Why generators show "engine cranks too stiffly": 12 documented causes and brand-specific fixes, compiled across 7 manufacturers.
Too heavy oil in crankcase
3 brands- Cummins/Onan: Drain and refill with lighter oil; Drain, refill with lighter oil
- Doosan: Drain, refill with lighter oil
- generatorpartspro: Drain and refill with lighter oil
Too heavy oil in crankcase.
2 brands- Cummins/Onan: Drain, refill with lighter; Drain, refill with lighter oil.
- Mcck: Drain and fill with lighter oil.
Too heavy oil in crankcase, Engine stuck.
2 brands- Cummins/Onan: Drain. Refill with light oil, See PREPARATION, Disassemble and repair.
- Onan Electric: Drain. Refill with light oil, See PREPARATION, Disassemble and repair.
Too heavy oil in crankcase. Engine stuck.
2 brands- Cummins/Onan: Drain. Refill with light oil. Disassemble and repaiz.
- Prestolite: Drain. Refill with light oil. Disassemble and repaiz.
Load not disconnected from unit. Too heavy oil in crankcase. Engine stuck. Compression release in running position. NOTE: Engine may not even turn over.
1 brand- Cummins/Onan: Disconnect load from unit when starting. Use only recommended grades. Disassemble and repair. Compression release must be at start position when starting the engine.
Corroded terminals, Too heavy oil in crankcase, Weak battery
1 brand- Cummins/Onan: Clean and tighten terminals, Drain, refill with light oil, Test and recharge or replace battery
[oil in crankcase too heavy for low temperature. Load connected. Defective decompression release. Worn or damaged fuel transfer pump. Air leak in fuel lines. Clogged fuel lines. Fuel tank too far below engine.
1 brand- Cummins/Onan: Check oil specification, change oil if necessary. Disconnect load. Check and adjust decompression release. Replace or rebuild pump. Tighten all corrections, check for defects in lines. Clean fuel lines. Ensure fuel tank is no more than 6 ft. below engine.
Too heavy oil in crankcase Engine seized Load connected Decompression release (on 1 cylinder diesel) at running position
1 brand- Cummins/Onan: Drain, refill with light oil Dis-assemble and repair Disconnect Place at start position
Congealed lubricating oil, Engine stuck
1 brand- Cummins/Onan: Change to recommended oil., Disassemble and repair.
Too heavy oil in crank-case.
1 brand- Cummins/Onan: Drain. Refill with lighter oil. Disassemble and repair.
Too heavy oil in crankcase, Drain. Refill-with lighter oil. See PREPARATION.
1 brand- Cummins/Onan: Drain. Refill-with lighter oil. Disassemble and repair.
Too beavy oil in crankcase.
1 brand- Cummins/Onan: Drain, refill with lighter oil.