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Bike being very finicky, pictures.

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Hi guys. I am having problems with my 06 450r.

it will start fine when its cold, or cooled down, but once you ride it it doesnt want to kickstart but will bump fine. heres some pictures and my specs, hopefully someone can help me as im supposed to ride tomorrow!

heres my timing marks, im positive the timing is correct:

35jwkys.jpg

24aztae.jpg

this is the 2nd flywheel mark:

2ez3bra.jpg

heres my specs:

intakes are .15mm, where they should be.

exhausts are a little fat.. approx .30mm

the decomp clearance is proper, .25mm I believe (its .011 thou for sure, not sure what that translates into mm)

heres what I think/hope the problem is, simple as a spark plug.. looks to be running very lean. can I fix this by 1. jetting bigger? or 2. openining up the fuel screw a little bit?

jiccit.jpg

otherwise I have NO idea why the bike wont kickstart at times, but it bomb starts just fine down a hill or being towed for 10 feet. intakes are fine, decomp arm clearance is fine, new piston so im sure compression is fine, new gas... what do I check next?

thank you :worship:

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what do you mean it doesnt want to kick start? like the kickstaarter wont go down, or it just doesnt start? if it just doesnt start its a four stroke thing.. they do that. maybe your valves need to be checked? if your kick starter doesnt go downt then theres trouble, something in the gearing, vibration moved something? heat deformed something. could be anything... best of luck!

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Do a leak down test. Not to be confused with a compression test. You say it has proper intake valve clearance but your symptoms indicate bad intake/s. Jetting is probably not the problem if it ran properly before.

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what do you mean it doesnt want to kick start? like the kickstaarter wont go down, or it just doesnt start? if it just doesnt start its a four stroke thing.. they do that. maybe your valves need to be checked? if your kick starter doesnt go downt then theres trouble, something in the gearing, vibration moved something? heat deformed something. could be anything... best of luck!

well its kinda a little of both. if I try to kick it down non stop and real fast sometimes the kickstart kinda locks up on me, or feels like it does... maybe it just gets super super tight and I dont have enough weight, or my foot slips off. otherwise its normally fine. it will kickstart sometimes and the bike will fire first kick... sometimes it takes 50 kicks and I have to let it sit for 10 mins then it finally decides to start.

valves dont need to be checked, its a fairly new head and I just checked them, all in spec like I mentioned earlier.

thanks

It's rich!What pilot jet is in it?mixture seting?

rich you say? how come its so white around the electrode then? im not 100% sure whats currently in it, whatever the JD jet kit told me to put in it :ride: it ran fine last summer, and I just rebuilt the engine and am now having minor problems.

it doesnt want to kickstart sometimes, but a jump start works just fine. I cant figure it out!!! :thumbsup:

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Do a leak down test. Not to be confused with a compression test. You say it has proper intake valve clearance but your symptoms indicate bad intake/s. Jetting is probably not the problem if it ran properly before.

ok.. how do I do a leak down test, and what does that test for?

its a brand new engine except for the crank. I replaced the head, cylinder, and piston about a month ago and only have 4-5 hours on the bike since.

sometimes it starts first kick.. sometimes it takes 50. why?

thanks for the advice.

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Have you checked the intake valve clearance lately? It may have closed up since your rebuild.

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Have you checked the intake valve clearance lately? It may have closed up since your rebuild.

lol youre the 2nd person to ask that.. I posted the specs in between the pictures so that must be why youre missing it all; it got buried between the pictures.

yes, I just checked the intakes, theyre spot on at .15mm

the exhausts are .30mm

the decompressor is .35mm which I think might be the problem. my manual says to set it at .35mm but I googled my problem and someone said I should have my decompressor as .35 + exhaust clearance, so .35 + .30 = .65mm decompressor clearance?

thank you.

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also, another thing that makes me think its the decompressor is sometimes when im kicking it, the kickstart seems to lock up on me. maybe it doesnt exactly lock up, but it gets very very very stiff to the point where it makes my foot slide off the kickstart and it feels like it locked up, but really just got super super stiff.

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sounds like ur twisting the throttle when kicking...dont. and ur spark plug isnt suppose to be white at the tip and then black the rest, a properly tuned carb is suppose to be a brownish color...i would tweak with the jetting like the other guy said.

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I went thru some problems and it was the decomp lever. It should be set at .011 or .28 mm. If its "locking up", it probably means your decomp lever is not releasing properly, just that little bit out of tolerance cause cause it. Also, the improper set decomp lever was the reason it took my bike 50 kicks, it starts right up now. Good luck.

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also, another thing that makes me think its the decompressor is sometimes when im kicking it, the kickstart seems to lock up on me. maybe it doesnt exactly lock up, but it gets very very very stiff to the point where it makes my foot slide off the kickstart and it feels like it locked up, but really just got super super stiff.

