450 hardly runs

[user101]

hey guys, 450 hardly runs. It idles ok but will only idle for about a minute before it dies. I've checked some stuff out and don't know where to go from here.

FI light is off. I unplugged the air temp sensor to check to see if the FI light would come on. It came on, I checked the code and it was for the air temp sensor. So that rules out any bad codes.

Checked all the fuses and they were all good.

Battery is good.

I've visually inspected the injector, no signs of gummed up fuel or anything.

I've read that some people have problems with the fuel regulator, how can i check this.

[blholtz]

Try this:


The fuel regulator is an easy change, not hard at all. And it is either that or your fuel filter.

Quick check for the fuel regulator. Take it off the tank. Disconnect the all lines to the regulator. Put your finger over the return outlet and blow into one of the high pressure openings. If you can blow through and hear it the regulator is bad.

[bigbad400]

idles but wont pick up... dies after idles for a min... hows your air filter? and do you have outerwears? they go bad, dont just clean it get a new one. they wont breath the same cleaned as new i dont care what people say i have done wind sock test on the material.... it holds air when its bean dirty and does not breath like new. :(

if its not that bholts hit it on the nose its prolly regulator. and btw if its your fuel filter. buy a new ltr450 filter. dont go to wall mart and try to just throw a inline filter in. these are pressurized and will blow a inline filters guts out. lol made that mistake once. :D

[user101]

Alright, just to be clear I hold my finger over the big return line and blow through one of the smaller high pressure lines and if i can blow air through it, its bad...correct?

I can hold my finger over the big (return) line and blow air through the high pressure lines.

[user101]

also, where is the best place to get one at? I checked service honda and it was $157

[blholtz]

'that is a Suzuki only part and you have to get it through a dealer. And that price is about right.

And if you can blow air through it at all it is bad.

While you have the tank off it would be a good Idea to go ahead and change the fuel filter in the swirl tank. Might as well do that well it is already apart.

Might also want to take the fuel pump off and take it apart and check the filter screen on the bottom of the motor housing. To take it apart just unscrew the 4 phillips head screws on the top of the fuel pump housing. Just to make sure there is no water in the housing.

[user101]

Thanks holtz

[blholtz]

Anytime

[Jim417mx]

Dont let the blowing air into it trick ya, I had an intermittently bad regulator, quad would run perfect then just start runnin like poo. I pulled it off, couldnt blow air through it, but replaced it with a new one and fixed my problem!

[bigbad400]

sounded to me like a pretty shotty way of checking a valve that should be checked by psi..... it needs to hold 40 some psi, with no leaks. :o

[blholtz]

It is not a perfect test by any means. But it is a test that can be done by anyone with out fancy testing equipment. And most of the time it is right on the money.

That has a spring loaded seal in it and if the seal gets buggered just a little it will allow air to pass.

Sorry if my test doesn't take a lot of gadgetry. But it gets the job done, most of the time.

And hey this dude is riding now. The test also allowed him to find the issue himself and not go on faith that someone on the forum is telling him the truth. You know people are always truthful here. :rolleyes:

[bigbad400]

25$ vacumm tester. brake bleeder... it dont take fancy equipment.... 40 psi is not much but you cant blow 40 psi in that line with your lungs. never. :o


so with that said... do you really trust it?

granted if it leaks at all, your right its bad, but you might not know its leaking unless you put 40 psi on it and see if it holds it...

btw i believe the proper number is 43 psi.

if you blow through it and you think its good and still having problems might test it the right way....:D

[blholtz]

Let's see Vacuum is measured in, inches of Mercury or inches of water, not psi. that is why a quality vacuum gauge has inHG on the dial.

Pressure is measure in pounds per square inch, Hence psi.

They are two completely different forces to react on a given part.

Hell even air pressure and liquid pressure are different. Air can be compressed and a liquid can not.

If you try to test a pressure device with a vacuum you run the risk of deforming the the sealing material. The pop off valve in this regulator is made to pushed on (pressure) not drawn out (vacuum).

Now if your think your idea is valid, quick a test. Which of the three openings on the regulator would you hook your vacuum tester to? And Why?

[user101]

alright guys calm down..but guess what, i can blow air through the new regulator.

but i can notice a difference in the amount of air that I can blow through the new regulator,( it feels like its more restricted) i put it on anyways, but i still have the same problem.

should i send the regulator back or try something else?

[user101]

I still haven't got this thing fixed. Fuel pressure is at 43 psi. New fuel filter and spark plug.

What are some other things to check out?

Should I pull the TB off and check it out?

[bigbad400]

put your vacume tester on backwards and pump it to 43 psi... this aint rocket science... i didnt say draw on the thing...



i said thats what you need to test it. a vacume tester works both ways its just a tool. mine can pump up to 120 psi and draw vacume so hard it could suck start a harley:) :rolleyes: that exaggerated obviously but you get the point.

[user101]

My fuel pressure is at 43psi. I verified this with a fuel pressure gauge.

[user101]

I still havent got this thing going.

Ive checked some more stuff out.

Fuel pump is flowing the proper amount (83 ml in 10sec)
Fuel psi is 43
Valves were in tolerance
Proper voltage at injector
Injector ohmed out properly
I visually inspected injector nothing looked clogged or dirty
new spark plug
new fuel regulator
battery is good
no codes, fi light is off
new fuel filter
cleaned filter (wasn't really dirty) in fuel pump

any other ideas?

[LTR450_#67]

Check your TPS reading.....I've seen that go bad or move somehow for some people. Also do you have your choke/high speed idle still hooked up? If so, maybe its sticking open and when it warms up it dies?

[user101]

I got it fixed, FINALLY!!!

I'm not sure what it was, but I pulled the throttle body off and cleaned it out real good with some carb cleaner and compressed air. I also pulled the injector out and cleaned it out with carb cleaner and compressed air.

While I was cleaning everything I never noticed any obstructions or contaminations.

[kbrown]

Probably a dirty injector.. if ur real careful u can take it apart and there is actually a screen in there you would be amazed at the junk I've seen in them. Also go new but its like 225$