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Discussion Starter · #1 ·
Hi there new to the site hope someone can help with this .

Got a 20hp Vangaurd engine model 135877 got a small crankcase oil leak ,it was starting ok with the leak but then wouldn't fire up again . Have replaced the crankcase gasket never moved anything just lifted the case like normal.

This is the problem went fire it up the starter gear has stuck to the flywheel on inspection everything went the way it should. Disconnected the drive belt of the pulley . The engine seems to have excess compression can turn it over by hand but very hard.

Any info guys please. John
 

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First off, welcome to MLF! :mlf: :howdy:
Are you sure that you didn't change the position of the camshaft in relation to the crank shaft? The resulting mistiming might cause the engine to be hard to turn over.
 

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Also check your valve adjustment. When the valves get too far out of adjustment the ACR(automatic compression release) lobe on the crankshaft will contact the pushrod but the space between the rocker and the valve stem will not allow the valve to be opened with the smaller lobe pushing it. The normal operation lobe will open and close the valve and make everything seem normal until you try to start it.
 

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Discussion Starter · #4 ·
difficult vangaurd

Thanks for the reply,

I'm dead sure I haven't moved anything when I took the crankcase off that was my main concern not to move anything.

Would that have the valve issue happen before I fixed the gasket problem .

As I was starting with the leak then it would not fire at all .As we had been trying start it the leak crankcase would have that cause the loss of compression and thrown the valves out of order.

When it was running or even trying to start oil would spit out the crankcase when I done the gasket there was only 1 spot of 10cm of old gasket blown out would that be cause from the compression issue too.

john
 

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IMO..your compression release thingy on cam is broken...How? maybe it was partially broke before you opened up sump..slight wobble of cam..then gone..After valve adjustment, you may not be able to see the momentary bump of the intake valve during compression stroke...proving you'll have to 'go inside " again..replace the cam..
 

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Discussion Starter · #6 ·
20 Hp Vangaurd

Thanks for that info,

Think that thingy must to have gone before I open the sump cause if that throws the valves out , That explains way it would not fire in the end.

As to the valves haven't looked at them only done the crankcase gasket put the engine back on & tried to start it but nothing happen the flywheel hardly turned that when I took the belts off & sparkplugs out tried to turn it by hand it was very stiff.

I'm thinking it maybe cheaper to put a new engine on as this one has about 1000 hrs on it .

Cheers
john
 

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Well, it depends on how much wear the internal components have. It might be worth it to pull it apart and take a look at the crank, rod, bore, cam, etc, and see what kind of shape they're in. If they're not too worn, it might be worth it to overhaul the engine and fix whatever needs to be dealt with. However, since the engine has plenty of hours, it might just have a lot of internal wear and might be needing replacement.
 

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JUst to clarify---If the compression release thingy is broken...It will NOT stop the engine from firing off..it will merely cause the starter motor to struggle or stop the cranking....engine will still run as good as it did prior..However, if you find engine is hard to turn by hand with the plugs removed...recheck that your starter "gear" has released from the flywheel....if so...you prob have internal problem...From what I heard...1000 hrs is Not end of life for a Vanguard ...prob repairable..
 

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Discussion Starter · #9 ·
20 Hp Vangaurd

Thanks again guys

The starter was my first thought the other when we first tried to start it was stuck to the flywheel .got it free but hit the key same thing was happening ,

So when it was unstuck we removed the belt & sparkplugs turned it by hand found how tight it was .

We'll keep you guy's informed of what we find.
 

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You took the sump off before, correct? Sounds like something was put together wrong and somethings rubbing somewhere. Lower oil seal?
 

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Maybe everything inside is still ok...You need to "clarify" how tight engine feels by hand turning after starter gear is free of flywheel..and whether it is tight turning thru all 4 strokes...or just on compressions strokes...confusing to me is when you say "hit the key", are you trying to start [ie spark plugs are back in]..or merely crank it..? Obviously if spark plugs are out, No tightness should be felt..either with starter or by hand,,and won't matter if valves are adjusted properly at this stage...Assume this is a V-Twin...You should pull both valve covers by now...observe the 4 push rods moving..and the rockers ...What are the type & code numbers..?
 

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Discussion Starter · #12 ·
vangaurd 20hp

The Mod is 135877 Type is 0280-E1 code 03050911

Yeh its a v twin engine

What I meant with key tried to start it before trying anything else at first. Next step was removing the sparkplugs to try compression .

John
 

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Discussion Starter · #13 ·
Vanguard 20 Hp

Hello Guy's

We have decided to go back inside the engine an have a look . What is the correct valve setting for this engine and if needed how do we set the camshaft timing ??
 

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You don't set valve clearances inside the engine, you set them under the rocker cover. Camshaft timing marks should be aligned, not sure if the Vanguard is the same as a regular Briggs engine.
 

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How do you set camshaft timing? Carefully ! Ha!
It won't matter...you should be going back inside to simply locate what is causing the "friction" when you turn eng by hand [with no sparkplugs installed]...Counterweight ?
Also...I would certainly [as mentioned], pull those valve covers and be sure pushrods and rockers are normal..and agin..final lash adjustmnet won't matter, yet..
 

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Did you ever take the connecting rod caps off? Make sure they are not overtightened as that will definitely cause the engine to seem seized or tight.
 

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Discussion Starter · #19 ·
vanguard 20 hp

Hi Guy's

Open is crankcase again today first found the small gear on the crankshaft was sitting up relined all that bit , Then that compression valve thingy was most of the trouble it was all intact .

Anyone knows how that lever in the governor rod works ?? does it sit down on top of that compression valve . So when the valve is open this lever on the governor rod pushes up to close it .

Or does fit in under flange of this thingy. ???

put the case back on it easy to turn over now by hand but concerned about the arm on the governor rod .

Checked the valves the rocker are pretty tight are the valves set at 00.4 on this model ?

Thanks for you info guy's
 
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