Husq 2348 Intek V-Twin Compression Release problem

TheWatfordFox

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Nov 13, 2011
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Need some help please on my Briggs and Stratton 23hp V-twin

- Model 445577
- Type 0755 E1
- Code 061129 YG

Despite having a fully charged battery, working solonoid, and working starter, my engine is reluctant to turn over. When I turn the key it tries to turn but is obviously inhibited, feeling like somehow there is resistance in the system. It turns over fine if I remove the plugs

I've done a little research and it seems that the likely issue on my 5 year old machine (around 500 hours) is compression release. My understanding is that it is normal practice to adjust the valves, but to be honest I have never done this at service, and have limited myself to changing the oil, filters and greasing

I'd be really grateful if any of the experts out there could walk me through the procedure please. I'm reasonably handy, but not an expert
 

ILENGINE

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Don't see the valve adjustment issue very much on the v-twins, it is mostly the single cylinder 14.5-18.5 hp engines. What I do see more on the twins is either the compression release spring breaks, or the flyweight sticks, or the lobes on the camshaft wear down and don't open the valves. All three of these conditions require camshaft replacement.

All three conditions will act like the compression release isn't working because it's not.

To check it remove the valve covers and turn the engine over by hand watching the valves to make sure the fully open and close. If the compression release is working you will see it bump either the intake or exhaust valve open just before top dead center compression stroke. If the valves don't fully open replace the camshaft. If the valve doesn't bump open as described replace the camshaft.


Also check the valve clearances to be sure. The clearances are .004-.006 inch. Roll engine over to just past top dead center compression stroke on one cylinder and insert a feeler gauge to check clearance. do same to other cylinder. The adjusters may either be a lock nut that you loosen then adjust clearance with inner nut, then retighten lock nut. or will have a single nut with a torx head screw in the center. Loosen nut, back torx screw out insert feeler gauge turn nut to proper clearance and then retighten torx screw to snug. Do not overtighten because can crack main nut.
 

TheWatfordFox

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Many thanks for the above. I'll give it a whirl :smile:
 

TheWatfordFox

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Problem solved.

Spent four hours in my garage tweaking the valves as per the advice from my friend from Illonois, and confirmed by a procedure from Briggs and Stratton (attached)

I'm now convinced that compression release was the root cause to my problems.....

- tractor wouldn't start
- checked battery - it was fine
- checked solonoid - it was fine
- checked for a good earth - fine
- checked starter - the nylon gear was damaged
- repaired starter motor - see my posts above
- tractor started once, but then refused to start, seemingly encountering resistance (felt very much like a weak battery)
- did some research and found out about compression release - had never heard of it till then
- I suspect the compression problem caused the damage to the starter motor. Starter was trying to turn the engine over, met resistance, chewed the nylon gear

So glad I have solved it. One problem I did encounter was trying to get the valve clearances to .004 - .006. Is there a trick to this ? Took me 3 hours of tightening and untightening before I got it right
 

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tcmo2011

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For a Husqvarna YTH2348 Intek V-Twin how do I manually roll engine over to.....


"Roll engine over to just past top dead center compression stroke on one cylinder and insert a feeler gauge to check clearance. do same to other cylinder. The adjusters may either be a lock nut that you loosen then adjust clearance with inner nut, then retighten lock nut. or will have a single nut with a torx head screw in the center. Loosen nut, back torx screw out insert feeler gauge turn nut to proper clearance and then retighten torx screw to snug. Do not overtighten because can crack main nut."
 

ModernMower

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The Briggs V-twin in question does NOT have a compression relief valve on the camshaft. I cared to clear that up since folks might be searching for answers here. Adjust the valves, the valves are almost certainly the problem, we see it quite regularly. rarely is it the camshaft itself on a briggs twin, but it can happen, however there is no spring on that camshaft, and no weight. set the valves first, its going to fix it 99 times out of 100. the other 1 out of 100, its the camshaft - but that's allot more rare. (and indicates the probability of other wear related issues)

valve adjustment issues are common on all of the briggs over head valve rider engines, no matter the horsepower. camshaft replacement is more often required on the briggs singles. easy to check - see if it opens one of the valves a tiny bit on the compression cycle. you might need to hold the rockers against the push rods to check it, because the valves might be so loose its tough to see otherwise. a very basic check, is to just see how loose the rockers are when the valves are closed by hand. if they are very sloppy, its probably just an adjustment. just to be clear, the compression relief refers to ONLY briggs singles, not twins. if its a twin, adjust the valves.

we work on perhaps 1000 of machine a year here.

the singles have the centrifugal weight on the shaft, not the twins.

Brian, Shop Owner

Don't see the valve adjustment issue very much on the v-twins, it is mostly the single cylinder 14.5-18.5 hp engines. What I do see more on the twins is either the compression release spring breaks, or the flyweight sticks, or the lobes on the camshaft wear down and don't open the valves. All three of these conditions require camshaft replacement.

All three conditions will act like the compression release isn't working because it's not.

To check it remove the valve covers and turn the engine over by hand watching the valves to make sure the fully open and close. If the compression release is working you will see it bump either the intake or exhaust valve open just before top dead center compression stroke. If the valves don't fully open replace the camshaft. If the valve doesn't bump open as described replace the camshaft.


Also check the valve clearances to be sure. The clearances are .004-.006 inch. Roll engine over to just past top dead center compression stroke on one cylinder and insert a feeler gauge to check clearance. do same to other cylinder. The adjusters may either be a lock nut that you loosen then adjust clearance with inner nut, then retighten lock nut. or will have a single nut with a torx head screw in the center. Loosen nut, back torx screw out insert feeler gauge turn nut to proper clearance and then retighten torx screw to snug. Do not overtighten because can crack main nut.
 
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