1970 volvo 170 won't rev up witth load

redfred60

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Joined
Dec 16, 2010
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Just bought a 1970 boat w/170 hp motor. The motor starts and idles fine but won't get over 2200rpms. Replaced fuel pump but that didn' do it. Any suggestions where to start looking from here??
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
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Re: 1970 volvo 170 won't rev up witth load

List of possible causes of low WOT (Wide Open Throttle) rpm.

In no particular order

Engine Won't Reach Operating RPM. Check

1. Fuel condition. Type and Octane possibly old fuel
2. Propeller pitch or diameter, damaged blades
3. Restricted fuel pickup tube or anti siphon valve Fuel System Test
4. Crankcase oil volume, high oil level can cause aerated oil and lifter collapse
5. Marine growth on hull and outdrive
6. Wrong gear ratio in outdrive
7. Restricted carburetor air intake (clogged flame arrestor)
8. Restricted exhaust system (broken exhaust shutters/flappers) in engine transom shield or drive
9. Poor cylinder compression Compression Test
10. Carburetor defective, or wrong type.
11. Fuel pump pressure and vacuum
12. Boat overloaded, improperly loaded, or improperly trimmed.
13. Engine Overheating
14. Engine timing and ignition system operation
15. Remote control cables and linkage for proper travel to open throttle plates fully.
 
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