This is heart breaking. I have seen dozens of accounts where people have done the same things and often include replacing the starter solenoid, ignition switch and other item when all that was needed was to adjust the valves, spending hundreds of dollars. Did just have one where the starter shaft needed oiling after setting for 2 years.

Instructions on the way.

Walt Conner

Thanks, Walt.

I pulled the valve cover and what greeted me was the intake rocker arm lying off the pushrod and the small valve
cap at the bottom of the valve body. I pulled the intake push rod out (real easy since the rocker arm was out of the way :) ). I am assuming the nice bend in it did not come from the factory.
OK, it was hard starting and ran rough but how it ever started at all with the rocker arm off the push rod and the stem cap off I'll never know. Maybe the valve cover kept it in place enough to push it open. The keeper nut was tight.
My concern is what to do now. I am hoping nothing else got damaged. I am going to continue and pull off the head and inspect the valves and seats.
Any suggestions on what I should look to replace other than the intake push rod?

Usually a loose valve seat or sticking valve causes bent
pushrods.

Fish

Check for cracked rocker arm. A friend just had an OHV twin that was bending push rods repeatedly, finally found that a valve guide had come part way out (inside the valve spring) and the valve spring retainer was hitting the valve guide bending the push rod.

Note that neither valve guides nor valve seats are replaceable on these engines. You are supposed to buy complete new head. My friend did re-seat the valve guide using a thread lock compound. It has stayed so far.

Walt Conner

Well, for a follow-up, I pulled the head cleaned the carbon from the cylinder and head, replaced the valves (lapped then by hand), reset the clearances (per Walt2002's excellent instructions), new push rods and valve keepers.

OK ,now the engine turns over like a charm, starts in a second, idles OK at 1000 RPM (way below the 1750 spec). If I put the throttle at above 1/4 it sounds like it misses and the muffler is missing (VERY LOUD). Tried adjusting carb but no help.
Pulled new spark plug and it was black and sooty, I am assuming rich.

Pulled carb tonight and overhauled it.
Will install it in the morning and reset linkages and idle screws to spec. Maybe not feeling too confident at this point but is there anything else I should look at?

Remove the valve cover again, and watch the valves while
you turn the flywheel by hand. It sounds like you still have a sticking valve or something.

Fish

If you bent a pushrod on an engine that has been running a while, you had a valve stick. Likely due to old/bad/stale fuel. It doesn't take a lot to stick the valves and bend the pushrods in a lawn tractor engine, regardless of brand.

A friend's engine sounded like that and he found that the new push rod he had just put in was also bent. After bending still another one, he found that a valve guide had come part way out and the valve spring retainer was hitting it bending the push rods. Might want to compare the height of the Exhaust Valve Guide with the Intake Valve Guide.

He re-seated the Valve Guide with a thread lock and it has stayed so far.

There was another incidence of this on one of the lists I monitor and we know of still another in a neighboring town.

Walt Conner

OK, I put the carb back in and it starts up right away. Got it to idle OK and it sounds good. However, as soon as I advance the throttle it appears the exhaust start to back up through the carb (I've got the air intake/filter off) and needless to say is very LOUD.
I do notice that when I rotate the engine manually and watch the valves the exhaust valve moves much less in relation to the intake valve. Since this is the first Briggs I have taken apart I assumed this is OK.

Any suggestions?

"watch the valves the exhaust valve moves much less in relation to the intake valve. Since this is the first Briggs I have taken apart I assumed this is OK."

NO, did you check the Exhaust Valve Guide as I suggested above?

Walt Conner

How do I get in touch with someone who posted an answer to this problem. I am a rookie when it comes to working on these machines. I read a posting by "walt2002" and was very interested in it. Which valve is the intake valve (upper or lower) and which is exhaust? What is the correct clearance? Manual tells me one thing and repair tells me something entirely different. Thanks.

The TOP valve is the Exhaust Valve. The correct clearance is .003" to .005" for the Intake and .005" to .007" for the Exhaust.

I have detailed instructions for adjusting valves IF you would like them.

Walt Conner
wconner5 at verizon dot net

Hi Walt,
I checked for an extended valve guide but it looks OK. I can also compress the exhaust valve by hand.
However, when I turn the flywheel the exhaust push rod only moves about 1/8" whereas the intake push rod moves about a 1/2". My thought is that as the engine speeds up the exhaust valve is not opening up enough (or the travel time from open to clost is too short) that not all the exhaust gas is allowed to exit the chamber thus backing back through the intake port/carb.
Now the only thing I can think of is that the cam lobe for the exhaust valve is bad or the tappet is somehow damaged thus only allowing the push rod to move a small amount. Either way it appears that I will have to open up the crankcase to check.
Any other thoughts?

"Any other thoughts?"

No, sure sounds like cam shaft is bad. I have never had this but have heard of it.

Don't know if I have a spare cam shaft for this or not.

Walt Conner

Thanks, Walt. I think I will pull the beast and pop the crankcase and take a look see. I did find on the internet a reference to a problem that B&S was having with some of their Intek camshafts wearing permaturely. A new one from B&S is $40 so not too bad. Will update what I find.
Thanks again!

At TDC both valves and pushrods are at the same height?

The pushrod that barely moves, are you sure it is in the
tappets socket correctly?

Fish

Fish,

I checked and the push rod is in the tappet.
At TDC the exhaust push rod is about 1/16" (if that) below the intake rod.
From TDC to the maximum push rod movement the intake push rod moves out about 1/4" whereas the exhaust push rod extends move out about 1/16".
I don't know exactly what the lobes on the cam shaft look like but I assume they should be fairly close in size to each other. My hunch is that the exhaust lobe may be damaged somehow not allowing the exhaust valve to stay open long enough to properly exhaust all gases. I haven't popped the crankcase yet but I understand the cam lobes are made out of some type of composite material. Possibly wore prematurely?

