[449.4R]

I spent most of the day going over the things I found from searching-
Will only idle with the choke on would be a lean or clogged pilot circuit.
I pulled the pilot out 3 times, its not clogged and can see light.
Theres no debris in the float bowl, and lots of gas comes out so fuel is def there.
Im wondering if I need to step up the pilot size?
I figured JD would have reccomended a bigger pilot if needed?
Both boots to the carb have been checked all day, they are tight and oriented correctly.
As for exhaust leaks everything is tight and checked.
The fuel screw does not make a difference when turned either way, but the oring does look tired.
Also the idle screw has no effect and now im afraid ive lost where its supposed to be set at with all the tweaking and trying.

Really all im left with is "bad gas" but that would be a long shot.

It wont even try to idle. At 1/4 throttle or so it will pop and bang super loud if reved and like I say f/s adjustment wont even it out.

Any help greatly appreciated guys. TIA

My specs-

450r
JD red 5th pos
175 main
42 pilot
1 3/4 out
Home is about 200ft but ride at about 3000-5000 ft

[Asmith]

Has the slide been removed from the carb...ever?

[449.4R]

I dont believe so. Only the top cover was taken off for the needle switch. Thats it.
Oh and the AP cover was taken off for the o-ring mod.
But its def not a situation where jetting was just done and now wont run right. Forgot to mention-

The current jetting has already been proven with several rides with the exception of the current weather.
The last time it was ridden toward the end of the day It started backfiring on decel so hard that it couldnt be ridden.
And I dont mean an average "lean decel pop" I mean violent gunshots and then got to where it would quit at idle.
Out of nowhere!
I have since changed to a different fuel screw to let me make easier adjustments and I did notice the oring is tired.
Not sure how inacurate that could make the setting, but it wont get better in any position.
(and yes it has spring/washer/oring in that order)

If anyone has any similar situations or ideas please tell. I have the day to try to get this sorted out.
My friend just got his head back from ~ and now im the one thats not ready to ride....

[Asmith]

The 450R really benefits from a 45 pilot.

I know you removed the pilot and can see light through it. Did you put a small gauge wire through all the orifices??? They can be clogged with a grain of sand and since sand is translucent, light will shine through.

If you clean the pilot well, with a wire, and that makes no difference, try a 45.

[449.4R]

yeah it cant get any cleaner, its been soaked poked and blown out with air.

I will try the 45, but I dont think I can get it today though....

Thanks!

[449.4R]

After looking around awhile I hardly notice any 450s using the stock pilot.

Wonder why its not in the kit or even mentioned?

[Asmith]

yeah it cant get any cleaner, its been soaked poked and blown out with air.

I will try the 45, but I dont think I can get it today though....

Thanks!

Soaked, poked and blown...maybe you are just spoiling it...

[449.4R]

[449.4R]

I can only find a 48 pilot.
I know going from 42 to 48 is a big jump.
Would this be ok? Can I compensate with fuel screw?

I still have other mains and can change the clip pos if needed.

[Asmith]

I can only find a 48 pilot.
I know going from 42 to 48 is a big jump.
Would this be ok? Can I compensate with fuel screw?

I still have other mains and can change the clip pos if needed.

I run a 48 in my bike. I have the fuel screw at 1 3/8 to 1 1/2.

It should work, might be a touch fat but it should serve to diagnose if the pilot is the issue.

[449.4R]

awesome thank you. I'll let ya know.

[bamm]

i just went through same issues with my 450r, only my problem was my jetting was too fat with my sound insert in....so anyhow i fixed it but was still not idling and would stall at low speed, went up to 45 pilot, fuel screw 1 1/2 turns out and its on point

[449.4R]

picked up a 45 and a 48.

Install 45.
Start with fuel screw at 2 turns out.
Runs with choke, push in choke will not idle period.
When gets up to temp will not kick w/choke- understandable.
Try fuel screw anywhere from 1.5 to 2 1/4 kicking w/no choke, no change.
Will only run at like 1/4 throttle so I cant even tell what reaction my adjustments are making.
Same with idle, I have completely lost where I need to be with the idle screw. But I figure its not too far since choke rpm is decent.

Im furious. haha
Right now I cant handle trying the 48 only to get same results.

Suggestions where I go from here?

[[email protected]]

A bike that ran great does not suddenly need a pilot size change unless conditions are drastically different, ever.
The JD needle is a lot richer down low, so a 42 pilot is fine almost always. Always in your case, because it did run fine before, right ? Put the fuel screw and idle screw about where they were.
This is a pretty simple thing to figure out because those symtoms only have a few causes.
1.A dirty pilot jet/dirt in the float bowl, which I know you know all about.

2.The plate on the carb slide the guys mentioned being upside down, the hole in it goes to the bottom.
3. The fuel screw fell out, or the order of spring/washer/o-ring on it was messed up.
4. Rag left in airbox.
5. Bad plug. Very rare.
Now, what brought about working on the bike at all ?
If suddenly it became hard to start, and/or you were riding, all was well and it started acting weird go back over the stuff we mentioned.
No luck ? Make darn sure you are at compression tdc(you can get a little "tick'tick' by shaking the exhaust tappet after all is lined up), then measure your intake valve clearance and let us know what you get before doing anything. Doug

[449.4R]

Replys to your checklist-
1. Confident the carb bowl is clean and using a new pilot.
2. I will check the slide but dont believe it to ever been removed.
3. F/S is in right order, but like I said the oring is lil smooshed. No leaking though.
4. I was actually wondering about my filter being over oiled. For now I have a fresh one in with no oil on it.
5. Your right plug s/b fine.

I didnt think it just needed to be fine tuned or anything.
It was obviously getting worse and by the time a few hours went by it was in a bad way.
That day it would always start for me even hot, but was running rough and got progressivly worse with the gunshots.
At the time It seemed like just a slight turn of the fuel screw would even it out.
So I ordered a new one that way I could give it a 1/4 turn here or there when the motors hot.
That was some time ago, but now I have the time to deal with it.

I would be suprised if its valve clearance.
It has about 4 rides on a new piston/rings and also new chain/tensioner.
At that time the clearances were well in spec. (Stainless valves)

I have no problem checking again.
It almost seems like it might have skipped a tooth or something.
Although Im not sure how that would be, thats what it seems like.

I appreciate the help. Thanks.