If your jet ski has not been running so smoothly or it’s having trouble starting up, then our certified Yamaha dealers and mechanics can sort you out. We run jet ski diagnostics to determine the issue with your personal watercraft and repair or replace parts for an efficient engine, smooth ride and improved steering. At NWS Marine, we will see your watercraft in our workshop in Wolverhampton and offer competitive, transparent pricing for repairs and improvements.
If your jet ski diagnostics reveal you need new parts, we have a large stock of Yamaha parts, but we can also quickly order replacements for other makes and models. We offer performance packages to improve the performance and speed of your Yamaha WaveRunners, so if this is something you’re interested in, we can get this sorted at the same time.
Below are some common issues riders might experience with their PWC, however, our jet ski diagnostics can determine other problems or faults such as sensor and safety system faults, or issues after pulling it out of storage.
Engine & Starting Issues
Symptoms: Won’t start, hard starting, stalls, rough idle
Common causes:
- Weak or dead battery
- Fouled or worn spark plugs
- Bad ignition coils or plug wires
- Fuel injector clogging (especially after storage)
- Faulty crankshaft position sensor
- Low compression (worn rings or valves)
Diagnostics:
- Battery load test
- Spark test at each cylinder
- Compression test
Fuel System Problems
Symptoms: Hesitation, bogging, poor acceleration
Common causes:
- Old or contaminated fuel
- Clogged fuel filter or water separator
- Failing fuel pump
- Malfunctioning fuel pressure regulator
- Air leaks in fuel lines
Diagnostics:
- Fuel pressure test
- Injector resistance test
- Visual inspection for leaks or cracked hoses.
Cooling System Issues
Symptoms: Overheating, limp mode, warning alarms
Common causes:
- Clogged cooling lines (sand, weeds, shells)
- Stuck thermostat
A damaged wear ring reduces water flow
Riding in shallow or debris-filled water
Diagnostics:
- Flush the system and inspect the water flow
- Check thermostat operation
Inspect the intake grate and pump tunnel
Electrical & ECU Faults
Symptoms: Warning lights, error codes, intermittent shutdowns
Common causes:
- Corroded connectors (very common in saltwater)
- Faulty sensors (temp, MAP, TPS, oxygen)
- Bad grounds
- ECU communication issues
Diagnostics:
- ECU scan tool for fault codes
Voltage drop testing - Continuity and resistance checks
NWS Marine have been in the jet ski and watercraft business for more than twenty years and as watercraft specialists, we have the knowledge and expertise for modifying, advising and servicing your waverunners so they perform their best on the water. Our attention to detail means we quickly identify your issues and come up with a solution- for a great price! We try our best to complete the repairs as soon as possible for your convenience and keep you updated with its condition, the same you’d expect when you take your car into the garage.
We supply a range of jet ski accessories to ensure safety and comfort on the water. From wetsuits, life jackets, and trailers for travelling with your ski, we supply an all-round service. We are partnered with many brands and we stock a range of quality parts, equipment so you can immerse yourself in your jet ski experience.
Midlands Yamaha Waverunner & Outboard Main Dealer
Contact Us
Unit B5, Hilton Main Ind. Est.
Bognop Road
Wolverhampton
West Midlands
WV11 2BE
t: 01902730717