely run. new spark plug, new piston(needed rebuilt anyway) with no luck. im about sick of that w00ter i know that. cant imagine its the gas cap, although havent tried that. maybe a faulty rev limiter? oil sensor unit? will that kill the engine if its low on oil? maybe its junk? only other thing i thought was maybe just enough coolant getting into the cylinder to make it run like w00ter at 1/2 throttle, but not enough to hinder performance at full throttle. im about out of guesses. i really dont think its coolant tho. anyone got anything else?
 

·
Premium Member
Joined
·
13,948 Posts
Originally posted by locogato11283@Nov 20 2005, 06:29 PM
my bike seems to be having the same problem as yours. cutting out at about 1/2 throttle on up to nearly full throttle, then it seems to clear up. on occasion it doesnt even do it and sometimes itll barely run. new spark plug, new piston(needed rebuilt anyway) with no luck. im about sick of that w00ter i know that. cant imagine its the gas cap, although havent tried that. maybe a faulty rev limiter? oil sensor unit? will that kill the engine if its low on oil? maybe its junk? only other thing i thought was maybe just enough coolant getting into the cylinder to make it run like w00ter at 1/2 throttle, but not enough to hinder performance at full throttle. im about out of guesses. i really dont think its coolant tho. anyone got anything else?
[snapback]327245[/snapback]​
I'm sure you checked it but maybe your jetting...now that the weather is turning cooler.....
 

·
Premium Member
Joined
·
13,948 Posts
Originally posted by locogato11283@Nov 20 2005, 07:03 PM
yea thats not it. that was first thing that came to mind but its been doing it since it was in the 70's..
[snapback]327268[/snapback]​
I'm just shooting out ideas here but a guy I ride with had a similar problem and it turned out to be his float adjustment was out of wack..... :wtf:

Have you gone thru the carb to make sure everything is clean????
 

·
Registered
Joined
·
244 Posts
Originally posted by YFZ450alterego@Nov 20 2005, 03:06 PM
I'm just shooting out ideas here but a guy I ride with had a similar problem and it turned out to be his float adjustment was out of wack..... :wtf: 

Have you gone thru the carb to make sure everything is clean????
[snapback]327271[/snapback]​
no i havent. tryin to save that for last. i hate that carb, everything about it.its all big and lumpy and has 10000 things hangin off it. soo, im tryin to makethat my last resort. like i said, itruns fine sometimes and others like total ass... :wtf:
 

·
Premium Member
Joined
·
13,948 Posts
Originally posted by locogato11283@Nov 20 2005, 07:35 PM
no i havent. tryin to save that for last. i hate that carb, everything about it.its all big and lumpy and has 10000 things hangin off it. soo, im tryin to makethat my last resort.  like i said, itruns fine sometimes and others like total ass... :wtf:
[snapback]327284[/snapback]​
That's exactly what his was doing.....it would run fine then start running like crap...he'd let it set for 15 minutes or so and it would be fine for a bit and then run like crap again....

Here's his post on another forum:

Hey,
We went out to Mr. T's to ride today and the thing ran like w00ter??? It started fine and as long as I went slow it was fine also. I hit second and giving it gas and it started to choke(run ruff)?? I pulled the plug and it ran fine for the first half lap, then did it again. I put in another plug and this time it lasted a lap + before it got w00terty. The last out I had let it sit for about 15 min and took off to do another lap and it did it again, I just punched it and it cleared up after about 100ft? Didn't do it again after that. Got any ideas?????
 

·
Premium Member
Joined
·
13,948 Posts
Originally posted by locogato11283@Nov 20 2005, 11:03 PM
yea same w00ter mines doing. need to get this figured out. its not very fun hillclimbing when its runnin like that.
[snapback]327396[/snapback]​
Again...I'm not saying that's your problem but it's worth a shot. He had to pull the carb out and turn it upside down and measure the float clearance...I remember him saying something about it needed to be at like a 8mm measurement.

It's covered in the service manual on the float adjustment...I'll look at mine tonight and see if there's any special things you need to do. I think it's an easy fix..... :smile:
 

·
Registered
Joined
·
244 Posts
Originally posted by YFZ450alterego@Nov 21 2005, 03:03 AM
Again...I'm not saying that's your problem but it's worth a shot.  He had to pull the carb out and turn it upside down and measure the float clearance...I remember him saying something about it needed to be at like a 8mm measurement.

It's covered in the service manual on the float adjustment...I'll look at mine tonight and see if there's any special things you need to do.  I think it's an easy fix..... :smile:
[snapback]327519[/snapback]​
well only thing that im thinkin is how can the float clearance have anything to do with half throttle cutting out? i can see if it was full throttle when the bowl is draining the fastest. at half throttle it shouldnt be consuming enough gas to run it dry. and if its runnin itdry at half throttle then fullthrottle shouldnt even work...justa thought.
 

·
Premium Member
Joined
·
13,948 Posts
Originally posted by locogato11283@Nov 21 2005, 11:58 AM
well only thing that im thinkin is how can the float clearance have anything to do with half throttle cutting out? i can see if it was full throttle when the bowl is draining the fastest. at half throttle it shouldnt be consuming enough gas to run it dry. and if its runnin itdry at half throttle then fullthrottle shouldnt even work...justa thought.
[snapback]327566[/snapback]​
I remember asking him that very same question.....it didn't make sense to me either. :wtf:

I thought for sure it was jetting or something being dirty. So he messed with the jetting a bit, cleaned the carb and adjusted the fuel screw. Nothing worked...still ran like crap.

