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Sudden start problem
- Thread starter motomike
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- Sep 7, 2024
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Hi motormike,
The reason for the air shrouds is to concentrate air around and through the cooling fins of the cylinder(s). The flywheel air fins and top cover are what force the air past the cylinder(s). Without them they would allow overheating and eventually the motor will become physically damaged internally.
The reason for the air shrouds is to concentrate air around and through the cooling fins of the cylinder(s). The flywheel air fins and top cover are what force the air past the cylinder(s). Without them they would allow overheating and eventually the motor will become physically damaged internally.
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I tried to reply to the no compression issue on one cylinder earlier, but my reply disappeared somewhere.
Anyway, the engine likely bent a pushrod due to an overheat or lack of proper adjustment. No compression means an intake valve is not opening on that cylinder.
Be aware that valve guides will also slip up out of place in the head and the rocker will collide with the valve retainer and spring assembly. That will also bend a pushrod.
If the guide has moved up out of the head, the head should be replaced. Driving the valve guide back down will not fix the real problem. The machined press-fit tolerance that holds the guide in place has been compromised.
Anyway, the engine likely bent a pushrod due to an overheat or lack of proper adjustment. No compression means an intake valve is not opening on that cylinder.
Be aware that valve guides will also slip up out of place in the head and the rocker will collide with the valve retainer and spring assembly. That will also bend a pushrod.
If the guide has moved up out of the head, the head should be replaced. Driving the valve guide back down will not fix the real problem. The machined press-fit tolerance that holds the guide in place has been compromised.
Auto Doc, this is a flat head engine, it has "pushrods?"
I'm going to pull the head cover and look for a blown head gasket. Clean up the carbon, put a straight edge across block and cover.
There are 9 head bolts, I assume they're reusable? Do they usually come out without issue? Then I'm thinking I can turn over engine with the starter and watch the valves to see if there's any issue with their operation?
I'm going to pull the head cover and look for a blown head gasket. Clean up the carbon, put a straight edge across block and cover.
There are 9 head bolts, I assume they're reusable? Do they usually come out without issue? Then I'm thinking I can turn over engine with the starter and watch the valves to see if there's any issue with their operation?
Well due for maintenance. Check your engine manual for proper instruction.Decided to grease the spindles on my '99 Murray with the 17hp BS Twin
1.De-carbon the cylinders.
2.Lap some valves.
3.Check valve clearance.
4. Pull fuel line AT the carb inlet. Drain into a glass jar. Watch for a solid fuel flow. Look for water in the bottom of the jar.
5.Make sure both cylinders are contributing.
6.Clean cooling fins.
Riiiiight.....Cleaned tank,
Fuel lines from 1999 are due for replacement. Lines actually fail internally where you can't see anything.blew out fuel lines to carb
Need to verify good flow of fuel into carb. Also pull the oil stick and smell for fuel as another person suggested. Crack open the fuel tank cap and see what you get.new fuel filter, fresh gas. Still won't run. Got a pair of new plugs and it tried to run a little better but still no go.
An 8 year old carb probably 12 years old is due for a cleaning. Think you could have a ton of trash in the tank outlet, that you can't see.Looking down the throat of the carb, it looked super clean. It's a replacement carb I installed 8 yrs ago,
What do you think this means? Not getting enough........The plugs were dry when I removed them
Chickanic I think it was found bad fuel in those premixed cans that cost a fortune. Think she said don't buy that junk. It was stale and full of water.Buying pre-mix 'fuel' is like buying water. Why? Why pay $20/gallon when you can buy ethanol-free gas for $4/gallon and mix in a $2 bottle of 2-cycle oil? I saw a 2-gallon can of a popular brand of pre-mix gas at Walmart a few days ago for almost $40. That would last me about a week as much as I go through. Not even close to practical. In my opinion, of course.
Also think it was Taryl who found out alcohol doesn't absorb water and pass out of the engine via burning. Best to drain any suspect fuel and pour in fresh E-0 gas.
1.Are the valves closing proper?Back to the Murray problem, I did a compression test today. Cylinder 1(left) 0 psi, cyl. 2(right) 110 psi. Suggestions?
2.Do the valves seal proper?
3.Your test equipment working proper? Possible bad O-ring on the hose. Hose not tight enough?
4.Overheated and valve guide move from proper resting location?
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Hello motormike,Auto Doc, this is a flat head engine, it has "pushrods?"
I'm going to pull the head cover and look for a blown head gasket. Clean up the carbon, put a straight edge across block and cover.
There are 9 head bolts, I assume they're reusable? Do they usually come out without issue? Then I'm thinking I can turn over engine with the starter and watch the valves to see if there's any issue with their operation?
I apologize, I lost track of out earlier conversation, and this site has delay issues that creates frustration and confusion. Being an opposed twin engine, pull the heads and watch the valve and piston movement to make sure they are working.
It been a few years since I have worked on those on a regular basis, but they were long lasting reliable engines.
The head bolts are reuseable but keep them in order of location. (A cardboard template works well for this).
It would not hurt to actually break them free by trying to tighten (tweak) them very slightly before removal. This usually eliminates rust frozen bolt thread problems.