RichardInDorset
Member
I have recently got hold of a 1980's 9.8hp, in very nice condition. It starts fine, runs fine but out on the water it will only make about 5-8knots on my 3.6m inflatable - it actually performs slightly worse than my 2.5hp 4 stroke!
It looks like it has never been dismantled as the bolts on the engine block are all still painted.
One thing I did notice was that the air intake guard is missing from the carb. When you prime the fuel, if you squeeze the primer bulb hard, fuel comes out of a hole near the intake guard mounting bolt holes.
On the parts diagrams this hole appears to have a plug (part number 16), so might this be a cause of low power?
I'm not sure if the plug is missing or if it is there and the fuel is leaking past it...
There's no fuel leak when running.
The throttle opens fully. The plugs are new.
I will check crankcase compression and take a look under the cover over the reeds/ports.
Anything else to check before I go further and start stripping it down?
It looks like it has never been dismantled as the bolts on the engine block are all still painted.
One thing I did notice was that the air intake guard is missing from the carb. When you prime the fuel, if you squeeze the primer bulb hard, fuel comes out of a hole near the intake guard mounting bolt holes.
On the parts diagrams this hole appears to have a plug (part number 16), so might this be a cause of low power?
I'm not sure if the plug is missing or if it is there and the fuel is leaking past it...
There's no fuel leak when running.
The throttle opens fully. The plugs are new.
I will check crankcase compression and take a look under the cover over the reeds/ports.
Anything else to check before I go further and start stripping it down?