04' bogs/stalls on starts

[sunco]

Mines all stock. At times when I'm ready to start my ride - I throttle & it craps out. Whats up? What can I do to make it get up & go. W/O adding a pipe.
Out of sight = Out of mind.

[MR.BIG]

Most likely you have dirt in your pilot jet so clean your carb and make sure you air filter is clean too.

[gbcap]

i was going to say the same thing. clean the carb, clean the filter. if your problem persists, play with the idle adjust, that helped me fix a few running problems before.

[sunco]

Great - thanx for the help.

The idle might be to low.

[sunco]

should I turn my idle up 1st? Never done the carb. It would be the 1st time. If I did the carb would/should I un bolt it & then clean it or can it stay mounted & spray it w/ carb cleaner?

[ckasper18]

Take it iff to clean carb its pretty simple fix if your mechanically inclined.............

[DirtDevilBT]

don't turn your idle up to fix something, especially on a stock quad. Have u been able to ride it without a problem, and now it's craping on u? Or has this always been a problem? Is it new, or did you just buy it off someone? etc etc

[sunco]

I am the original owner. It's more lately but it's happened in the past.

[Z-135]

Cut a 2" hole in the back of the air box and take out the baffle and put in a 155 main jet. This will make a big difference!

[DirtDevilBT]

That will make a difference but not where he needs it. ^^

Does the idle seem low to you? If so then an adjustment might be in order. If it seems normal then a fuel screw adjustment might be needed. If you already have tried that, then a carb cleaning is in order.

Sometime there is a lot of crap in a carb even when it is brand new.

[adinocr7]

My 06' TRX 450R was bogging badly and would even stall if you really slammed the throttle from an idle. I ordered and installed a #55 leak jet from Magicracing.com (http://www.magicracing.com)

The thing has no bog what so ever . . . it did the trick.

[GPracer2500]

Originally posted by adinocr7
My 06' TRX 450R was bogging badly and would even stall if you really slammed the throttle from an idle. I ordered and installed a #55 leak jet from Magicracing.com (http://www.magicracing.com)

The thing has no bog what so ever . . . it did the trick.

The right move for an 06'. Unfortunately it doesn't apply to the 04/05 carb.

Nice link for Magicracing though. How was their shipping cost and shipping time?

[GPracer2500]

Most likely this is an Accelerator Pump issue. Assuming 1) carb is clean 2) pilot circuit is correctly jetted 3) idle speed is appropriately high then the only thing left to do is to tune the AP. Unfortunately the 04/05 450r carb has no standard adjustment points for the AP (arghhh!).

I wish I had one of these carbs to play with. Usually there is a way to "mod" an AP without standard adjustment points to get it to perform. But for any of you folks out there that feel up to it, take a look at this pic of the AP lingage (this is under the black plastic cover on the side of the carb)....

http://img177.imageshack.us/img177/559/0405aplinkagegu0.jpg

Arrow #2 is pointing to the top of the rod (under that little black accordian boot) that pushes down on the AP diaphram. The diaphram is what forces fuel out of the AP squirter. Arrow #1 is pointing at the tab on the AP linage arm that pushes on the AP rod.

When the throttle is fully close check to see if there is any space between that tab (#1) and the AP rod (#2). If there is a gap then the AP is not being activated immediately upon opening the throttle and that could be part of the problem....

....So, if there is a gap of any size the first thing I'd try is to eliminate that gap. I'm thinking either shimming up the space with glued-in spacer or just bending the tab. I'm not saying for sure that's the solution; but for someone wanting to experiment the above would be a place to start.

Just a thought.

[Scro]

Originally posted by GPracer2500

....So, if there is a gap of any size the first thing I'd try is to eliminate that gap. I'm thinking either shimming up the space with glued-in spacer or just bending the tab. I'm not saying for sure that's the solution; but for someone wanting to experiment the above would be a place to start.

Just a thought.

I'll try that tonight...thanks!

