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CRF450R 07, hard to start after shimming valve clearance to .006

By thedon74,
in CRF450R/RS/RWE & RX

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thedon74

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Just reshimmed intake valves to .006 (actually Honda shop did it since I bound up the cam chain when i tried it) either way. Before shimming bike would start super easy left intake was almost zeroed out though and right side was at .005. Now with both at .006 its seems alot harder to start, really have to whale on it to get it to start and seems to hang up sometime and cant hardly kick it at all. I really dont know the best way to start these things, I never gave it any gas before, would set choke when cold and would normally kick over 1st or second kick, and when warm always started on first kick unless i had just dumped it or stalled it, never even had to use hot start lever before. The short of it, is this normal with redoing the shims and am I doing something else wrong I dont? I only asked cause mech at Honda started it right up when i was standing there?

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thedon74

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it is pretty hard to kick now, the whole reason I took it to honda in the first place is I had shimmed it, put it together and it was really haed to start and kick, so i though i had done something wrong or the timing was off. When i took it apart the second time is when the timing chain came off and I could not get it back on or unbound. the wreird thing is when i did get it stated and rode it, it felt like it had less power than the day before when i had ridden it with the left side intake almost zeroed out?

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JJRace

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well if you take it apart, show them the timing marks if they are mistimed, have them fix it. learning lesson for you and the mechanic.

Hondas are the easiest to time with the different triangles and hash marks. If use the right side balancer mark, SUPER easy to get 1 tooth off. You have to use the timing mark on the flywheel.

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xxxshiftxxx

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well sounds like i will be taking the valve cover off and checking the timing, I really hope it is off one tooth, this really takes all the fun out of riding if it is going to be a pain to start.

trust me, I feel your pain from when I had my CRF 450's.... Its a high performance machine that requires love... It is well worth the work, because riding it was a blast!! once you get the hang of it, you can check valves, timing in no time and its super easy... good luck and dont judge the bike from this one hicup. You will forget all about it when you get her running again..:bonk:

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Shawn_Mc

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well sounds like i will be taking the valve cover off and checking the timing, I really hope it is off one tooth, this really takes all the fun out of riding if it is going to be a pain to start.

They just missed the timing. Its easy to do.

If the shop is any good it shouldnt take more than about 15 minutes to fix it.

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wade234

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Now I am worried. I just ordered the Hot CAM Shim kit to do my valves. It is just starting to get hard to start and the starter has less resistance (I guess this is called compression?). I have watched all the videos and looked at as many write-ups as possible. I have never dug this far into any engine before but I have done other maintenance like clean carburetors. It does not look too hard. I am interested in how the timing chain came off. The one video I watch showed using a tie to hold it up out of the engine. Any other pointers I should watch for? Thanks.

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corndog

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Hi Don, the bi.ke is fine, you just need to learn the technique to start it. When the bi.ke is cold, twist the thr.ottle 2-4 times (2 in summer, 4 in winter), then slowly kick all the way through the stroke 3 times (slowly, not actually trying to start the bike), then its time to kick it for realsies. When you go to give it a real kick, slowly kick through the stroke until you get to the compression stroke, you'll know you're there when the kickstarter hits a spot where it's harder than the other little spots. Once you're there, you need to move the kickstarter just a pinch more, so you're just baaaarely past the hardest part, then bring the kickstarter all the way up and give it a solid kick all the way through the stroke. Remember that this is a cold start procedure assuming that you haven't been fkng with the thing for an hour, choke on and hand completely off the thro.ttle. Also note that this is just what works on my bike, everyone does it a little different.

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corndog

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Now I am worried. I just ordered the Hot CAM Shim kit to do my valves. It is just starting to get hard to start and the starter has less resistance (I guess this is called compression?). I have watched all the videos and looked at as many write-ups as possible. I have never dug this far into any engine before but I have done other maintenance like clean carburetors. It does not look too hard. I am interested in how the timing chain came off. The one video I watch showed using a tie to hold it up out of the engine. Any other pointers I should watch for? Thanks.

