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Cjcampbell

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Reply with quote  #1 
I have a 2008 outlaw 525s with the CFM Airbox and hmf exhaust . Just bought off my brother. Hadn’t ran in a while but he said he thought it needed decompression lever replaced as it was hard to turn over. Had valves done at the ktm dealership now it turns over easy as pie so that problem was resolved. Now Ibput the CFm airbox on and it won’t start. It was running a 138 main jet with the stock airbox and hmf exhaust slip on . It would backfire through the carb a lot . I assumed it was lean since I put the higher flowing airbox on. I got a 155 main, 162, 170,175 from the local shop. Tried the 155 and 170 so far with no luck. I’m going to change out spark plug in morning and mess with card some more. Any suggestions ? It just cranks but when I pull choke it Boggs down. When I give throttle it tries to start but dies. To me that seems like it is rich but I’m not great with this stuff so any help is appreciated. I live near Pittsburgh Pa for elevation. Cold temps coming
TxOutlawRider

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Reply with quote  #2 
I don't have any experience with the "S" models, or the CFM boxes, I can tell you that the box should have no influence on the quad starting.  It should start right up and idle without any kind of box or filter connected. 
  As for the hard starting... check to see if your accelerator pump is working.  It may be plugged or the diaphram is bad.  It can also cause allot the backfiring once its running.
  Id tell you to check your valve lash, but I have to assume the KTM shop did that already. 

  The jetting, I can only assume that you still have the stock needle,  I would start by moving the needle clip down 1 notch (it will raise the needle).  Then I'd guess a 155 or 160 would be the most that you'll need with the CFM box. 

   Good luck and congrats on your new ride. 

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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
Cjcampbell

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Reply with quote  #3 
I checked accelerator pump. Cleaned out with cleaner , appears fine. One problem I realized is I was taking the throttle sensor out of carb and not just unplugging it. Also needle was adjusted for exhaust years ago. Needle is on 4th clip from top (middle notch, fourth from top also)
TxOutlawRider

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Reply with quote  #4 
I've messed with homebuilt intakes on my IRS using pipe and open lid so it should be similar to your CFM box.  I believe the IRS was stock with a 148 main jet and with the old HMF and homemade box I think I ended up with a 155 main and raised the needle one position. 

Be careful using that carb cleaner around the throttle plate or the accelerator pump diaphragm.  The throttle plate has a rubber ring inside that will swell up, and the pump diaphragm can break down. 


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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
Cjcampbell

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Reply with quote  #5 
Thanks for the help guys. I got the sensor readjusted and cleaned carb . Put on and took the little slack out of the accelerator pump screw adjustment. I put carb on and have fuel flowing to carb. No airbox on. When I turn throttle I’m looking in carb and do not see the squirt of fuel from the accelerator pump. This has to be the problem. (From what I see) I should have that squirt as the slide lifts up and I do not have any squirt. I can spray starting fluid or squirt of fuel in car. And it starts for a second so I’m thinking this is my culprit. I had the accelerator pump cover off but the diagram would not come out and I was afraid to damage it with a tool. I may have to tear it out though.
TxOutlawRider

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Reply with quote  #6 
You can order those diaphragms from JD Jetting or several places on the web.  They came in 3 or 4 different "lengths".  The longer the little post is on your diaphragm the shorter the pump shot duration.  That may or may not be a good thing.
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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
TxOutlawRider

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Reply with quote  #7 
Its a long shot, but something else you might check is making sure the float needle valve isn't binding or the floats hanging up and not letting the bowl fill up.  It should be easy to tell as there wont be any, or very little, fuel in the bowl when you open the carb up.  If the bowl doesn't fill up, the accelerator pump wont work... it also wont start or run. 
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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
Cjcampbell

