head messed up. please help

i have a 1987 warrior 350 with about 7 hours on engine rebuild. (rebuild was done by previous owner)

the quad ran fine but had a ticking rocker, it was the exhaust side and the only way to get it to stop ticking was to tighten it a little over spec.

i rode for about 3 hours straight and while running wide open in 6th on a paved road it sputtered a couple times and died like the ignition was cut off.

i got it home and turns out the exhuast side rocker is almost siezed on its shaft to the point where it takes a pry bar to move it up and down. (it was holding the valve 1/4 of the way down until i pryed it up) the valve is also bent from it hitting the piston. the piston is fine.

what could have caused this? when i removed the cam from the head the head was completely filled with oil so wouldnt think it would be an oil issue- also the intake rocker and shaft are in perfect condition.
could the overtightened valve lash have caused this? stretched timing chain? timing off/timing jumped a tooth?

i purchased a good used ebay head, i am going to install a stage 2 hotcam, and a new cam chain. and make sure the valve lash is perfectly within spec. will i be a-okay then?

i just want to know what could have caused it before i put all these parts in and it happens again.

i cranked the engine over (head off) via the starter and after about 20-30 seconds of cranking oil was pouring from one of the head bolt holes.

thank you very much for helping me as i am new to the forum.

Yeah, with the new stuff you should be good if the head is now getting plenty of oil up top. This quad is new to you so perhaps before it was yours it was ran will little or very old oil? Perhaos gunk gummed uo the rocker oil gally and starved it?

I believe the rockers can come out of these heads, yet, I don't think anyone sells new ones by themselves. You might be able to find some on fleebay.

If the rocker is siezed those parts won't fix that problem. You can replace the rocker but you need a slide puller to get the shaft out. After all is said & done you may be best offv to find a good head.

its easy to pull rockers out its a metric thread from inside the cam chain cover but you have to pull the head bolts out to the to them and the can bearing keepers i think you got a bad oil pump and floated the valve on it it is possible to do on oem cam change valves and springs to good aftermarket and change the rocker to a new one and check the oil pump after its all re assembled

'00 WO-YA! said:

After all is said & done you may be best offv to find a good head.

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He said he got a new one......and a cam and new chain.

DeadLastRacing said:

He said he got a new one......and a cam and new chain.

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Deadlast is right. I bought a good used complete head off fleabay. I ordered a new stage 2 hot cam, cam chain, and top end gasket kit.

I checked the oil pump by cranking the engine over with the head off and oil spewed out of a head bolt hole.

Do you guys think i will be okay? I will put in a brand new filter with yamalube 10w-40.

And your right the quad is very new to me this was my first time riding it. The guy had crappy citgo 10w30 in it but the level was fine and it seemed clean on the dipstick. Maybe the crappy oil had something to do with it?


The cam is on backorder and the head hasnt arrived yet, i have everything else. I just want to make sure it should be okay with all the new parts or is the problem elsewhere?

I really dont want to buy an oil pump (expensive) and a clutch gasket if the pump is okay and i dont need replace it. From the volume of oil that spewed out i would think its okay?

Thanks for all the replies

keep me posted cuz what happened to you...the exact same thing happened to me last week on my 87' warrior

pens3529 said:

keep me posted cuz what happened to you...the exact same thing happened to me last week on my 87' warrior

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Really? Same exact thing the exhaust rocker siezed? Mine happened sunday

Ill definatey let you know what happens. I found alot of used heads on ebay would you like me to pm you the links?

I feel your pain this sucks :argh:

Change to kibble white valves and springs other wise its going to float the valves again specially with that cam

duneracerweston said:

Change to kibble white valves and springs other wise its going to float the valves again specially with that cam

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Do you think thats what happened? Could that have caused the rocker to sieze? Where can i get the kibblewhite parts?

Your first warning was having to run too tight of valve lash. If you have to choose, loose is better than tight.

How much chunky funk is on the filter and in the screen?
I'd imagine the filter is/was plugged, then starved the top end. That's what happened with mine (bought it that way). Both rockers had galled the shafts, beat the adjuster screw tips, siezed the cam bushing to the cam, burned the big cam bearing brown and wiped out the cam lobes. Strangely, the thing ran fine with plenty of power.

