Hard start....

Had a hard time getting her started after the new stator. I thought it was a wiring problem initially until I got it into the garage with the plug out and zip tied to the side of the engine so I could see the spark. I think bad gas was at least part of the problem as it's been sitting since some time last summer. Drained the tank and carb bowl and filled with fresh gas. Still had a hard time starting until I put the muffler tip core back in and wedged a couple screwdrivers in to hold it in place. Even then it shot the core and screwdrivers out when it fired up and would only run with the choke on even after warmed up. Duh!! I changed the backpressure which affects jetting settings required. I didn't think it would change it so much. So I will tack weld the core back in until after my plate inspection, I have a feeling they wouldn't let the extra noise slide anyway... I don't want to get in and rejet until my new wide open carb isolator arrives.

Your old gas could have blocked the carb, you really need to pull it and clean it out.

+1
Clean the carb!

Are you telling us that your piggy is still choked from the factory?

If this is true, your are a Infidel of the power output of the XXR.

Don't forget to complete the choke fix when the carb is off the bike. Don't want to see you chew up the engine.
Then again the engine would still put out the same amount of power as you currently experience.

Infidel!

Factory choked XXR?

Off with your head for being an Infidel.

You really need to uncork and properly jet (pilot jet, main jet and needle) your bike.


Clean the carb or pour a can of Sea Foam in with new gas an run the tank through your bike.
Is your air filter clean?
Is the fuel filter in the petcock assembly clean?

Yes, I changed the jetting a little from stock so it wasn't running lean at least. I figured I would completely uncork and rejet after it was broken in. Well I bought the bike new in 07 and it's still like that. My dirtbike buddys all bought dual-sports, sold their rides or moved far away. I got a BIG dual sport that I rode alot so the dirtbike didn't see a lot of action, maybe once or twice a year outtings. So my XR is basicly brand new, very low hours.

The local shop seemed a little concerned about my muffler when doing a pre-inspection for the plate inspection. I don't think I'll tempt fate by leaving it WFO in the back until after I get the plate. The shop hasn't got my carb isolator in stock yet anyway. It's on order, first things first, get plate, then wheelie time.....

Good point about the choke fix though, hadn't even given it any thought...... And yes, a good carb cleaning is SOP anytime the carb is off the bike whether it needs it or not!

I dug into the carb today a little, just rotated the carb to change the main jet. I had a Dynojet 155 in there from last time and this time I swapped in a 165. It was a little better and I could ride it around the yard without it popping and stumbling as long as the choke was on. Soon as the choke was turned to halfway off it just died even with throttle on. There was some crud in the bottom cap so I may have something plugged in here. I also tried moving the clip from the third slot to the fourth on the needle. Tried adjusting the mixture screw up and down a little too. Things just got worse when I moved the needle clip. I guess I'll need to completely take it apart and clean it out. Couldn't do it today as I was baby-sitting my 3 year old son and 15 year old daughter while changing jets.....

Went from this...

And this....to:


Looks pretty normal at first glance....


Unless you look real hard down the tip..... A little quieter than WFO too but evidently less restrictive than it was before or my jetting would've been right on again with the 155.

In my opinion you really need to do all things together, as pointed out get her uncorked with stock jets and carb isolator, then alter the clip poistion to suit your tip, I ended up setting mine on the 4th position to stop popping under de-acceleration. I was using a modified tip which wasn't as open as the HRC tip I had no popping...along came a HRC £6 delivered of fleabay and popping started; moved clip and all sorted. I have stock airbox cover with no holes and a standard foam filter fitted.
However if your into full bore racing then you will need to ask 1 of the others on here about their set-up.
16211-MBN-640 CARB ISOLATOR 99101-357-1750 #175 MAIN JET
16012-MBN-641 MAIN NEEDLE 99105-MBN-0680 SLOW JET

again +1
But, you MUST clean that carb first....