But all I know is that he took it off, adjusted the floats and the problem never came back. :icon_eek:

Just trying to help......good luck. I know it's frustrating. :icon_neutral:
 

·
Registered
Joined
·
47 Posts
Originally posted by YFZ450alterego@Nov 21 2005, 01:03 PM
I remember asking him that very same question.....it didn't make sense to me either. :wtf:

I thought for sure it was jetting or something being dirty.  So he messed with the jetting a bit, cleaned the carb and adjusted the fuel screw.  Nothing worked...still ran like crap.

But all I know is that he took it off, adjusted the floats and the problem never came back. :icon_eek:

Just trying to help......good luck.  I know it's frustrating. :icon_neutral:
[snapback]327619[/snapback]​
i hate 4 strokes. ecpecially high tech ones. this could surely be caused by so many things. i guess ill keep tryin new things until i figure out what it is.. :angryfire:

honestly it feels electrical to me. thats y i havent messed with the carb yet. its not the type of cutting out at too much gas or not enough makes. its an instant on/off cutting out which leads me to believe its electrical. this bike has been rolled more times than i can remember, so that may be playin a part in it.
 

·
Registered
Joined
·
244 Posts
Originally posted by stclark816@Nov 21 2005, 11:25 AM
i hate 4 strokes. ecpecially high tech ones. this could surely be caused by so many things. i guess ill keep tryin new things until i figure out what it is.. :angryfire:

honestly it feels electrical to me. thats y i havent messed with the carb yet. its not the type of cutting out at too much gas or not enough makes. its an instant on/off cutting out which leads me to believe its electrical. this bike has been rolled more times than i can remember, so that may be playin a part in it.
[snapback]327631[/snapback]​
that was actually me. forgot my bros name was signed in..
 

·
Premium Member
Joined
·
13,948 Posts
Originally posted by locogato11283@Nov 21 2005, 03:26 PM
that was actually me. forgot my bros name was signed in..
[snapback]327632[/snapback]​
I was getting ready to reply with a :wtf: is your problem........ :mhihi:


Did you check the little wire near the battery ground that runs to the motor???? It sometimes comes unplugged or doesn't make contact....especially while the quad is underway.....it troubled me for 4 days until I touched it and the quad would run good and then come back.

Check all the wiring and look for a "short" in the wiring harness also. An electrical gremlin is the most frustrating one to diagnose. :rant2:
 

·
Registered
Joined
·
244 Posts
Originally posted by YFZ450alterego@Nov 21 2005, 11:30 AM
I was getting ready to reply with a  :wtf:  is your problem........ :mhihi:
Did you check the little wire near the battery ground that runs to the motor????  It sometimes comes unplugged or doesn't make contact....especially while the quad is underway.....it troubled me for 4 days until I touched it and the quad would run good and then come back.

Check all the wiring and look for a "short" in the wiring harness also.  An electrical gremlin is the most frustrating one to diagnose. :rant2:
[snapback]327633[/snapback]​
yea im gonna start unplugging w00ter and tryin different stuff. im damn near positive its electrical. im gonna check all thestuff by the battery and all the other wiring. who knows, maybe ill come across something. thanks for the help man..
 

·
Registered
Joined
·
16 Posts
Discussion Starter · #40 ·
Originally posted by bansheeman@Nov 18 2005, 03:45 PM
so your saying that everything you race you beat? well im guessing everyone you race doesnt get out of 2nd gear. a predator is faster then a raptor.yes  there is no substitute for engine size...BUT.... when the raptor is 50 lbs heavier then the yfz, and has 5 hp less then the 450 stock, the 450 just revs faster and quicker. yfz has 11.5:1 compression, the raptor has 9.2:1 compression. i mean come on, my buddy has a pretty built raptor, cams, big bore kit, ect and i still smoke his doors on my yfz. the raptors are not that fast and really a 400ex is faster.  so unless you have one serious built raptor and runing pure stock quads, no way is it faster then a yfz.  if your close to me (ohio) i would lay my tittle down on the line to run you. i ran across raptor guys before saying there faster, but yet they always back down when i slam my tittle on the line and run for tittles. i have owned a raptor and they are no way near as quick as theses.
[snapback]326601[/snapback]​
Blah....Blah....Blah.....

The part I liked the most about your rant: "the raptors are not that fast and really a 400ex is faster"

HA!!!!!!!! HA!!!!!!!!!!!

Yeah, and Maurice Clarett was the best thing to come out of Ohio State too, right?



Are you seeing airplanes?


Because I swear your living on Fantasy Island.



Maybe no one knows how to ride in Ohio but you, I don't know. All I can say is I've out ran EVERYTHING in a straight line on both sides of the Arkansas River in Arkansas and Oklahoma and the only thing that came CLOSE was a YFZ450. Too bad you didn't live closer. I'd be glad to let you ride it on a track, in the sand, with GreenEggsandHam, whatever. If we ran for titles, I hate for you to miss second gear, or something lame and loose you bike. I would also hate to loose mine. Best two outta three?

Have a Happy Thanksgiving up in Ohio.......
 
21 - 40 of 44 Posts
Top