Valve clearance

[mmoustafa]

Hi all,
After measuring my valve clearance with a feeler gauge the exhaust cleanse is under at .006” (spec is between .007-.009”).
I couldn’t get a good reading on the intake side because it was so tight (spec is between .005-.007).
My question is how critical is it to have a gap? And what problems could I possibly encounter with too tight a clearance?
Regards.

 

[ILENGINE]

The main issue is the valves may not close all the way causing valve floating and loss of compression, low power, hard to start.

 

[Fish]

The lessening gap is caused by heat warping the block and the valve seat area is coming back slightly. You need to remove the valves and grind the stems a hair until they are back in spec, or the heat/warping will just accelerate.
I wouldn't worry about lapping or anything like that, as it would take regrinding the valves and seats to correct the warp.
Removing the valve springs can be tricky without the proper tools, but look on youtube, you will likely see some good ideas {and many,many chitty ones}.

 

[Scrubcadet10]

Made removing L head valve springs alot easier, https://www.amazon.com/gp/product/B001OK9TRK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[mmoustafa]

Thanks for the replies.
I ground the stem down using some sandpaper, lapped them in and reinstalled them (using cable ties - a trick I saw online but definitely want to invest in the actual tool).
Then after installing the head I realised the springs are in the opposite orientation (one has the tighter side on the bottom while the other on the top ?), Is there a correct orientation? And does this matter much ?
Regards.

 

[bertsmobile1]

The closed coils go to the bottom .
Now it does make a difference on a motorcycle engine doing 8000 rpm.
wether it is significant on a side valve mower engine running at 3500 is a different matter & i doubt if it would
The open coils at the keeper end would make the engine easier to assemble & I suggest that is why they use a progressive spring.
It also prevents resonance in the spring but again at mower speeds I can not see that being a problem.

 

[mmoustafa]

Thanks [B]bertsmobile1[/B], I ended up correcting the orientation of the valve springs.

So after assembling my 4 stroke B&S mower engine (Model 95902), I noticed the flywheel isn't rotating smoothly by hand.
It's easy enough until I get to the intake stroke then it gets stuck and requires more force.
I compared it with my dad's mower and his one rotates smoothly with momentum throughout!
After some research online, I found the problem could be:
1. not enough valve clearance
2. over tightening of the connecting rod cap

Does anyone have any other suggestions or could there be other causes?
Has anyone encountered a similar problem before?

Regards.

 

[Scrubcadet10]

What was your final valve clearance reading?

 

[mmoustafa]

Exhaust = .0035"
Intake = .006"

I also overfilled with engine oil which i plan to drain later but didn't think that would affect the operation.

 

[mmoustafa]

https://kapwi.ng/c/h2E2RsQR

Hi again, the link above shows a video of me trying to rotate the flywheel and you can see how it’s getting stuck.
I know my valve clearance is out but I didn’t think it could create this problem?

I’m thinking to grind the stems again to get the clearances to spec but am wondering if there is a deeper issue here?

Any ideas/ suggestions?