W85W58

2012 WR450 Starting woes

506 posts in this topic

Has anybody with the starting problems had their TPS checked? I am wondering if that could affect it. Sometimes I have to barely crack the throttle... then it starts fine.

Share this post


Link to post
Share on other sites

I'm in Colorado and have gone through all this crap as well. Took to the dealer and they adjusted the idle speed upward and changed the oil to a much lighter weight. It is starting finally and I'm using stock ECU etc. I have the GYTR and computer, not sure why I bought them now. Anyhow, I've only got 80 miles on this bike but its starting to be the bike I thought I bought.

Share this post


Link to post
Share on other sites

I have the GYTR and computer, not sure why I bought them now.

Install the GYT-R Comp ECU and you will soon see why you bought them.

Share this post


Link to post
Share on other sites

You have to listen to the fuel pump prime. My procedure is to push button, prime fuel pump, when it stops I hit the starter briefly 3-4cycles, stop, let the fuel pump prime again, hit starter again for 3-4 cycles. I always start it cold in nuetral, hot either or. Never had a problem, starts 50% of the time on first crank and 50% on second crank.

Share this post


Link to post
Share on other sites

I had a huge problem with starts while the engine was warm/hot for a while. It killed me at all of my dead engine start desert races.

I have since learned that putting the bike in neutral does the trick. Less load = easier starting?

Now I pull hole shots for my line on the regular. This bike is a monster and so much traction!

Share this post


Link to post
Share on other sites

Hey guys, I have had similar starting problems that most of you have had here in this post. I have over 1000 miles on my '12 and it hasn't gotten any better. In fact lately it seems to be worse. I've tried all the tricks posted here, the cracking of the throttle, waiting for the pump, etc., and all of it worked some time but not always. Well this weekend I finally found what my bike likes and it works 100% of the time whether I stall it, shut off normally, in gear or not. I found that if I hold the throttle wide open and crank it for 1/2 a second, release the throttle and hit the starter a second time it fires every time. I'm assuming a big gulp of air clears out the cylinder for a clean start. By the way my bike starts first push of the button when cold every time so if your bike is similar this might work for you. I realize some bikes might be hard starting because they are rich or lean. I figured mine was rich when it stopped. I would rather have a bike that always starts on the first try but I will accept two tries.

2 people like this

Share this post


Link to post
Share on other sites

My WR runs the stop screw out, plug out of the pipe, comp ECU, and the woods map. It starts first push 90% of the time cold and and 50% of the time warm. Ive found that the other 50% of the time, that timing with just a quick push of the start button is the key. Just enough the get it past 1 one stroke, just like a kick would do. If I hold down the button it won't start. Its like the starter puts to much drag on stroke to let the compression carry it into the next stroke. Lets not forget these WR's have auto decompression during starting. I found this way of starting from starting large RC helicopters. Where just a quick bump of the stater is what it took to get them started. If it won't start, I put it in neutral open it up and give the starter a few turns.Then I let off throttle and give the starter a quick bump and it starts.

Hope this helps some.

Edited by vlxjim
1 person likes this

Share this post


Link to post
Share on other sites

Has anyone tried checking and or adjusting the tps. I noticed mine reads 0 with no input at the twist throttle. After looking through the service manual, it states that the tps should read 8-16? with no throttle input. At least that,s my interpretation of it.

My tps reads well below 100 at wide open with the throttle stop screw cut off very short. Does that seem normal?

Share this post


Link to post
Share on other sites

Hey guys make sure your idle isn't set too low. My bike was a bitch to start hot, no dice in gear and tough even in neutral (starts fine cold). I have a Magura juice clutch and it had too much free play and so I thought it may have been dragging a bit, so I got that sorted out but it still wasn't starting when hot.

Then yesterday while riding I remembered someone posted here saying they used the 'choke' and it helped, so I tried it and it worked. Then I went and turned my idle up a bit, and voila! Starts hot now, even in gear! The only time it seems to be hard starting now is if it's really hot, like after going through some super slow tight stuff, like 1st gear and working the clutch constantly type thing. Hopefully this helps some of you.

Share this post


Link to post
Share on other sites

Follow up on my last post... I checked my owner's manual and it says the idle should be 1900-2100 RPM minimum. If you have the GYTR tuner you can check this yourself in monitor mode. Mine was at about 2200 RPM *after* I turned it up on my ride, so I was definitely too low before, which was contributing to the hot start issue that is now mostly gone.