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Reply with quote  #8 
Update: fixed up accelerator pump and it’s working good. Put a 155 main in . Left same pilot and starter in that was in with stock airbox and hmf exhaust . (No legible numbers ) found blockage in mixture screw. Cleaned it and set at 2.5 turns out. Accidentally moved clip on needle up 1 instead of down 1(oops) . Put back together and it starts up and runs when giving throttle. Backfires though and dies when I let off throttle.(no idle) I will have to take needle back out and move back down 2 now. Is there anything you see that I need to change. I’m getting tired of taking this thing out of quad and would like to make any changes in one shot. I’m not sure what the idle screw is set at. Haven’t messed with it
TxOutlawRider

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Reply with quote  #9 
The airbox shouldn't need any changes to the pilot jet size. A flexjet mixture screw can really save you time when you're setting the idle mixture. After you get the needle where it's supposed to be then you may find the popping goes away.
If it we're me, I'd leave the airbox off until I got the idle fixed. It would save you some time.

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2007 Outlaw IRS

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Cjcampbell

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Reply with quote  #10 
Fixed the needle. Now on 4th ring down. Still backfiring a little and won’t idle without throttle. I ordered the flex jet mixture screw. Would putting a bigger main jet in help also? I assume it’s running lean. Is this a correct train of thought if it runs when I give it throttle? I have A 155 in now but also have a 162 , 170, and 175 on hand. I appreciate all the help I’m no expert just a learn as you go type person so I’m trying to really learn from you and not get frustrated with the lack of idle.
TxOutlawRider

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Reply with quote  #11 
The main jet only changes the mixture from about 3/4 throttle to wide open. If it doesn't idle it's the pilot jet or pilot air jet. Did you remove the throttle plate by any chance?
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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
Cjcampbell

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Reply with quote  #12 
No I didnt remove it. The screw that holds it in is stripped and I was nervous to try. As for the pilot jet. I’m not sure if the size. It was the one that was in it with the stock airbox and hmf exhaust
TxOutlawRider

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Reply with quote  #13 
Are you sure you didn't just turn the idle speed screw out too far?
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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
Cjcampbell

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Reply with quote  #14 
Perhaps. I turned it out 2.5 revolutions. Do you suppose that is too much?
TxOutlawRider

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Reply with quote  #15 
There's an idle speed screw that's connected to a cable and is connected to the side of the carb, then there is the idle mixture screw that is in the carb body and points straight down.
Turning the idle speed screw clockwise speeds up the idle. I'd keep turning it in about 1/2 a turn at a time until it idles.
The mixture screw is something that you tune the mixture with after you get the idle speed pretty close. 2.5 turns should be in the ballpark to get it going.

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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
Cjcampbell

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Reply with quote  #16 
I had the fuel mixture screw at 2.5 turns out. I’ll put the carb back on and mess with the idle speed knob then. I ordered the replacement flex screw for the mixture screw.
TxOutlawRider

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Reply with quote  #17 
Also, be sure that when you removed the idle mixture screw that you got all the parts out with it.
  There should be 1) the screw, 2)a spring, 3) a small washer, and 4) a tiny o-ring.  If you don't get all the parts out when you removed the screw to clean it you can get the o-ring shoved in sideways and lodge it inside the passage way when you reassembled it.  Or if you lost the o-ring or the washer and you reinstall it without them, it wont idle.  
 

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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
Cjcampbell

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Reply with quote  #18 
All parts to mixture screw are accounted for. I got the throttle slide out and I see a little wear on the edge of the vacuum seal . Would this cause the issues?
distraction628

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Reply with quote  #19 

Have you checked your ETC in the throttle housing to make sure you have a gap between the points in there? Just asking because a lot of people take out to much slack when the put the carb back in.  This will cause idle running problems some times.  Also the carb to head boot get cracks in them and can cause a ton of running problems.   If this has already been covered , I just don't have time to read everything on my phone.

Hope you get it corrected asap.