It's surprisingly easy, just take your time and stay organized. The timing chain comes off in a few easy steps. Remove the tensioner (or use the special tool or screwdriver/vice-grip trick), this will give the chain a little slack, but not enough to take it off the gear. Then you will need to remove the two all.an bo.lts that attach the cam gear to the camshaft (you'll need to rotate the engine a little to get to the opposing fastener, just make sure you put it back where it was at TDC). Once those two fasteners are removed, you can pull off the cam gear, but make sure you are holding the cam gear and chain because you don't want to drop them down the cam chain opening (not a huge deal if you do). Make sure you have some string handy when you remove the gear so you can tie it around the chain and another part of the bike to keep the chain from falling in. Then it's just four bo.lts to pull the whole cam assembly out, easy peasy. Crfsonly has a couple good links...

http://crfsonly.com/howto/450r/valve-check/450r-valve-check.php

http://crfsonly.com/calculators/crf450-valve-shim-calc.php

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Shawn_Mc

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Now I am worried. I just ordered the Hot CAM Shim kit to do my valves. It is just starting to get hard to start and the starter has less resistance (I guess this is called compression?). I have watched all the videos and looked at as many write-ups as possible. I have never dug this far into any engine before but I have done other maintenance like clean carburetors. It does not look too hard. I am interested in how the timing chain came off. The one video I watch showed using a tie to hold it up out of the engine. Any other pointers I should watch for? Thanks.

If the bike starts easy, its not worn out. Its worn out when it wont start.

You'd be doing yourself a disservice if you dove in and started adjusting valves that dont need adjusting.

Check the clearance first (Clearance is also known as lash). If the lash is ok, just leave it. If its out by .002". just leave it.

If its hard to start (takes several +5 kicks) to get running, then check them, then if they're tight adjust them. If they aren't tight...dont fix it cuz it aint broke and your issue is probably the carb and its probably just dirty.

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thedon74

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Not sure if it is right or not but I am able to start it. The shop did not care to hear anything about the timing marks on the flywheel, they set it off the mark on the right side of the mottor that requires 8mm allen to turn the motor over (primary gear I think). Either way. It is still harder to start than before I did the shimming, I have to find the compressoin stroke and then get it just past TDC then kick the crap out of it one good time. Not sure if i was just spoiled from being able to just kick it anywere once and it would start before I shimmed it or the Honda Guys at liberty are full of it. What do you guys think, should the timing marks on the flywheel match the cam gear or just leave it be?

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corndog

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Cheers Link, works about the same on mine too.

Don, mine was harder to kick after my left intake was shimmed correctly. Previously, it took ten+ kicks to start it cold and I could kick it like a 125. I'm not sure where it was at, but the .002 wouldn't go. I never touched the decompression lash since it was in spec, but it's way harder to kick now. I was a little confused by it, because I don't think there should have been a perceivable difference, but the bike is really happy right now and I'm just going to let it be happy! Also, the flywheel marks are for ignition timing, I wouldn't try to use them for cam timing.

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JJRace

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Not sure if it is right or not but I am able to start it. The shop did not care to hear anything about the timing marks on the flywheel, they set it off the mark on the right side of the mottor that requires 8mm allen to turn the motor over (primary gear I think). Either way. It is still harder to start than before I did the shimming, I have to find the compressoin stroke and then get it just past TDC then kick the crap out of it one good time. Not sure if i was just spoiled from being able to just kick it anywere once and it would start before I shimmed it or the Honda Guys at liberty are full of it. What do you guys think, should the timing marks on the flywheel match the cam gear or just leave it be?

That is not the ignition timing marks. That is the marks for the balancer gear, thus they are 1 tooth off causing the hard starting

I would either have them do it right or ask for a refund. If you have to hope you paid with a CC and debate the charge.

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