QuestionQUESTION: A week or so ago you suggested I put a finger over the spark plug hole and pull the starter to check the compression. I did this and there was no pressure at all.
The engine is completely drained of oil. Would that affect the compression? Should there be oil in the engine when checking compression?
Thanks.
ANSWER: Crankcase oil in the engine has very little impact on compression. With or without oil the compression should "pop" you thumb off the spark plug hole.
No compression indicates a broke rod, severly blown head gasket, stuck valve or hole in the top of the piston.
Refresh my memory, is this the old snowblower engine that sat for many years?
Eric
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QUESTION: Yes, it came off my father's snowblower. It was running great, then 5 or 6 years ago it stopped and the starter couldn't be pulled. The oil looked low so he thought the engine had seized up and was no longer any good.
He took it off and put on a used replacement enhine. The "seized" engine was under his porch covered with a tarp for several years. This year I tugged on the starter and was surprised it pulled out and retracted ok. I moved it to my cellar and that's where it is now.
As I mentioned before, I can clearly see one valve moving up and down through the plug hole. Should both valves be visable through the plug hole?
If I decide to replace the engine with a new one, is there a way to know which new engine I should use by checking the model number of the old engine?
Also, is there a way to determine h.p from the model number? I have an older B&S manual, about 25 years old that explains how to interpret the model number, but nothing is mentioned about h.p.
ANSWER: HP is not the best method to determine engine size. If you look at the first 2 digits of the Briggs model number this is the cubic inch. 13 is typically a 5 hp in L head engine, 25 is about 11 hp...
Send me the Briggs model, type and code number and I can let you know about what hp it is.
It is difficult to see both valves through the spark plug hole. From where you are at today, I would recommend pulling the head and inspecting the cylinder/valves. On older engines you can re-use the head gasket but Briggs does not recommend it.
Remove the cylinder head and see if the piston moves up and down when you pulle the string. Pay attention to the head bolts...longest head bolts should be on the exhaust side.
Let me know the engine numbers and what you find when you remove the cylinder head.
Eric
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QUESTION: Engine # is 170402 0714-01 7006251. If I replace this engine with a new one, what displacement, h.p., etc. should I look for?
Took the head off and both valves were ok, but the piston didn't move. I pushed down on it a bit and it went down and stayed there. Now the engine is seized up.
Guess this means the connecting rod is broken, right?
If I decide to replace that, is it a difficult job? Which part should I open to see the bottom of the connecting rod?
AnswerThe engine is roughly an old 1970 7 hp engine. I'd consider replacing with 9 hp Intek.
As for the connecting rod, remove the rear engine sump. Before removing, use some sandpaper and sand the shaft smooth to make removing the cover eaiser.
When removing the sump cover, make sure the starter is facing down on the work bench to keep the cam and valve tappets from falling out.
Make sure you note the timing marks and mark the tappets intake and exhaust.
Eric