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07 525, 06 500, 10 525s 09 RZRs, 04 Ram 2500 Cummins 6spd, 08 Fuzion toy-hauler
TxOutlawRider

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Reply with quote  #20 
As Distraction said, check the boot that goes from the head to the carburetor for tears and cracks as it does happen, especially if the carburetor has been removed several times and the clamps weren't completely loose. 
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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
Cjcampbell

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Posts: 23
Reply with quote  #21 
I ordered a new o-ring/seal for the slide plate and the flex jet mixture screw. They should both be here by Monday. I will go over the boot good and inspect everything. This carb is becoming a real pain!
Cjcampbell

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Reply with quote  #22 
Boot looks good. Can you elaborate on the etc in throttle housing? Are you meaning the throttle cable adjustment or the accelerator pump adjustment? One other thing I noticed is there is some play in the throttle plate. Little wear on inside of carb where wheels run . Could it be sucking extra air around the slide giving me troubles?
distraction628

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Reply with quote  #23 
Open the top of your thumb throttle housing, inside is the etc points, there has to be a gap if there isn't adjust your throttle cable until there is. Then start your quad and adjust idle to 1800 . The FCR is one of the easier carbs to work with. If it has been neglected, then I would get a full kit for it.
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Cjcampbell

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Reply with quote  #24 
I will do just that. Thanks for the help. At this point I have replaced everything the kit comes with separately. Waste of money but oh well
TxOutlawRider

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Reply with quote  #25 
I really think its something simple.  Dirt in the jets or something, or maybe the idle speed is just too low.
  The throttle plates will usually show some wear but it doesn't seem to affect the performance of the carburetor. 

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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
Cjcampbell

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Reply with quote  #26 
Idle may of just been too low but I doubt the dirt . I have had everything off this carb and cleaned it over and over. When I get the two parts I’m waiting on I will hit it hard and double check everything. I’m hoping it is running soon.
TxOutlawRider

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Reply with quote  #27 
If you went 1/2 the country away, I'd come by and help you.  lol
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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
Cjcampbell

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Reply with quote  #28 
Thanks! Not a lot of people would be willing to lend a hand especially now that it is getting cold...
But I appreciate all the help you have been giving me on here.
Cjcampbell

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Reply with quote  #29 
Any particular type of grease to use on the throttle assembly?
Cjcampbell

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Reply with quote  #30 
I got new parts on carb and got it in with the 162 main. Adjusted mixture screw out to 2-1/4 turns . Adjusted idle to where it tries idling. It is so damn close . Iittlest bit of throttle and it stays running. Sounds good with not much backfiring . Idles better with choke on though. Contacts in throttle are not touching. The racing tether is removed and wires are not touching each other. I did notice it idles when I put my hand over intake to limit air going in.so I put the airbox in with the lid thinking it would help limit the air a little. But it still does the same.
TxOutlawRider

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Reply with quote  #31 
Quote:
Originally Posted by Cjcampbell
I got new parts on carb and got it in with the 162 main. Adjusted mixture screw out to 2-1/4 turns . Adjusted idle to where it tries idling. It is so damn close . Iittlest bit of throttle and it stays running. Sounds good with not much backfiring . Idles better with choke on though. Contacts in throttle are not touching. The racing tether is removed and wires are not touching each other. I did notice it idles when I put my hand over intake to limit air going in.so I put the airbox in with the lid thinking it would help limit the air a little. But it still does the same.


Be sure the quad is good and warmed up, Id say let it run 10 minutes at least.  If it still like likes to idle better on the choke, then try turning the mixture screw out another 1/4 or 1/2 turn and see if it idles better and the popping quits.  If you get to 3 turns, and youre sure theres no vacuum leaks, then go up 1 size on your pilot jet and reset the idle mixture screw out about 1-1/2 turns and try it again.  It sounds like youre getting close.

