another problem

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kstevens · #1 Post by **kstevens** » Wed Dec 07, 2011 1:09 am

quad ran fine for a long time.... (yrs) then started to shut off after a 15-20 run, act like running out of fuel... it would bog and stall when throttle was applied, sit on the trail for 10 min with fan running, it would start and run back to truck, i have replaced temp sensor, fuel filter, rerouted fuel line..... same problem. i removed all the guts from all quick connects in fuel system....now i have another problem, now it acts like it is hitting rev limiter at only half throttle... it back fires out through exhaust but idles fine and sounds good to that point..... ANY IDEAS

rayspeed · #2 Post by **rayspeed** » Wed Dec 07, 2011 1:49 am

Pull the flywheel cover and check the flywheel for any signs for hairline cracks where it might have spun just a bit... this throws the ignition timing off. Also try pulling the relay under the air filter and see if it changes any... it should get enough current thru the key switch to run and if it better replace the relay however it is not just a normal bosch relay... it has a flashback relay or something built in and sometimes bad things can happen inside there from the vibration. Other than that make sure that the intake boot from the throttle body to the head has not cracked or come loose.

speedracer · #3 Post by **speedracer** » Wed Dec 07, 2011 1:57 am

One of my Dales was doing the same thing some time ago,swapped out the fuel pressure regulator and it worked fine,my filter would seem to run dry at times also.Maybe you have a cloged injector.

kstevens · #4 Post by **kstevens** » Wed Dec 07, 2011 3:13 am

thanks guys..i really can afford to just throw money at it, injectors are cheap enough

cannondale27 · #5 Post by **cannondale27** » Wed Dec 07, 2011 3:14 am

Sounds like a case of tight or leaking valves. Hotter they get. Tighter they get and more compression is lost. Or a decomp on the fritz. Either way. I would pull the valve cover and investigate since its way over due any how.

cdsracer · #6 Post by **cdsracer** » Wed Dec 07, 2011 2:23 pm

If nothing else works, try swapping the coil

kstevens · #7 Post by **kstevens** » Sat Dec 10, 2011 9:56 pm

QUOTE (cdsracer @ Dec 7 2011, 09:23 AM) <{POST_SNAPBACK}>

If nothing else works, try swapping the coil

i did that as well, i spent a day at the trails riding and testing, coil, temp sensor, spark plug, fuel filter, reroute fuel lines, i was concentrating on fuel system because thats what it acts like, running out of fuel, it is a new-ish fuel pump, as well

MX Quad Dad · #8 Post by **MX Quad Dad** » Sat Dec 10, 2011 11:10 pm

screen in the tank???

micro10 · #9 Post by **micro10** » Mon Dec 12, 2011 4:48 pm

QUOTE (kstevens @ Dec 7 2011, 01:09 AM) <{POST_SNAPBACK}>

quad ran fine for a long time.... (yrs) then started to shut off after a 15-20 run, act like running out of fuel... it would bog and stall when throttle was applied, sit on the trail for 10 min with fan running, it would start and run back to truck, i have replaced temp sensor, fuel filter, rerouted fuel line..... same problem. i removed all the guts from all quick connects in fuel system....now i have another problem, now it acts like it is hitting rev limiter at only half throttle... it back fires out through exhaust but idles fine and sounds good to that point..... ANY IDEAS

My LTR450 started acting the same way about two months ago,changed fuel pump, changed filter ,changed pressure regulator ,changed fuel lines,cleaned the tank,still acting up.Started to change the ignition then decided to clean the injector.Got a pile of used parts now over a dirty injector.