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Tricks to fix the flame-out on 2009-2012 CRF450s

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I am looking to see if anyone as found any good tricks for reducing flame-out which is a pain in the ass on 2009-2012 CRF450's. I am looking for engine tricks that adress the actual cause rather than bandaids like a heavier flywheel or lower gearing.

By flame-out, I think I need to clarify what I am talking about as many beleive it it referes to different situations. I dont mean stalling at low speeds or when closing the throttle or when locking up the rear wheel or backfiring out the exhaust.

By flame-out, I mean when the engine quits when you crack open the throttle... it happens when you grab a handefull of throttle when the engine is at low rpm and the throttle plate is initially almost fully closed. From what I heard is that at low rpms with the throttle plate almost fully closed, the fuel gets to the spark a split second before the fuel, as well as the fuel being pulled i by the low pressure along the walls of the throttle body from the almost fully closed throttle plate, and the fuel blows ou the spark before the air can get there. It totally sucks when you are about to jump a big obstacle coming out of a slow tight turn and she just dies and leaves you there kicking the enginee over in a race.

The bike already had Tokyo Mods fuel and ignition mapping (did nothing to help this particular problem), FMF 4.1 slip-on, the HRC fuel injector trick, and one more tooth on the rear sprocket. Idle is set at 2000+ rpm.

This is what I have done so far to get more air to the combustion chamber faster;
1. removed the airfilter backfire screen
2. did the Dave Simon choke mod
3. rerouted the valve cover vent line from the airfilter box to an external filter so the engine only breathes fresh air
4. added a Moto Tassinari Air4orce air boot with the long velocity stack which should improve air speed at low rpm according to my discussion with the manufacturer

I heard a hotter spark plug would help, but a cant find a hotter one, only a cooler plug that fits the CRF450.

There is a few feet of snow on the ground so cant see how these mods improved the problem, but I wanted to see if any of you guys found any good solutions for this really annoying problem with this engine.

thanks,
mike
Edited by Tokyo_Tiddler

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What you describe isn't normal. I have raced my 2009 for the last four seasons and only when it was brand new did it flame out a couple times during off throttle situations. I would start with a high idle and see if that helps.

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Tokyo,

 

Sounds like it could be a couple of things..

 

1) The idle may be too low.. should be set @ 1,750 +/- 100 rpm. (IAW 09 450R Owners Manual and Service Manual)

 

2) Possible ECU mapping issue. (Have you ever had the ECU remapped.?)

 

3) Possible dirty fuel filter @ fuel pump.

 

I've never had that problem with my 09 450R.. had Eddie Sisneros remap the ECU several times to keep up with changing engine mods. Crisp off the throttle from idle. (No bog/fade)

 

Good luck.

 

 

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Thanks guys.. I think you didnt read my original post fully.. I have already done the remapping with Tokyo mods and have idle at 2000+ rpm..  The only thing I didnt mention was that this is a brand new bike.. I bought it as a leftover of the dealer floor and it has only 3.5 hours on it so far. I hear it does improve somewhat with time.  I have heard others mention the same issue and Dave Simon has a video re. this very issue.

 

mike

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Hi Mike, I am having a similar issue with mine. If trails are fast, works perfect, my issue is in 0-5 mph stuff on and off throttle, it can flame out when you crack the throttle.

I am going to use the HRC tuner and make the changes Dave Simon reccomended. (as you already referenced)

Drop fuel by 5% at 5% throttle and 3% at 10% throttle. and leave the rest alone (for now anyway). Dave said that works!

Btw you also made the choke plunger mod, did you use a cork as Dave suggested?

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Haven't spoke to him in a long time, but Wade Wilcox? With injectioneering did my 09 and it was night and day. I used it to race hare scrambles and it worked pretty close to perfect after that mod. Also, someone mentioned fuel filter. This was an issue with mine as well. Be sure to get the latest superceded fuel filter as they seemed to work the best. Hope you get squared away. Mine was frustrating at first but ended up being one of my favorites.

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A plus 11 flywheel is the answer.

The 13 went to a heavier flywheel.

Have you seen the stock flywheel its funny.

It doesn't hurt performance what so ever.

It's no a cr125 that needs 12000 rpm clutch dumps off of every corner.

Edited by englertracing

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Hi Mike, I am having a similar issue with mine. If trails are fast, works perfect, my issue is in 0-5 mph stuff on and off throttle, it can flame out when you crack the throttle.

I am going to use the HRC tuner and make the changes Dave Simon reccomended. (as you already referenced)

Drop fuel by 5% at 5% throttle and 3% at 10% throttle. and leave the rest alone (for now anyway). Dave said that works!

Btw you also made the choke plunger mod, did you use a cork as Dave suggested?

yes, I used the 1/4" cork and super glued it in.

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A plus 11 flywheel is the answer.

The 13 went to a heavier flywheel.

Have you seen the stock flywheel its funny.

It doesn't hurt performance what so ever.

It's no a cr125 that needs 12000 rpm clutch dumps off of every corner.

The powerband is alread too hitless for me for MX.. not a huge issue but I value throtle response above anything... and by laws of physics, it has to slow down the response a little, so that is why I wanted to address the issue rather than band aids.