That's definitely not right.

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I went thru some problems and it was the decomp lever. It should be set at .011 or .28 mm. If its "locking up", it probably means your decomp lever is not releasing properly, just that little bit out of tolerance cause cause it. Also, the improper set decomp lever was the reason it took my bike 50 kicks, it starts right up now. Good luck.

but my decompression lever is already set at .28mm and its still not being very cooperative :thumbsup:

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ive been researching on it for about 45 mins now and this is what I found.

"I did some mods to my carb at the first of this year, and adjusted the fuel screw a bit richer than I'd had it in the past. The bike started really easy when cold. But when it got hot it was nearly impossible to kick. On my first ride of the year at Moab it was so bad that I made a point not to kill the bike anywhere except on the top of a hill so I could let gravity start the bike for me. First thing I did when I got home was to order a quick adjust fuel screw. I leaned the fuel screw by turning it in by half a turn, and the bike has started very easily when hot ever since. On a subsequent ride, I decided to richen up the screw again (i.e., this seems to help keep the bike from stalling when going from full throttle to no throttle). Like clockwork, it became very hard to start when hot. With the quick adjust fuel screw, I closed it half a turn on the spot. All hot starts after this were very easy. So you might want to try closing down your fuel screw by 1/4 or 1/2 turn"

^^so that guy is saying to lean the fuel screw in about 1/4 turn or so.. but arent I already running a bit lean due to my white spark plug? jetting is my weak point, between the air screw, fuel screw, and jets its soooo confusing for me!

and that I should make my decompression gap BIGGER than .35mm (the manual says .35.. not .28 like I said in my last post), and that will make it easier to start?

any opinions guys? thanks.

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got it figured out guys. It was my decompression after all... I think the gap in it was too big, so it wasnt actually decompressing, thats why my kickstart would lock up sometimes, hopefully I didnt do any damage by doing that.

it just started first kick, every time, for 5 times, with 5 mins in between each try, im stoked now!!!!!!:ride::D:D:D:D:D:DD:D:D:D:D:D:D:D:D

I think the decomp gap was just a cnt hair too big, so I dont see why that one guy said to make the decomp gap .65mm... it definitely wouldnt be engaging at that point, UNLESS, he was assuming the gap in between your exhaust valve was .00mm, then it kinda makes sense.

I believe my decomp gap is now a tight .35mm ,maybe closer to .30 or .33. I rolled it over by hand very slowly and watched when the decomp pin rolled over, the decomp arm activated and opened the exhaust up a tiny tiny bit. success!!!

I also opened my fuel screw a half turn hoping it wont make my sparkplug as white/lean anymore! I also installed a new spark plug just for the hell of it... theyre only 30$ each :thumbsup:

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Great! But where did you get .35? I have an 06 crf450r and the manual clearly states .011 or .28. Other posts on different years were the same.

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Great! But where did you get .35? I have an 06 crf450r and the manual clearly states .011 or .28. Other posts on different years were the same.

1. I googled it and came across this info on allthingsmoto.com

Decompressor clearence:

Right exhaust valve clearence +0.35mm (0.014 in)

ex)

if measured right exhaust valve clearence is 0.28mm (0.011 in) ,decompressor clearence is;

0.28mm (0.011 in) + 0.35mm (0.014 in)=0.63mm (0.025 in)

2. my clymer manual which im really starting to not like :ride:

2h4ezc9.jpg

2dlkp5j.jpg

3. also, if I remember correctly, last time I did a rebuild my friend said his manual also says to use .35! w.t.f?

I dont care what all that stuff says, im going to start using .28 from now on. I crossed out all the .35s in my clymer manual and wrote .28 beside them for future reference :thumbsup:

ps: I wish I would have read/found this earlier... I really gotta start using the index in my manual more often!! I sure hope my valves aernt damaged.. my exhausts seem to be a tad loose, I could put the .33mm feeler gauge in there :lol:

2rw0xo5.jpg

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There are two ways to do this. After the valve clearances have been adjusted: 1) Using two separate feeler gauges, a .011” and a .014”, insert the .011” feeler gauge in between the rocker arm and the shim on the right side exhaust valve. Leave the feeler gauge in this position while using the .014” feeler gauge to adjust the decompression arm gap. 2) After you have set your exhaust valve clearance to .011”, remove the feeler gauge. Rest the rocker arm on the shim. Now use a .025” feeler gauge to set the gap between the rocker arm and decompression arm.

In some cases the decompression arm may need to be adjusted to compensate for variances in manufacture tolerances and/or engine wear. If the engine turns over too easily and backfires, the decompression clearance may need to be opened up slightly. If the engine turns over hard, the clearance may need to be closed up slightly.

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Hate to say it but it is probabley your crank going out. Had a half a dozon just like those symptoms . Had to replace

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