Yanked the carb off today and gave it some love. Strange thing I found is Windex (or WalMart brand glass cleaner) works awesome for cleaning the dried gas crustys and dirt off the carb. No nasty fumes for my eyes either! (Contact lenses don't like carb cleaner). I found a big lump of crud had clogged the pilot jet (and yes it's a 68s). I put the needle clip back to the 3rd groove. Thought about changing the main jet to a 160 as I semi re-corked the tip, but decided to leave the 165 in and see what I got. After putting it all back together I kicked it a few times with the choke on, nothing. Kicked it a couple times with the choke half on and got a sputter and then she started. Turned the choke off right away and she purred like a kitten. Went down the road and back easy-ish (shorts and tank top helmet gloves and boots) and no popping or anything abnormal.

I had seen pictures of choke plates with a broken off tab in the middle that supposedly gets sucked into the engine causing major problems. What years of XRs had this problem? My 2006 has a spring loaded flapper in the middle of the choke plate evidently to prevent this from happening. Do I still NEED the choke plate upgrade?

DirtyErnie wrote:Yanked the carb off today and gave it some love. Strange thing I found is Windex (or WalMart brand glass cleaner) works awesome for cleaning the dried gas crustys and dirt off the carb. No nasty fumes for my eyes either! (Contact lenses don't like carb cleaner). I found a big lump of crud had clogged the pilot jet (and yes it's a 68s). I put the needle clip back to the 3rd groove. Thought about changing the main jet to a 160 as I semi re-corked the tip, but decided to leave the 165 in and see what I got. After putting it all back together I kicked it a few times with the choke on, nothing. Kicked it a couple times with the choke half on and got a sputter and then she started. Turned the choke off right away and she purred like a kitten. Went down the road and back easy-ish (shorts and tank top helmet gloves and boots) and no popping or anything abnormal.

Glad your sorted and we won't say
"WE TOLD YOU SO" about cleaning the carb so don't worry

But.... if you don't remove that springloaded choke-plate I WILL tell you I told you so!
All years have the same, it must come out.

OK, OK! The choke plate will be replaced soon. Yes I have been warned.....

Yea, especially now that you're going to rip through the hood, plated that is!
Congrats

How hard is it to get the bike to start properly without a choke plate? Right now the spring-loaded flapper has been removed from the stock choke plate so it can not get into the engine. The exhaust tip "plug" has been fully removed leaving the huge 2+" hole, sounds nice. A whole lot of popping going on when coasting off throttle. Not a big deal but maybe an indication of a rich or lean condition? Have'nt pulled the plug to check yet. Just swapped out the carb isolator for the HRC wide open one and changed the jetting up to a 170. (and yes, a 68s too) Before the latest modification the bike would start first or second kick almost always and rarely needed more than choke half on. Do I NEED to buy the aftermarket choke plate? Seems like it should be able to be tuned to start as easy as before without it? Right now I've had to kick it 10+ times to get it to start. A little embarassing when trying to leave work and co-workers laughing as I kick away on a stubborn XR.

OK Ernie, this is what you do for a cold start.
Open tap, close chokelever, pull decomp, do not open the throttle, and cycle the kickstarter a few times, say 3 or 4 easy kicks. This clearly is not kicking/starting so don't worry about the opinion of any bystanders.
Next release the decomp lever, and push the kicker until the engine gets 'hard', it will stop. Then pull the decomp and ease the kicker an inch or so further down, then stop.
Release the decomp, do not touch the throttle, let the kicker come up full, then hammer/whack the kicker down with violence.... done, it'll run. Ease off the choke whilst you feed a little throttle, and off you go.
A warm start is exactly the same but for not using the choke, but I always 'cycle' it first a few times, and it almost always starts first kick.
Finding that hard spot & easing it past it is the trick Ernie, so don't tell your colleagues about it, just do the above.
The men will admire this macho manly procedure whilst the women will admire your developed calve, and may wander their thoughts even further up - if you get it right every time of course, otherwise you'll hear remarks like 'buy a button', 'did you consider a car?' and that sort of stuff

Yeah, I know the starting procedure. But thanks anyway. I may have to screw around with the tuning some more to find the sweet spot. Try moving the clip and maybe changing to a 175 I guess? I wouldn't think the main jet would have too much effect on how it starts though, so perhaps I'll try adjusting the needle clip position first.

