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Hard Start After Oil Change

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Everytime after I change my oil, my bike won't start. I'm using the bleeder screw like the manual says. I usually have to change the plug and then kick it until I'm real good and sweaty. The old plug is pretty black when I take it out. After I get it started that first time ( after the oil change ) it willl start the first or second kick almost everytime...it runs excellently. Does anyone know what the problem could be cause its very frustrating and makes me not want to change my oil.

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If you are starting the bike to get it warm before changing the oil, then shutting the engine down before warming it up completely (I know, sounds strange) then you can foul your plug. I've never had a problem with mine, but there have been guys that have had issues. One habit I always do when I shut it off at any time is rev the motor up with a throttle blip then hit the kill switch just after I twist the throttle back to idle. Whether this has helped me not foul plugs after a short running of the motor or not is beyond me....but I have never had issues like you are describing. Try getting the motor warm by riding it for 5-10 minutes.

Changing the oil alone should have no effect on how it starts.

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Its an 04 450. It is stock except for the full T-i4 pro-circuit exhaust. Sorry I didn't mention that to begin with.

I have an 04' 450 as well, right now mine will not start either. I think I may have fouled a plug after I warmed it up last. It is very cold here in Idaho at the moment- I wonder if the jetting could be so far off that it will not start (because of the temp)? I am going to pull the plug and replace it with a new one and see if it will come to life.

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I've only had the bike long enough for 3 oil changes and I've had to put a plug in it 2 of those times. My point is, is that I should not have to do that. The plug should very rarely foul on that bike.

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I've only had the bike long enough for 3 oil changes and I've had to put a plug in it 2 of those times. My point is, is that I should not have to do that. The plug should very rarely foul on that bike.

Tell us your jetting setup. You bought it used.

My 03 does not have this problem. Maybe your jetting is too rich or off in some way.

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As far as I know it's stock. I guess it should be adjusted because of the pipe. Do you know where it should be??

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As far as I know it's stock. I guess it should be adjusted because of the pipe. Do you know where it should be?? I've never bothered to change it since it always runs so good.

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As far as I know it's stock. I guess it should be adjusted because of the pipe. Do you know where it should be??

http://www.thumpertalk.com/forum/showthread.php?t=248849

You can get real close if you look at the JETTING thread right above this one.

You'll need to know where you're at though so looks like you are going to spend some time getting to know your carby. :applause:

I've noticed some people jet thier bikes overly rich for some reason, but you need to tell us what all is in there. Be sure and go get you a manual for your bike. It's very helpful.

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A fresh plug will probably solve the problem for you.

Yep, you were right grayracer the new plug fired her right up. :applause: That was the first plug I have fouled. I have changed plugs in the past but never because they were fouled. I must have wet the plug last time I warmed her up. It is too damn cold here in Idaho to ride, so I periodically start my bike up in the garage.

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have an 05 wr and Ive never had anything like this happen but then my bike is soooo lean!!!! black plug says rich to me ????

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Mine never starts after oil change either but that is because I also clean the air filter with soap and water before putting on the filter oil..

I figure it is the residual water on the air filter that is the problem, because when i let it dry out for a couple of hours it starts right up fine..

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Are you just starting it up for a few minutes to warm it up for the change or riding it around for 5-10 minutes?

It sounds to me like you just aren't getting it hot enough. I've had that problem before too. These bikes don't like to be started for a minute or two then shut off. Well more precisely, the plug doesn't like it.

My advice is to ride it around for a bit instead of just starting it in the driveway for a minute or two.

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1) It's not the oil change; it's something you're doing with the oil change. Such as starting the bike but not letting it get all the way hot, as mentioned above

2) On a 4-stroke it's sometimes difficult to tell the difference between rich and lean. Both overly rich and overly lean can leave you with puffs of black smoke and black spark plugs.

3) Make sure you're not twisting the throttle while you're moving the bike around.

The plug is probably still good, just covered with gas+oil. Get some carb cleaner and goggles and spray it good, epecially down around the electrode. Blow it if, put it back in and I'll bet it fires right up.

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ok, thanks guys...I'll try and let it warm up for a while before I change the oil. I was just doing it when the bike was cold.

I also clean the filter when I change the oil...maybe that does have something to do with it. Thanks again

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No need to let it warm up really; we thought you were starting it and only letting it run for a minute or two, then turning it off.

The air filter could definitely have something to do with it. Be sure you completely dry the filter before you oil it, and then let the oil set up for at least a few minutes before you start it. You may want to let it set up for several hours before a ride if it's the aerosol oil; that stuff takes a wile to completely tack and can get sucked into the carb if it's still sloppy when you ride.

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ok, thanks guys...I'll try and let it warm up for a while before I change the oil. I was just doing it when the bike was cold.

I also clean the filter when I change the oil...maybe that does have something to do with it. Thanks again

Air filter for sure!

Way back in the '99 test of the YZ400F, the mag said that if you clean you filter then oil it up real good, it won't start. (I figure this is true for the newer YZ's too) I thought that was bull . . . until it happened to me! I oiled it up with UNI foam filter oil, squeezed out the excess, installed it. Took forever to start. After it did start, took 3 or 4 laps on MX track to run decently at all. Next weekend I rode again; hard starting, wouldn't run as well, backfired, etc. THEN I swapped filter with old one (still not too dirty, and oiled, but not as saturated). VIOLA! Easy starting, better running, less backfiring.

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