OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Briggs and Stratton 14.5 OHV motor

A mate dropped of his Yardman rideon this morning saying it wasn't running properly and was smoking, nothing unusual with this it is a Briggs.
I fired it up with the air cleaner off and it ran for a few seconds and then it squirted fuel maybe 3/400mm into the air out of the hole in the air cleaner base as indicated by the arrow in the picture. Anybody have an thoughts on the cause of this, my assumption is a problem with the inlet valve allowing compression to leak back into the inlet manifold. Any other thoughts?

Hi Norm

Head gasket has had the richard, but check valves first

Compression is leaking into the valve chest (blowing oil out breather and sucking oil into bore)

All too common occurrence with these things

Thanks Tyler,
You nailed it , I haven't pulled the head yet but some dog has had all this apart and there is bodged up bolts everywhere
I got the head off, silicone everywhere all over the gasket. No obvious sign of gasket failure into the pushrod tunnel so still not sure where the crank pressure was coming from. Very minor dip in the head and the barrel at the tunnel faces but only visible with a torch on the other side of the steel ruler. I'm pretty sure a bit of extra tension on the head bolts on that side would close it up
Seeing you are aware of the problems with the head gaskets Tyler, have you heard of any tricks to try preventing the issue.

With the head off it is obvious that this motor has had a recent rebuild. My mate has just bought this machine and what I can't work out why he was not told anything about this work having been done. New piston, cross hatching clearly visible in the bore and there is no sideplay in the piston so why would somebody go to all this expense and work and not say a word about it to my mate. My mate doesn't know a lot about motors but is an amazing panel beater/spray painter who does the most beautiful restoration work on classic cars, he is top of the class in that area and I guess you get that way after doing this stuff for 50 years

That head gasket looks like it's done Norm. That's one of those graphite? type gaskets and it looks like it's delaminated.

Hi BT,
Hard to tell with the gasket, I had a big job to lever it apart, it had been put on with mountains of silicone, the same as the rocker cover, silicone everywhere. From what I could see there was no damage to the gasket between the head chamber and the push rod tunnel, but I guess the only way to find out is put a new gasket in and see if that eliminates the crank pressure.

Just looking at this head design there is too much gap between the head bolts on the side where the pushrod tunnel is. One stud in that area would save all the issues with head gasket failure on these motors

All to save 2.75¢ per engine and not save headaches for owners. Typical Americans.

Bit like manufacturers using steel welsh plugs in cars knowing they would need to be replaced down the track or worse still end up cooking a motor. All for the difference in cost of fitting steel plugs instead of brass ones

Before I wrote off my Commodore years ago, I was facing a $900 repair to replace the Welch plugs which required the engine to be lifted out a bit. Coolant was weeping out of two. An otherwise fine block was compromised by these weak points that eventually corrode. That must be the reason the 3800 V6 specified a certain type of coolant.

So I am not the only tech that have come across some idiot's use of RTV on a head gasket.

From the last image it appear to one of the Intek cross flow heads and yes they are bad about blowing the cylinder and push galley. Don't forget to check for cylinder head warpage.

Hi AVB,
Yes it is an Intek motor and it does have slight warpage on the head in the tunnel section as well as the same warpage on the barrel in the same area. It is only minimal with the light behind the straight edge but it is visible. They needed another headbolt in that area
Had a call from the current owner last night and he had been in contact with the person he had bought it off and he had no knowledge of the motor being rebuilt. This is sounding like he had bought it from somebody who had rebuilt the motor, couldn't get it running right, flipped it , then the next bloke couldn't fix it so flipped it again to my mate. Always suspect when people are not straightforward with info on these things, the old Shultz thing, "I know nothing"

Head gasket arrived and I fitted that today and it pumps up a massive 40 psi so that was a big waste of time and effort, now to do what I should have done in the first place, dump the Briggs and put a new Chonda on it.
Now my next question is seeing this has a brand new starter, can I fit this to the 10.5 motor sitting here on my mates Deutscher. I'm guessing no one would know, I guess I will have to start taking some measurements to see what the differences are with the flywheels

What sort of 10.5hp Norm? I think at the very least you would have to change the starter drive cog, but knowing briggs they probably have done something to stuff up an easy changeover

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Hi Tyler,
Well I now have this 14.5 OHV here that is scrap and the Deutscher is a 10.5 OHV Couldn't be lucky enough to be able to swap the bits across

Sorry not coming back sooner. I had yet another battle with my Afib. It is something new for me to learn how to deal with. Got it quickly this time but the PD this tanked to 70/30. Getting back to close to normal again.

As for the Inteks in general yes they should re-engineer these engines and add a bolt(screw) to the web area between the cylinder and push rod galley. I haven't lost any engines yet back I have shaved a few heads. Not seen the crankcase warpage yet and hope not to.

I believe the 10.5 OHV would be close to a 21 Cu In then the 28 Cu In the 14.5 is.

Thanks AVB,
Hope you are feeling a bit better and getting back to normal.
When I sent my mate a pick of the pressure gauge sitting on 40 psi I got a reply from him "oh dear" and haven't heard from him since so I will just push it further back in the shed.