Sorry - and sorry also, the needle will have zero effect too, ditto main.
You need to adjust the idle circuit. Here goes.
Ride it warm, park it idling on a stand (not side-stand, bike vertical), and run water from a hosepipe over one radiator.
Up the revs a little bit by means of turning up the slide-screw/stopper. Then turn the mixture-screw to & fro until it starts running badly, and note where these 2 points are. Set the mixture-screw in the middle of this.
Now reduce the idling revs to 'acceptable", and turn the mixture-screw again - but very little this time, also to & fro, also until the revs change. Again set it in the middle.
Switch off engine.
Now turn it fully in whilst you count the turns, until it seats. This should be around 1.5 full turns +/- ~0.5 turn, so somewhere between 1 and 2 full turns. If this is the case set it back, it should be fine from now on.
Try starting it as per the procedure?
However, if you end up with less or more revs (of the mixture-scew) then your jetting is wrong. If less turns than 1 the fule-pilot is too big, if more it is too small.
MIND though, you better be prepared to put yer bock on a clock that the carb is spotlessly clean, especially the airways/holes visible on the intake as well as the engine sides - and I mean compressed-air clean, blown through perfectly. Plus the rest must be spot on, floatlevel, needle & seat etc. The only things which may be off is the main jet & the needle-position.
Hope this helps?

I guess there is maybe two different issues going on. The hard start and the excessive popping during deceleration (which is a non-issue really, maybe just an annoyance). But yeah I thought about the needle thing after posting and that was a brain fart....

Aaaaaa, hold on a sec: idle the bike whilst you wave a gasburner (OFF, gas only, no flame) around the inlet rubber.
If the revs pick up you've got an airleak.....

Sounds like a good idea, seeing as I just replaced the isolator/boot that sounds like strong possibility. I'm going to clean the filter and check the spark pllug while I'm at it. I think I will have to get the aftermarket choke plate too. Was that an XRs Only item? Tried to ride it to work yesterday and after kicking for the bike for 10 minutes with no luck I took my truck instead.

Black sooty sparkplug and exhaust tip. I'm pretty sure this means I'm running rich. If I had a boot leak I think it would be the other way around. So no, I didn't try the gas torch trick yet. I tweaked the mixture screw back to 1 3/4 turns out kicked her over and put a water hose trickling over the radiator. Turned the screw in until the rpm's dropped noticably then back out 3/4 turn. Sound right? Started repeatedly (first kick) without issue, but the bike is warmed up and it's about 100F out right now. I guess I find out if I need to adjust more in the morning when everything is cooler. Fingers crossed I can start riding it to work again during the week as well as playing on the weekend....

Turned the screw in until the rpm's dropped noticably then back out 3/4 turn. Sound right?

No, not at all - don't back it out "3/4 turn" but back it out until the rev's again drop/differ/whatever, and then set it in the middle of these two settings, like I said.
And this final setting should be 1.5 turn +- 0.5 turn from closed. If it's more or less then your jets (idle jet most probably) are wrong, and you'll have to change those.

I agree, your boot will seal, no gassing required.
But, got a foam filter? Possible is that there's way too much oil in it, quite common actually. Press it between dishwash cloths until it does not give off oil anymore - then it will be correct.
Also, got an 'open' sidepanel? If not, have you got some stuff/rubbish mounted in the way of the airflow, say a battery mounted in the 'gulley' behind the ignition module under the saddle? This is a bad idea mounting stuff there, as this is the main airway through which your poor pig breaths, so if so you'd best mount an opened sidepanel. But try if this makes a diff by taking it off when warm & idling - any difference? I yes then you've found a no brainer...

I turned the mixture screw out until I thought it was going to fall out of the carb with no noticable change in rpms. Don't know what that means? I think it was at least 4-5 turns out and still no change! Maybe time to take the carb off again and check for crud and crusties.

I just cleaned the air filter and made sure to sqeeze all the excess oil out. No problem there, but you bring up a good point about the stuff under the seat.