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Haven't spoke to him in a long time, but Wade Wilcox? With injectioneering did my 09 and it was night and day. I used it to race hare scrambles and it worked pretty close to perfect after that mod. Also, someone mentioned fuel filter. This was an issue with mine as well. Be sure to get the latest superceded fuel filter as they seemed to work the best. Hope you get squared away. Mine was frustrating at first but ended up being one of my favorites.

I would do the injectioneering mod in a heartbeat if I didnt hear about all the nightnare stories recently.about people getting screwed and not gettingtheir throttle bodies back.

 

I have had a splitstream tank filter in the tank since new. I dont think that is the issue... bike is brand new and has done it since the very first ride.

Edited by Tokyo_Tiddler

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I would do the injectioneering mod in a heartbeat if I didnt hear about all the nightnare stories recently.about people getting screwed and not gettingtheir throttle bodies back.

 

I have had a splitstream tank filter in the tank since new. I dont think that is the issue... bike is brand new and has done it since the very first ride.

 

 I hadn't heard that about Injectioneering, if so that really sucks. Wade seemed like a pretty good dude. Another one of those places you call and actually speak to the guy; hard to find that anymore.

 

I had a split stream as well before I put my IMS tank on, it doesnt work now beacuse of the larger diameter fill neck which is a bummer because that thing was pretty slick.

 

As far as mapping, (just in case you end up wanting to try something other than tokyo mods) Ron Hamp is another very reputable source. He is on here all the time and does a lot of motor work as well as mapping. I just got mine back for my 13 and it turned out really well. A search for Ron Hamp cycles gets you his contact info. He may be able to help point you in the right direction either way, who knows.

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Injectioneering fixed my 2010 yz,the stories are old & BS .He never stole anybodies stuff.Did you remap before or after removing backfire screen? Removing my screen made mine lean & needing a remap.If you have to pay for a remap ed's $50,tokyo's $75 +shipping.Injectioneering mod to the throttle body costs around $200+ its good, but I think ed can fix you up just with a remap.

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Is that a common problem, tps off?If its set wrong I see what your're saying. All my riding buddies on Hondas & the one I had, never flamed out.3 had eds mapping,1vortex,&1Tokyo mods tuning.I haven't seen or heard of half the issues posted on this site, but my moto world is very small(san diego ca.)vs the world wide web.

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Tried a clean race fuel yet? Sorry if this was already mentioned but I did not see this in Mike's first post. I had this problem Mike is describing on my 11. Did all the mapping, added rekluse, turned up idle, etc..  I bumped to VP T4 and or Rebel 100 pump gas(local race fuel here at the pump in Vegas)  Solved all my issues.(with the stock spark plug) I spoke to VP and they recommended the T4 to help with Throttle response and that T4 is designed for stock or slightly moded 4t's. I went back to 91 at the pump at the Shell station to check it again, and started having the issue again. So I run nothing but 100 or VP. I run Desert and MX. Could be worth a shot Mike.

Edited by Killswitch202

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Is that a common problem, tps off?If its set wrong I see what your're saying. All my riding buddies on Hondas & the one I had, never flamed out.3 had eds mapping,1vortex,&1Tokyo mods tuning.I haven't seen or heard of half the issues posted on this site, but my moto world is very small(san diego ca.)vs the world wide web.

I think its more common than most will admit too. Suzuki had a recall on the first gen TL1000's because of it.

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Tried a clean race fuel yet? Sorry if this was already mentioned but I did not see this in Mike's first post. I had this problem Mike is describing on my 11. Did all the mapping, added rekluse, turned up idle, etc..  I bumped to VP T4 and or Rebel 100 pump gas(local race fuel here at the pump in Vegas)  Solved all my issues.(with the stock spark plug) I spoke to VP and they recommended the T4 to help with Throttle response and that T4 is designed for stock or slightly moded 4t's. I went back to 91 at the pump at the Shell station to check it again, and started having the issue again. So I run nothing but 100 or VP. I run Desert and MX. Could be worth a shot Mike.

Good point Killswitch.. a couple of others recommended that too, but I havent tried it yet as it is not so easy to get race fuel where I am in North Jersey. I have been using Sunoco 94 octane.  I think I am going to try the Injectioneering route and another remapping after talking to Wade and Tokyo Mods yesterday. If that doesnt do it.. I will find a way to get a 55 gallon drum of VP fuel. It is a problem that really ruins a decent bike.. I end up parking it and jumping on my CR250 2 stroke... I will lick this bugger.

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Is that a common problem, tps off?If its set wrong I see what your're saying. All my riding buddies on Hondas & the one I had, never flamed out.3 had eds mapping,1vortex,&1Tokyo mods tuning.I haven't seen or heard of half the issues posted on this site, but my moto world is very small(san diego ca.)vs the world wide web.

Same here with an 09 & 10 I didn't have any issues with flame outs after remaps even with the 50mm TB.   Eddie Sisneros has good maps for these bikes (did both bikes).  The 09 did it a couple of times with the stock map, but after the remap it ran very good from off idle into the higher rpms on CA 76 / 91octane pump gas.   

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