Briggs 14hp IC not running right

[Freddie21]

Try a governor static adjustment. loosen the clamp on the governor arm, hold the throttle all the way open, rotate the governor arm max CCW and tighten the clamp. Compression test may show the issue.

 

[Forest#2]

We have people on this site that knows small engines in and out but we NEED to have the EXACT model, type and code from the top of the valve cover.

We have asked you several times for this info but it just falls on deaf ears.

Can you tell us why you cannot give up this info?????

Excuse me if I have overlooked you posting such already.

 

[Chris_feldk]

Yeah i have it just kept forgetting to write it down. model is 283h07 Type 0197E1 Code is 0403087E
I pulled the head today and saw a crack by the intake port and thought that was the reason why is runs like crap so i took a spare head off a parts motor i had and cleaned it and lapped the valves. Then put it on this motor, and nothing changed still runs like garbage. Also has 75psi of compression. But i did notice though it looks like the intake valve doesn't open very far so maybe that's why? I'm not sure but this has got me stumped and ready to cut my losses

 

[Chris_feldk]

Try a governor static adjustment. loosen the clamp on the governor arm, hold the throttle all the way open, rotate the governor arm max CCW and tighten the clamp. Compression test may show the issue.

I would but the governor isn't the issue it never moves the throttle. It stays wide open and is never pulled back.

 

[Chris_feldk]

Here is a link to a video of it running and what it does. (Click here) it needs to have the choke on then you can put it wide open then shut the choke off but it still is running way too rough and slow.

 

[Forest#2]

You eliminated quite a bit of stuff.

What I would think about doing is check the valve lift. compare the exhaust push rod left to the intake. Compare the lift of each to each other. Look for as much as 1/4 inch difference in lift height, I've seen one lobe loose enough lift on those 28 engines, especially the intake and the compression release still operate but not get up to speed and sometimes detect by ear a sputter through the carb throat.
(why, I've seen a lobe wear down to where lift would not be correct)
You can find exact specs for the lift in a search.

You say you have adjusted both valves to around .005 but the lift on the intake looks suspicious.
If you find the valve lift ok check the flywheel key.
In your first post it appears as though you have never seen this motor run good. (you got it as a used motor to swap onto a mower)

Have you checked the magneto air gap as being .010-,012 and swapped the ignition magneto and also checked with the proper spark plug?
I've also seen ignition modules do strange things.

Do not operate that engine over about 15 seconds with the air cowling off, they will overheat fast.

 

[ILENGINE]

You eliminated quite a bit of stuff.

What I would think about doing is check the valve lift. compare the exhaust push rod left to the intake. Compare the lift of each to each other. Look for as much as 1/4 inch difference in lift height, I've seen one lobe loose enough lift on those 28 engines, especially the intake and the compression release still operate but not get up to speed and sometimes detect by ear a sputter through the carb throat.
(why, I've seen a lobe wear down to where lift would not be correct)
You can find exact specs for the lift in a search.

You say you have adjusted both valves to around .005 but the lift on the intake looks suspicious.
If you find the valve lift ok check the flywheel key.
In your first post it appears as though you have never seen this motor run good. (you got it as a used motor to swap onto a mower)

Have you checked the magneto air gap as being .010-,012 and swapped the ignition magneto and also checked with the proper spark plug?
I've also seen ignition modules do strange things.

Do not operate that engine over about 15 seconds with the air cowling off, they will overheat fast.

You are correct. Lobe worn on the camshaft will limit valve lift and will act just like a governor and limit the engine rpm even with the governor spring holding the throttle plate wide open. The one I had in the shop limited the engine rpm to around 2000 rpm.

 

[Chris_feldk]

Just check the flywheel key today, it’s not sheered and yes I only had the shroud off for the 20 seconds to show the carbs throttle movement. I did adjust the valves (intake .004 and exhaust .006) and did see that the intakes lift seems suspect and maybe that’s why it runs like this. And yes i gapped the magneto at 10 thousands and verified it is indeed the correct plug. I will find a spare coil off of one of my parts motors and swap them out. And the engine only gets to about 2000 rpm so this seems like what my issue is. Do you think I can take the crankcase vent off and stick a borescope in there to look at the cam or should I just pull the motor and open it up? Thanks guys I appreciate it.

 

[ILENGINE]

Just check the flywheel key today, it’s not sheered and yes I only had the shroud off for the 20 seconds to show the carbs throttle movement. I did adjust the valves (intake .004 and exhaust .006) and did see that the intakes lift seems suspect and maybe that’s why it runs like this. And yes i gapped the magneto at 10 thousands and verified it is indeed the correct plug. I will find a spare coil off of one of my parts motors and swap them out. And the engine only gets to about 2000 rpm so this seems like what my issue is. Do you think I can take the crankcase vent off and stick a borescope in there to look at the cam or should I just pull the motor and open it up? Thanks guys I appreciate it.

The intake and exhaust valves should have the same amount of lift. So if the intake is opening half as far and/or half as long as the exhaust then you have a camshaft lobe wear issue.

Just make sure to check the condition of the push rods. The push rods can collapse which will also effect valve lift height and duration

 

[Chris_feldk]

Swapped out the intake rod with one that looks ok, and reset valve lash and the valve lift looks ok, runs a little better.. but still running about the same rpm. I'm most likely going to bet its the cam at this point.