[adinocr7]

GPracer2500: That is awesome advice. Now you mentioned that the 04/05' Hondas do "not" have an adjustment point on the AP. I have a 2006 . . . does mine have an adjustment? If so I'll check it out today. I also have a full Service Manual so I'll check the pictures in there.

Thank you again,

Adam

[Scro]

Originally posted by bama450r
I'll try that tonight...thanks!

I tried it, and it actually made it worse. Could that mean that I am too rich on the pilot?

[GPracer2500]

Originally posted by bama450r
I tried it, and it actually made it worse. Could that mean that I am too rich on the pilot?

Possibly. But you really wanna confirm the pilot circuit is correct/incorrect using the proper way (http://www.exriders.com/vbb/showthread.php?s=&threadid=229923). The engines gotta be running while you adjust the fuel screw. It's a pain to get to the screw without a 90 deg screw driver but there's not really an easy way around that. Otherwise you're mostly just guessing. That's not to say that low end throttle response shouldn't be a guide to tuning the pilot circuit, but you'll never get anywhere unless you know you're at a "correct" starting point.


So there was a gap? How big? What exactly did you do? Have you made any observations of the squirt in action? The reason I ask is because if squirt starts too soon then it can hit the slide before it has a chance to move up and out of the way.

Hmmmm....

[Scro]

Originally posted by GPracer2500

So there was a gap? How big? What exactly did you do? Have you made any observations of the squirt in action? The reason I ask is because if squirt starts too soon then it can hit the slide before it has a chance to move up and out of the way.

Hmmmm....

Yes, there was a significant gap between the tab and AP rod. I bent the rod down just enough, so that it was barely touching. How can I check to make sure the squirt is not hitting the slide?

[GPracer2500]

Originally posted by bama450r
Yes, there was a significant gap between the tab and AP rod. I bent the rod down just enough, so that it was barely touching. How can I check to make sure the squirt is not hitting the slide?

Remove the air intake so just the carb and nothing else is connected to the engine. The goal here is you want to be able to look straight into the carb. Or you can just remove the carb--but hook it up to a fuel source.

Look into the inlet side of the carb. You'll see a little tube sticking into the carb's throat. That's the AP squirter. You should see a raw stream of fuel squirt out of it when the throttle is opened quickly. You want the stream to just miss the bottom of the slide as it slides up and out of the way.

If you leave the carb on the bike you don't have to have the engine running.

[GPracer2500]

Off-idle bogs can occur from too much AP squirt, to little squirt (this is the common case), or a squirt that's too soon or too late.

If there was a big gap and you closed it up completely then it's possible that was too much. Maybe try only closing that gap half-way and see what happens.

[Scro]

The squirt is just below the slide, but it is also squirts very close to the bottom of the carb. Is it supposed to shoot up a little, or just straight out:confused:

I adjusted the idle speed per your writeup, but it stills bogging. Also, I noticed that when I stab it fast enough to make it die, it sort of backfires through the carb or sounds like it any way.

[GPracer2500]

Just missing the slide is where the squirt should be. I'm not sure about the height or angle of the squirt. Since that carb has a butterfly in addition to the slide it probably needs to stay low so it clears the butterfly.

If the bog was worse with that gap closed then I'd try leaving just a small gap. If it's still worse then go back to where you started (just to re-affirm the status of the original condition), and then try widening the gap and see what that does.

Without seeing for myself exactly what the changes are doing to the squirt I'm really just guessing about what needs to be done.

[GPracer2500]

Originally posted by adinocr7
...I have a 2006 . . . does mine have an adjustment?...

Yes. You've got an AP linkage screw that can be adjusted and also have a leak jet. The linkage screw is for adjusting the squirt timing while the leak jet adjusts the duration.

[sunco]

Thanx for all the good info. I haven't had time to read all yet . I was at breezewood for labor day. The bearing for the carrier broke the last day so I got alot of work to do in the shop to get things going. I learned alot this weekend. I'll share later.