"I don't know exactly what the lobes on the cam shaft look like but I assume they should be fairly close in size to each other. "

I think that is a good assumption. The cams are typically cast iron, I have heard of some not having the lobes hard surfaced or something thought I have never come across it.

Walt Conner

OK, I pulled the camshaft and the intake lobe is worn almost round! A 1/4" difference between the exhaust and intake lobes. Interesting though everything else looks fairly clean. Even the tappets show only minimal wear and no cupping
B&S online is out of stock for the camshaft (wonder why?). Any suggestions for other suppliers?

Neighborhood small engine repair shop may have a good used one from blown engine. Large shops generally don't fool with used parts. As I said before, I MIGHT have one, does yours have an oil filter or not?

Walt Conner

I have the same problem with a replacement engine on a Bolens "big box store" tractor.My engine has less than 10 hours since new. Does anyone know what the cam lobe lift should be on this engine for the intake and exaust?... Ken

I had the same problem on an old 12HP tecumseh engined Dynamark i bot off a freind - it turned by hand, cranked, but wouldnt start. Keep in mind, this thing sat for like 5 years in his barn because it just quit one day when he was mowing. So after more investigating, and advice from a gearhead freind, he said adjust the valves a bit. Lo and behold, the one rocker arm was laying in the bottom of the cover. I lightly tightened it back on and hand spun the motor, it seemed to open n close fine, no aparant damage. I noticed that even tho theres a nut holding the rocker on, it seemed to back off while messing with it. I bot a engine rebuild book and it says it should have 2 nuts on both ( to lock it) - i got a lil creative, i found a couple nuts in my parts bin that threaded on the studs, since its a tight fit under the cover, i used a grinder wheel to make em skinnier. It worked, it never came apart after that, and after a carb replacement ( old one was all messed up) , it fired right up and ran actually pretty good.
Kidd

UBI The replacement cam for the cast intek cam went to a comp cam- at least the one I was fortunate enough to do last year. . .

Okay. I have now run into the Intek engine from hell. Would not run, adjusted the valves, started fine 2-3 times, then would not run. Adjusted the valves again -- they seemed set from the last time with minor change. Cranked it several turns then started.

sigh.

Walt202...could you send me those detailed instructions you have to verify I have ste the valves properly?

Check the rocker arm studs for tightness, they are a problem too.

"Walt202...could you send me those detailed instructions you have to verify I have ste the valves properly?"

Not here, too long. Email me at (put in proper order)

wconner5 at verizon dot net

Walt
Can you email the valve instructions also?

Use blubboman2000 AT hughes DOT net

Thanks

blubbo,

Tried your address and it bounced, Mine is just above your request.

Walt Conner

OOPS

The correct email is blubboman AT hughes DOT net. Got it confused with another email address. Sorry

I think I've got running ok. I adjusted the valves, although I did it backwards the first time. I had .004 at the exhaust and .006 at the intake. It started a little hard but did start. After about 2 minutes running, it suddenly ran rough and puffed out some white smoke. I shut it down and put the valves back at .006 exhaust and .004 intake. It started easily and ran ok for almost 10 minutes. I did also clean the white plastic clutch shaft on the starter so the gear would withdraw easier. I think it's ok! Now I just have to clean the deck.

Walt could you email the instructions to me?

Walt my address is greg AT netrixsolutions DOT net

can somone help me and tell me why my tractor is bending push rob's and i replaced them and then and worked fine and then it wouldent start and it was blowing oil out of the carb and bent a push rod why is it blouing oil out of the carb and how can i fix this problem and why dose it bend push rods

my tractor is blowing oil out of the carb and i had to replace the push rods and then it worked fine for a bit than it bent a push rod and it was blowing oil what it causing this to happen

Well Fish says to check that the rocker arm studs are tight in the head. If that doesn't turn up the problem, check the height of the valve guides. I take it the engine is doing this on the same cylinder, same valve? Sometimes the valve guide comes loose on these and work up until the valve keeper hits the top of the valve guide bending the push rod. This is not repairable according to B&S. Some have been having problems with the valve sticking in the guide causing push rods to bend.

IF your "unrepairable" valve guide is the problem, email me for fix.

Walt Conner
wconner at verizon dot net

I think I may be experiencing the same problem. It seems that my 18.0hp intek will not turn past TDC on starting. Problem was intermittent but now does it every time I try to start the engine. I am hoping that adjusting the valves will solve this problem. If someone could e-mail me the instructions for adjusting them I would greatly appreciate it.
stu925 at earthlink dot net

Why do I only want engines that begin with H or K?

im having the same problem ..i see no visible damage or bends...however the cylider pressure is coming out the intake for a split sec....and reverse for the exhaust.... the timing seems to be wrong on the valves,how can i adjust this?

I also have a post here, my compression when cold is OVER 155psi when cold. WAY too high, but the valvetrain is OK, clearances are correct, and I can see the valve for the compression release working. Any thoughts?

Walt could you email the instructions to me?
safartl at yahoo dot com

Walt, if you are still a part of this forum, could I trouble you with getting a copy of the valve adjustment instructions and if you have them, the torque specs and bolt pattern for the head?
Great posting of info for this Intek.

Thanks Walt.
Brian
bcsimonet@netscape.net

I already posted my email address several posts up.

Walt Conner

Walt
Can you send me those instructions??

smith1ao@yahoo.com