OS FS.70 Surpass . Valve cleaning/laping advice?
01-22-2023, 05:57 PM
#26
My Feedback: (1)
Hi all,
Thanks for all advice. I got hold of some very fine honing compound. Seems a tad more course than the metal polish compound I have but finer than the valve lapping compound. I dismantled and gave it a try. Only did a gentle round with the valves. Put things together and exactly the same leak. Started the engine in a bench tester. Had to use the starter, no luck flipping it to start by hand. Did not get it to run reliable. It did 10500RPM with a 12x7 APC on it.
Back to square one. I will just throw it back into the box at the moment, using it for future spares to my #1. Maybe I will decide on a new try after some thinking...
Thanks for all advice. I got hold of some very fine honing compound. Seems a tad more course than the metal polish compound I have but finer than the valve lapping compound. I dismantled and gave it a try. Only did a gentle round with the valves. Put things together and exactly the same leak. Started the engine in a bench tester. Had to use the starter, no luck flipping it to start by hand. Did not get it to run reliable. It did 10500RPM with a 12x7 APC on it.
Back to square one. I will just throw it back into the box at the moment, using it for future spares to my #1. Maybe I will decide on a new try after some thinking...
Jim
Last edited by the Wasp; 01-22-2023 at 05:59 PM.
01-22-2023, 10:30 PM
#27
Hi,
New valves might be an option. Trying to find replacements, but this is an old engine. I have found valves for the FS70SII, but not the first one. They might be the same but the part list in my manual only shows part no for the "valve assembly" which not match. Its the same valves for the FS70SI as for the FS91SI
Manual shows:
45960000 - Intake valve assembly
45960010 - Exhaust valve assembly
Can not find these available. on the other hand, I can find available:
45960100 - Intake valve for OS FS70/90SII
45960110 - Exhaust valve for OS FS70/90SII
It might be the same for the SI , but need to get this verified. Anyone knows?
New valves might be an option. Trying to find replacements, but this is an old engine. I have found valves for the FS70SII, but not the first one. They might be the same but the part list in my manual only shows part no for the "valve assembly" which not match. Its the same valves for the FS70SI as for the FS91SI
Manual shows:
45960000 - Intake valve assembly
45960010 - Exhaust valve assembly
Can not find these available. on the other hand, I can find available:
45960100 - Intake valve for OS FS70/90SII
45960110 - Exhaust valve for OS FS70/90SII
It might be the same for the SI , but need to get this verified. Anyone knows?
Last edited by MrRover75; 01-22-2023 at 10:38 PM.
01-22-2023, 11:08 PM
#28
At some point one has to consider the cost to repair vs replacement cost. It may not even be possible to find new or used serviceable parts. I have a grand box of used engines and parts. My freinds and club members are welcome to scavenge and a few have been able to resurrect some motors.
01-22-2023, 11:55 PM
#29
At some point one has to consider the cost to repair vs replacement cost. It may not even be possible to find new or used serviceable parts. I have a grand box of used engines and parts. My freinds and club members are welcome to scavenge and a few have been able to resurrect some motors.
01-23-2023, 02:20 AM
#30
Hi,
New valves might be an option. Trying to find replacements, but this is an old engine. I have found valves for the FS70SII, but not the first one. They might be the same but the part list in my manual only shows part no for the "valve assembly" which not match. Its the same valves for the FS70SI as for the FS91SI
Manual shows:
45960000 - Intake valve assembly
45960010 - Exhaust valve assembly
Can not find these available. on the other hand, I can find available:
45960100 - Intake valve for OS FS70/90SII
45960110 - Exhaust valve for OS FS70/90SII
It might be the same for the SI , but need to get this verified. Anyone knows?
New valves might be an option. Trying to find replacements, but this is an old engine. I have found valves for the FS70SII, but not the first one. They might be the same but the part list in my manual only shows part no for the "valve assembly" which not match. Its the same valves for the FS70SI as for the FS91SI
Manual shows:
45960000 - Intake valve assembly
45960010 - Exhaust valve assembly
Can not find these available. on the other hand, I can find available:
45960100 - Intake valve for OS FS70/90SII
45960110 - Exhaust valve for OS FS70/90SII
It might be the same for the SI , but need to get this verified. Anyone knows?
Not sure about the intake...
Last edited by MrRover75; 01-23-2023 at 02:24 AM.
01-29-2023, 02:37 AM
#31
Got hold of an used FS@81 for a reasonable price. This one should be good according to the seller and has just done a gallon of fuel through it. Crossing fingers for that this is a good one. Will probably receive it this week. The #2 FS70 will be put back in the box for spares for now....