Share this post


Link to post
Share on other sites

Thanks for this thread. I don't know if my dealer was smart enough to figure this problem out on their own but once I told them what people said was the potential fix they looked it up, hooked up the computer to the connector near the ECU (it's a little black box about 2 inches by 4 inches...not the power tuner) and stuck some probe up the exhaust pipe and started pushing buttons until the CO (Carbon Monoxide) reading hit about 4 I think. It took them about 5 minutes to fix it. They said it took longer to get the equipment out than to fix the problem and didn't even charge me!

One more note. They said if I changed out the ECU for a competition ECU, or de-restricted it by removing the air filter thing or the exhaust pipe tip then I might need to bring it back to have it re-tuned. Oh yes...and they would charge me next time but said it would be the minimum shop time charge.

Share this post


Link to post
Share on other sites

let me comment now that i have put about 75 miles on my 2013 wr

i have noticed just like in this thread others have stated it is hard to start. i agree if you give it too much throttle, or none at all it will not start. in fact it wont start if you keep cranking and try to find the sweet spot just off idle that it will normally start with.

but i can start my bike with 100% reliability if you just crack the throttle open a tad before you hit the button. if you do anything different from this it will not start and you wont get it to start without some effort.

i have found that if it doesn't light on the first or second attempt and you gave it too much throttle try opening the throttle all the way, spin the engine a few times, then just crack it open slightly and it will fire right up.

the key seems to be just cracking it open, likes someone described, enough that it puts tension on the throttle cable. a few times it started with no throttle input at all, but just cracking it gets it to light off every time. the owners manuel even mentions this if you read it.

anyway, thats my observations and i couldn't be happier with this bike.

1 person likes this

Share this post


Link to post
Share on other sites

Whilst i am still running mine in, increasing the idle speed to 2200rpm has helped and has not adverse effects on performance. The other key thing is letting the fuel pump prime before expecting it to start. I usually give 3 cranks if it hasn't fired, let off fuel pump prime and hit it again and it will fire every time. Also just taking the free play out of the throttle slightly acting on the tb helps for hot start.

&%$#@!ing great bike with a few little quirks,

Share this post


Link to post
Share on other sites

Had my valves adjusted, one of my intakes was out. The bike probably has close to eighty hours on it now (no tuner). I didn't notice it until the bike would not start at all. Now, it starts with the button in gear and hot, and it never would before. I didn't even need to use the hot start. I rode for about three hours last night and not once did I need to kick it. Man I love this bike.

Share this post


Link to post
Share on other sites

Ah...the way you said it before, it sounded like you were pulling the old style plunger out of the carb via the lever mounted cable or plunger on the side of the carb....which of course, there is none.

Share this post


Link to post
Share on other sites

Ah...the way you said it before, it sounded like you were pulling the old style plunger out of the carb via the lever mounted cable or plunger on the side of the carb....which of course, there is none.

Its not a carb its a throttle body. And there is a knob (plunger) you pull on it for cold start. Also you turn it for idle speed adjustments as well. I don't use the cold start knob, well not yet here in SoCal its warm. It does help the bike warmup quicker. There is two lines on the housing next to the grip flange. In hot start you just move between the lines. If you do it this way it is good to put a mark on the grip next to the housing mark.

Share this post


Link to post
Share on other sites

Its not a carb its a throttle body. And there is a knob (plunger) you pull on it for cold start. Also you turn it for idle speed adjustments as well. I don't use the cold start knob, well not yet here in SoCal its warm. It does help the bike warmup quicker. There is two lines on the housing next to the grip flange. In hot start you just move between the lines. If you do it this way it is good to put a mark on the grip next to the housing mark.

Thanks, I'm aware of the FI on the 2012....I have one. When CW Shasta mentioned hot start I thought he was refering to the carb....not FI.

Share this post


Link to post
Share on other sites

Finally decided to get my idle mixture checked after a painful weekend of hard starting.  Called my dealer and he had no idea.  Said they only had the GYTR hand tuner, the same as mine.  Can anyone tell me exactly what their dealer used to adjust the idle mixture?  Thanks.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