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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
Cjcampbell

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Reply with quote  #32 
Turned out mix screw to 3 turns and idles without choke. Runs like a raped ape too. Thanks for the help
distraction628

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Reply with quote  #33 
You better go up  one pilot, or you might find the mix screw falling out at 3 turns.... then you can be at 1.5 to 2.25  turns.... Ive seen it before.....
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07 525, 06 500, 10 525s 09 RZRs, 04 Ram 2500 Cummins 6spd, 08 Fuzion toy-hauler
Cjcampbell

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Reply with quote  #34 
The problem is I’m not sure what size this pilot jet is. The carb was jetted with the jets that came with the aftermarket hmf exhaust. Not sure which ones where changed though as I’m not the original owner. He said jets were changed acccording to the hmf recommendations.he thinks it was just the main but not 100% sure .The pilot jet has no markings on it to indicate size but it is possible it is the stock size.
TxOutlawRider

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Reply with quote  #35 
Ive never seen one that wasn't marked, that's weird.  Its been so long since my carb was stock I don't know what the stock size would be.  Im guessing a #40 or #42? 
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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
distraction628

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Reply with quote  #36 
2008 525s had a 45 pilot, so get a 48 and 50
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07 525, 06 500, 10 525s 09 RZRs, 04 Ram 2500 Cummins 6spd, 08 Fuzion toy-hauler
TxOutlawRider

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Reply with quote  #37 
Just out of curiosity, does the CFM box just use a round hose to connect the carburetor to the box or does it use the factory connector?    I only ask because if its just a hose you might want to look into a transition ring for the carburetor in the future.


http://shop.fuelcustoms.com/product-p/ac003.htm

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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
Cjcampbell

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Reply with quote  #38 
Sorry for the delay guys. I had it running good but it would bog and die occasionally so I assumed it wasn’t getting enough fuel at the previously stated settings. So I picked up a 48 and 50 pilot and put the 50 in. Now with no airbox on it won’t start. The one starts when I limit air flow to carb with my hand. Is this a sign that there is too much fuel going into the carb? I did find a 45 marking on the pilot I took out.

* put the 45 back iN ....
TxOutlawRider

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Reply with quote  #39 
Check your accelerator pump first.  It it spraying good and hard and just missing the throttle plate.

Once you get it started (with your hand choking the intake) can you remove your hand and will it idle?

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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
Cjcampbell

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Reply with quote  #40 
Accelerator pump looks perfect. When I remove my hand it dies
TxOutlawRider

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Reply with quote  #41 
That's usually the sign of it being lean.  Check the intake boot (between the carb and head) for leaks.  Its not unusual for them to crack and leak... or maybe its just loose. 
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distraction628

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Reply with quote  #42 
Ok when you put your hand in front of the carb, you are restricting air flow, so you are making it richer!
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Cjcampbell

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Reply with quote  #43 
The intake boot looks fine. I should think that with the 50 replacing the 45 pilot that it should be running richer without me restricting air flow?
Cjcampbell

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Reply with quote  #44 
I thought changing the pilot from 45 to 50 would let it run richer with the higher flow of air but it didn’t help and acted like it was getting too much gas
distraction628

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Reply with quote  #45 
The 50 is richer, Maybe someone drilled tour 45. How many turns out is your pilot mix screw? It should be about 2. Put the 48 in it.
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07 525, 06 500, 10 525s 09 RZRs, 04 Ram 2500 Cummins 6spd, 08 Fuzion toy-hauler
Cjcampbell

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Reply with quote  #46 
It was 2.5 turns out, but I closed it and tried 1.5, 2, 2.5 and 3 but none worked. I have to work doubles next two days but when I get time I’ll try the 48 at 1.5 to 2 turns out and see how it goes . I’m getting to the point where I’ll take it to the shop to let them dial it in. I feel so close but it is beginning to break my spirit
TxOutlawRider

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Reply with quote  #47 
I would think you'd need a 42, 45, or 48... the 50 should be way big. 
Also check your float level.  A low float level will create a lean condition. 

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2007 Outlaw IRS

"Outlaws are the Chuck Norris of the quad world."
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