I'd pull the clutch cover along with the oil filter and douche the daylights out of the passages with some brake cleaner, kerosene, hot soapy water and a toothbrush... anything. Keep it off of the clutch pack though. You may be surprised at what's laying in the bottom of the trans...

You say it took 20 or 30 seconds??? Man, that's waaaaay too long to get oil up top. It should be almost instantaneous. You have an oil delivery problem, not a valve spring problem. You need oil volume, not pressure. What may look like "a lot" of oil may not be "enough".

Don't forget to check the small inner cam needle bearing while it's apart too. And the piston contacting the valve can lead to small crown cracks, and/or a bent connecting rod.

I'd look into one of Midway's heads before you go too far...

Sorry, I spoke too soon, it seems like this thread is covered though, good luck with your project.

the head finally came from ebay and the same rocker was already siezed, exhaust studs were broke. i got my money back. now looking for another used head.

warrior35087 said:

the head finally came from ebay and the same rocker was already siezed, exhaust studs were broke. i got my money back. now looking for another used head.

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Got one ported and ready to go. Look in the for sale section.

MotoArts said:

Your first warning was having to run too tight of valve lash. If you have to choose, loose is better than tight.

How much chunky funk is on the filter and in the screen?
I'd imagine the filter is/was plugged, then starved the top end. That's what happened with mine (bought it that way). Both rockers had galled the shafts, beat the adjuster screw tips, siezed the cam bushing to the cam, burned the big cam bearing brown and wiped out the cam lobes. Strangely, the thing ran fine with plenty of power.

I'd pull the clutch cover along with the oil filter and douche the daylights out of the passages with some brake cleaner, kerosene, hot soapy water and a toothbrush... anything. Keep it off of the clutch pack though. You may be surprised at what's laying in the bottom of the trans...

You say it took 20 or 30 seconds??? Man, that's waaaaay too long to get oil up top. It should be almost instantaneous. You have an oil delivery problem, not a valve spring problem. You need oil volume, not pressure. What may look like "a lot" of oil may not be "enough".

Don't forget to check the small inner cam needle bearing while it's apart too. And the piston contacting the valve can lead to small crown cracks, and/or a bent connecting rod.

I'd look into one of Midway's heads before you go too far...

Click to expand...

got any pics to help me with this???

Well, err, no.
Pull the covers, filter and drain plug with screen and let us know how much black funk is laying on the bottom of everything. Is the oil filter black and sucked inward? Mine was, and full of chunks of what I assume are fine clutch fiber pieces and (more likely) dirt from that stupid, non-filtered :-0 crankcase vent going up to the airbox.

I would imagine that is what is seizing the rockers on most all these engines, lack of frequent oil changes with filter replacement. I'll bet they all could benefit from a good crankcase flush job.

Sure wouldn't hurt to inspect the pump while the cover is off like duneracer suggested. If the pump's toast, then all of your work will shoot right out the window soon as you fire it up. I rolled the dice on mine by not pulling it, and things have worked out well so far, luckily. I don't honestly know if the pump is even serviceable (to check for scoring, etc.) or not. It's your choice though.

Let us know what you find.

I did find one pic.
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The bad cam is on the left. Lobes are ground down about 1/32" where the rockers chewed into them. You can see the shiny "edge" on the lobes. The small journal end, at the bottom of the pic, still has the bushing fused to it. You can see where it is burned brown on the edges. This fits into a needle bearing inside the head itself. Cam rolls in bushing on oil film, bushing rolls in bearing. This'n here quit rollin' long ago.

The cam on the right has some minor rust pitting on the lobes, but is otherwise nice.

when I took the oil out it was thick and balck...the filter was clogged....I changed the one way bearing and there too the oil was the same....so I'm getting all info together then I'll attack to open it up....this will be my 1st time doing this so I want as much info as I can before I do this

Sounds to me like it wasn't oiling because it couldn't get oil through the filters jmtc

so in your opinion do you think it's only the valves the are the problem (top end) or I blew the motor (bottom end)??