  • Similar Content

    • By RidingTheFort
      So I want to share a solution I discovered today for what seems to be a somewhat common issue. 
      First a little background, I ride a 2007 YZ144 set up for the woods and I had recently started to develop some slack in the rear end, so I had a buddy help me look and sure enough it was moving in the linkage. So I just received my new bearings and went to press out all the old bearings today. Using all-thread, some thick washers, and some nuts I was able to press out all the bearings in the linkage reasonably quickly (once I figured out to use a smaller socket so I wasn't hitting the shoulder). 
      But then I ran into a dead-end.. the connecting link, dog bone, wish bone etc. has a shoulder, or raised sleeve, between the two bearings preventing you from pushing them both out one side. Now from my understanding this isn't the case on every bike, some bikes don't have a shoulder and the bearings in the connecting link can both be pressed out one side but my service manual clearly showed a shoulder. After some searching nobody really had a great method for removing these bearings except for buying a blind bearing puller. So I bought a cheap blind bearing puller from Harbor Freight but this did not work for me, it was slightly too large. So back to the drawing board.. then I discovered this video: https://www.youtube.com/watch?v=4YRA3nhzXX0
      Essentially, these races can be hammered out from the opposite side using a concrete expansion anchor that cost $2.69 at my local Ace Hardware Store. The one I found and used was slightly different from the one shown in the above video but there are many different styles that would probably work. Mine was luckily just the right length where I didn't need to use all thread or anything. Just slide it through to the race on the opposite side and expand it once inside (remove the needles before hand by the way). Once I had it in there and expanded, a few solid hammer blows (with wood underneath) and it came right out.  See below for pictures of how it works. 
      I've seen the question asked on these forums several times with no solution other than "buy a blind bearing puller" so hopefully this helps some people out. 
       
       






    • By jimDavis
      I live in Iquitos, Peru where motorcycles and moto taxis (tuk tuks) are the primary form of transportation.  We live a ways out of town 3 KM up a pretty rough dirt road.  After riding a Honda CRF250L dual sport several years to get to town and occasionally riding trails I bought our son a CRF230F.  After riding that on some trails I decided its time to get back into dirt biking. It was so much more fun than the CRF250L dual sport.  I wanted a bigger bike as the frame on the 230 is pretty small and it does not have much power.  I really wanted a WR250F, but, unfortunately, they are not sold in Peru.  I definitely did not want a motocross bike, we only have Yamaha and Honda dealers where I live, so the WR450F was pretty much the only reasonable option.  The weight concerned me as I am 57 years old and not in the best of condition, and I was also concerned it would have way more power than I could control.  I rode a Huqvarna 125 when I was 16-20 and it was a blast.  Very easy to flick around.  After lots of reading I decided I could learn throttle control and only use what I needed.
      So I got a new 2015 WR450F and could barely ride the thing!  The problem was the compression braking.  Any decrease of throttle felt like I was going to go over the handle bars!  Any small change of throttle seemed to have an extreme effect.  I did start adapting to it, but it was very difficult to control at low speeds on tight or rugged trails.  After some research,  I bought a G2 Throttle Cam System and that made a HUGE difference in controlling the engine response. Finally, I was able to actually enjoy riding it!  With the G2 Cam System I began riding a bit more aggressively and very quickly realized that while I was a fairly good trail rider when I was 18, the body does not remember things that well after 40 years.  My technique sucked and with the weight of the bike and my so so conditioning I got worn out very quickly.  I have to say I did find myself regretting my decision a bit, wishing I had something lighter.
      I started looking up articles about how to ride a dirt bike, how to turn, ride woops, where to put your feet, how to position your body, etc.  While wishing I had a lighter bike, I also knew there just were not any real options where I live except a Yamaha or Honda 250F motocross bike and I did not want the gear ratio, power band, or suspension of one of those as most of my riding is on trails.  What I decided to do was focus on my technique and learn to let the bike do most of the work.  Where before I would try to go fast (for me) on trails, I backed it off about 30% and just focused on form and technique.  Body position, throttle control, standing on the balls of my feet with my toes turned in so my legs naturally gripped the bike.  I focused on being smooth, on flowing down trails and over bumps, accelerating smoothly out of turns and learning to keep the rear wheel hooked up and not sliding out.  Initially it was kind of boring but I kind of made a game out of it. How can I get down this trail at reasonable velocity while using the minimum amount of energy and let the bike do most of the work?  What I found after a couple of weeks of this is I was riding much faster than before, had much more control and did not get anywhere near as tired.  I was also having a lot more fun!  This is an incredibly stable machine and will easily soak up any kind of terrain I point it at.  I am still trying to figure out how to consistently get over the bikes tendency to stand up in corners.
      All of this learning was on the stock, bottled up WR.  I was definitely disappointed with the power once I got used to riding it, but was content for a while.  I wanted to take out the throttle screw, but you cannot buy a Torx 25 security bit here, so I just rode it as is for a while.  I just got around to buying the competition kit and put in the ECU today without making any other changes – stock exhaust and stock air intake, restricted throttle.  My first ride with the default competition ECU settings.  WOW!! What a difference!  It is so much easier to pull the front end up and has more power and acceleration throughout the RPM range.  Honestly, I think I would like riding it with those default settings.  I did buy the power tuner and wanted to see what effect it really had.  I loaded the muddy/slippery surface map and took it out for a spin.  Seemed like a different motorcycle.  Much better traction, but with a very bottled up feeling that was worse than the original ECU, but it did have a hard hit in the mid-range.  I did not like riding with that map but can see how it would be useful in very slippery, tricky trails.
      I next loaded a motocross map that was intended for use with a YZ exhaust, the other extreme as I was looking to see what kind of difference the power tuner can make. Good God Almighty!!  This bike is F@#K3ng FAST.  I could not believe this was the same motorcycle.  Without any other changes, just the competition ECU, this WR450F has more power than I will every really need.  I will be taking it to the shop soon for a variety of maintenance and I will have them change the throttle screw.  I am looking forward to see if that will give me a bit more power while at lower RPMs.  It definitely has all I need in the mid to top end.
      I still think I would have been happier if I could have gotten a WR250F.  From all I have read they have plenty of power, and I am only 160lbs.  I do like my WR450F and have a lot of fun riding it, but there definitely  are times where the weight is a factor.  As long as my form is good it is not too much of an issue, but if I get off balance in a tricky slow section I really notice it.  It also limits my confidence learning to jump things as I find it very difficult to change its attitude in the air.  Do bear in mind I am 57 and not in the best of shape and finally accepting I will never ride a dirt bike like I did when I was 18.  I really do not want to get hurt again (hit a tree, broke a collar bone and damaged my rotator cuff and did not get to ride for 6 months) as healing takes a long time at this age, so I do not push it too hard.  One thing I do expect from this machine is a long life.  I will hardly every be using all the power of the engine, mostly staying in the mid rpm range, so I hope the engine will last a long time with just the standard regular maintenance.  My plan is to happily be riding this bike when I am 65!!  Maybe by then there will be better options in Peru and the wife will let me get one.  Dirt bikes are a great way to stay in shape and I see no reason can’t keep riding into my 70s.
      We will be getting our son a YZ250F soon as he does ride motocross tracks on his CRF230.  I will get to ride that and see if I made the right choice not going for a motocross bike.  I will probably keep the stock exhaust as I do like having a quiet bike and I have no need for more power.  It is also very expensive to ship things to Peru, so I really can’t justify the expense of the FMF Q4 (over $600 by the time I paid shipping and customs) , though I would like to have it just because it sounds so much better
       
