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stokebloke

is it possible?????

5 posts in this topic

hi

i am in the final stages of a wr 400 engine rebuild after the big end siezed!!!

is it possible that the cog/sprocket on the inlet cam could have moved???

i am having real difficulties getting the timing right.

i am lining the timing marks up on the flywheel with the mark, the exhaust cam lines up fine but if i put the inlet cam on the proper marks(i.e 9,12 and 3)and turn the engine over slowly by hand the engine locks at just over tdc on inspection it looks like the inlet cam is way out of wack and is opening the valves to quick????it is like it needs to be ither retarded or advanced 3/4 teeth

if i take both cams out and then turn the engine over it all runs smooth

any body ever experienced this????

needing your help with this one please

thanks

wayne

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hi

i am in the final stages of a wr 400 engine rebuild after the big end siezed!!!

is it possible that the cog/sprocket on the inlet cam could have moved???

i am having real difficulties getting the timing right.

i am lining the timing marks up on the flywheel with the mark, the exhaust cam lines up fine but if i put the inlet cam on the proper marks(i.e 9,12 and 3)and turn the engine over slowly by hand the engine locks at just over tdc on inspection it looks like the inlet cam is way out of wack and is opening the valves to quick????it is like it needs to be ither retarded or advanced 3/4 teeth

if i take both cams out and then turn the engine over it all runs smooth

any body ever experienced this????

needing your help with this one please

thanks

wayne

I'll start with the simple stuff first to get it out of the way - You have the flywheel set to TDC, correct? When you line up the marks on the cams, the lobes of both cams are pointing away from the valve buckets and the marks on the cam sprockets are level with the valve cover mating surface?

I had a degreeable cam sprocket turn on me after a seize, so I imagine it is possible for a stock pressed on unit to turn, but that's a bit unlikely, so let's go over the more likely stuff first.

It's been awhile since I've worked with stock cams but I think they had Int and EX stamped on the sprockets. Do yours line up like this?

camtining1.jpg

Even though these are aftermarket cams, the basic timing is still the same - engine set to TDC and the marks on the sprockets level - while the lobes are pointing away from the valve buckets. Just thought of something - did you properly install the small key between the flywheel and crankshaft. This properly locates the flywheel. if it's not there, then the TDC mark on your flywheel means nothing. Stick a straw ( or something similiar that won't damage anything) inside your sparkplug hole and check to see if TDC on the flywheel is actually when the piston is at the top of it's travel.

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thanks for the excellent reply frostbite that really helped me out with my situation.looks like the cam srocket had moved had the sprocket removed and pressed back on all back together now and just done about a hour of riding everything seems fine.

are those the hotcams that are in your photo as i have a chance of a set of second hand ones....are they any good on the 400 is there much of a performance gain to be had????

thanks again for the reply

wayne

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are those the hotcams that are in your photo as i have a chance of a set of second hand ones....are they any good on the 400 is there much of a performance gain to be had????

thanks again for the reply

wayne

I've been running hotcams (intake and exhaust ) for a few years in my 99 WR400. There's not any significant performance gain in my opinion, but the auto compression release exhaust cam is a nice improvement over stock.

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thanks for the excellent reply frostbite that really helped me out with my situation.looks like the cam srocket had moved had the sprocket removed and pressed back on all back together now and just done about a hour of riding everything seems fine.

are those the hotcams that are in your photo as i have a chance of a set of second hand ones....are they any good on the 400 is there much of a performance gain to be had????

thanks again for the reply

wayne

It's hard to say. I installed the cams, 430 kit and header at the same time so it's hard to say what did what, but the engine did work considerably better. My exhaust cam doesn't have the auto decomp.

My hotams were quite a bit out of spec when I checked them with a degree wheel , so I'd advise you to check them if you do buy. Glad to hear you got the stockers straightened out.:busted:

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