have a 1915 with stock heads, new valves, solid rocker shaft, 1.25 ratio rockers with swivel feet, 110 engle cam. motor was just rebuilt in april, broke it in with valvoline with zinc additive, brought the rpms up 2 2000 for 20 minutes. been on 3 "real" rides but mostly round the house and so one..
the problem is my valves keep vaking off. i have adjusted them over 10 times since i broke it in. the exhuast valves seem 2 loosen up the worst. sometimes as much as 1/4 in. it might take a couple days of hard riding or just a few minutes around the yard but they keep coming loose.if it is the cam wouldnt 1 and 3 back off the same amount and 2 and 4 be the same? it seems that 3 and 4 r usually worse than 1 and 2. #4 exhaust is usually worse than any. any 1 got any idea what might b goin on

looks like if you set them and locked them down theres no way they could back off,but the screw is backing out of the jam nut? might be the swivel feet doing it,as it lashes across the top of the valve stem it is turning and then its turning out the set screw maybe just a thought.chad

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well i had stock rockers and stock screws on it but it was doin the same thing then. it dont seem 2 be the screws and jam nuts. but then again it dont seem 2 b the cam 2 me either.ive adjusted them so much it looks 2 me like if it was the cam it wouldnt be enough left on the lobes 2 run good when they r adjusted. but i dont know i could b wrong. i just cant figure it out. when they r adjusted it runs great!!! it seems 2 me it would b runin bad all the time if it was the cam or lifters or am i wrong

make sure you adjust them when the engine is cold let it set over night and try if that dose not work check your monting studs nuts and the shims

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drive it like you know how too fix it

Make sure the flat part of the swivel feet is against the valve when adjusting them, I had one move on me before.

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"YOU CAN MAKE THINGS HAPPEN, WATCH THINGS HAPPEN OR WONDER WHAT THE F$$K HAPPEND...WE'RE MAKING THINGS HAPPEN" The strong words of Captain Phil! Rest in peice!

i make sure 2 adjust them while th e motor is completely cold.
could it be lifters stickin??

i dont think that would be the prolbem did you shim the shafts are they stock or solid shafts ball or big foot adjuster like subysteve said make sure you have the flat part to the valve

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drive it like you know how too fix it

i always set mine cold then let it warm up and recheck them and reset if needed,have i been doing this wrong?if you have adjusted these as many times as you say and the screw and jam nuts wasn't backing off you would be out of screw by now.have you checked your pushrods to see if they have bent any at all.i cant see a cam wearing down that quick that shouldnt be your problem.chad

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NOW GAS IT!!!!!

valve lash should all ways set with the engine cold i think 0.006 is the spec but i set mine on 0 if i set for someone i will go 0.006

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drive it like you know how too fix it

before i changed 2 solid shafts with the swivel feet, i was out of screw on #4 and had very little left on #3 and the next time they backed off the jam nut on #4 came off (due 2 runnin out of threads on the bolt) droppin out the screw and breakin 3 rods.
my cam calls 4 them 2 be set at .004 but i usually set mine on 0. they backed off last night and my #1 exhaust had backed off to.015 my #4 is atleast 1/8 in off

did you use the red break in lube with the cam if not then it might be the cam they need to mash togather for proper breakin change the oil see if there is any metal in it

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drive it like you know how too fix it

What procedure are you using to adjust the valves?

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Water cooled Dry Sumped Subaru Powered Turbo Charged Fuel Injected 2500CC Tank. Oh Rah! He who dies with the most Toys not only wins, He also wears them out!

Are you sure your geometry is correct? You may want to check it, that may be why your haveing issues with running out of bolt threads. Are your pushrods the correct lenth also?

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"YOU CAN MAKE THINGS HAPPEN, WATCH THINGS HAPPEN OR WONDER WHAT THE F$$K HAPPEND...WE'RE MAKING THINGS HAPPEN" The strong words of Captain Phil! Rest in peice!

i bring up #1 top dead center on the compression stroke. adjust 1 intake and exhaust turn the motor over counter clockwise half a turn to bring up #2 adjust it half a turn counter clock adjust 3 half a turn counter clock and adjust 4

I'm thinking the cam is going flat.

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Gary

Turbo VW Sand Racer
Polaris Ranger



"If you don't run into the Devil every once in awhile, you must be going in the same direction!"

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Im thinking the same, also if the geometry is that bad mabey it should have lash caps.

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"YOU CAN MAKE THINGS HAPPEN, WATCH THINGS HAPPEN OR WONDER WHAT THE F$$K HAPPEND...WE'RE MAKING THINGS HAPPEN" The strong words of Captain Phil! Rest in peice!

i thank it is cam to if you like to come by my house i would be happy to try to help you with it you only about 40 miles from me

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drive it like you know how too fix it

i took it 2 tim at southern bug yesterday and we tore it down. turns out the pushrods had worn through the lifters. must of been a bad bach of lifters. (never seen that before ) but im pretty happy thats all it was. the cam is still in perfect condition yea 4 me
lol

cool glad it wasn't that major,i couldnt see a cam wearing out that fast but you never know.did you take some pics i would like to see this i have never heard of that either.them some tough push rods lol.chad

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NOW GAS IT!!!!!

cool

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drive it like you know how too fix it

i keep one of the valves ill try 2 get a pic on here later

Thats a first for me too. It would appear they case harden the lifter ends and missed those.

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Water cooled Dry Sumped Subaru Powered Turbo Charged Fuel Injected 2500CC Tank. Oh Rah! He who dies with the most Toys not only wins, He also wears them out!

Scat had a bad batch of lifters for a while. I know several people that had the same problem.

When did Scat have the problem? I've got a Scat cam and lifters that I have n't run yet, they're about 2 1/2 yrs old.
Thanks Dave.

I had trouble similar to that once and it turned out to be the cam gear came loose. it was amazing how good it still ran while I was trying to figure out what the problem was.