       
       
       
       
       
    • By EDL96
      Just bought a new 2017 yz250fx, has about 2 hours on it and ive already done an oil change, and overall made sure everything is in good condition.
      I rode for about an hour last Saturday around a farm and than stopped to turn off the bike, about 20 minutes later I came back and started it up and now every time I rev it/ blip the throttle the bike just shuts off.
      Than about 6 days later tried again, Now it wont even run without choke, I warm the bike up on choke and as soon as I shut it off bike turns off
      Not only do I want to fix this so i can ride my NEW bike, I am very pissed because its brand new and ive done nothing wrong to it.
      Any help is much appreciated 
    • By nate9521
      So apparently some mx fcr carbs have removable valve seats and some dont. I didnt know this and just thought mine was really stuck in there so i drilled it out. Was going to replace it anyway. But it turns out that i have the model that is not suppose to have the valve seat removed. or so i think. Is anyone aware of this difference between the same carb. Do you know where i can get another valve seat? its off a 2003 yz450f
    • By Hammerthrottle
      Hey all, recently getting into motocross again and bought a used bike from a kid who lacked on the maintenance side of things for the bike. What I have found / believe is happening is oil is leaking out of the cylinder head breather tube. Before going on my first ride with the bike I had a respectable amount of oil right in the middle of the checkered oil marks on the dip sticks. However after about 5 hours riding I checked the oil to find that it was barely even on the dip stick. I know there has been oil leaking out of the breather but could have been caused because an overflow on the oil change from the kid. I mean the bike is 8 years old maybe it is time for some top end work. On that note would a person change out the piston regardless of condition along with the rings? Is it possible the rings are just not positioned right? I would definitely do the valves while I have the bike open anyways.
       
      Any info would be greatly appreciated I just find it odd that it took 5 hours to drain, reading through other posts some guys were having puddles of oil after 20 minuets of running time.