Powersports - Yamaha Waverunner VX1100

Yamaha Waverunner won't start or stalls

A Yamaha VX1100 Waverunner stalled on the water and would not restart. What followed was five separate issues diagnosed and resolved over one season, documented here in the order they were found. Covers a disconnected exhaust pipe, oil overfill, wrong battery, failed rectifier/regulator, and water in the fuel. Also includes the full error code list, correct battery and spark plug specs, and the oil level procedure specific to this engine.

Overview: the initial stall was caused by a disconnected rubber exhaust pipe that looked attached. Subsequent warning lights and codes led to discovering oil overfill, a wrong battery, and eventually a failed rectifier/regulator. Water in the fuel caused a later sputtering episode. Each issue is documented below with cause, fix, and relevant notes.

Issue 1 - Disconnected exhaust pipe

Cause The rubber exhaust pipe inside the hull had disconnected from its fitting. It looked attached but was not seated. The engine was being starved of airflow, which caused stalling and prevented restart.

Fix Reconnected the pipe. Engine ran normally immediately afterward.

Smoke inside the hull is not normal. There should never be smoke accumulating in the engine compartment during normal operation. If smoke is visible when the seat is removed, treat it as a sign something is disconnected or burning rather than assuming it will clear once the engine runs.

Smoke inside Yamaha Waverunner hull from disconnected exhaust pipe — Smoke from the hull - caused by the disconnected exhaust pipe, not a fire

Issue 2 - Oil overfill causing fouled plugs and clogged air filter

Cause The oil level was checked when the engine was cold and filled to the midpoint between empty and full. On the VX1100, checking oil cold gives an inaccurate low reading. Filling to what appears to be correct when cold results in overfilling once the engine warms and oil redistributes. Excess oil pushed through the breather into the air filter box, saturating the air filter with oil.

Fix Run the engine hard for at least 20 minutes before checking the oil level. The correct approach on this engine is to start with a nearly empty level and add oil conservatively rather than filling to the midpoint cold. Clean or replace the air filter if oil saturation is found.

The air filter at the Yamaha dealer was $120. The same filter was found online for $80. The dealer confirmed the filter can be cleaned with an appropriate filter cleaning solution and re-oiled with filter oil rather than replaced immediately.

Yamaha Waverunner air filter saturated with oil from overfilling — Air filter saturated with oil from overfilling when cold

Issue 3 - Wrong battery type causing Code 19 voltage warnings

Cause A standard automotive battery (EverStart 16CL-B from Walmart) was used as a replacement. Standard batteries are not designed for the vibration and impact loading of PWC use. The severe wave impacts and hull vibration destroy the internal plates of a standard battery quickly. The result was fluctuating voltage between 11.5 and 12.4 volts, triggering Code 19 (incorrect battery voltage) at 11.5 volts.

Fix Replace with an AGM (absorbed glass mat) battery designed for marine and PWC use. The Odyssey PC625 is specifically recommended for Yamaha VX-series Waverunners and handles vibration without internal plate damage. Cost was $98-101 with free shipping from battery specialty retailers.

A standard battery may pass a basic voltage test at 12.2V when sitting but fail under load. Load test the battery rather than just measuring static voltage if you suspect battery problems.

EverStart standard automotive battery - wrong type for Yamaha Waverunner use — Standard automotive battery - not suitable for PWC vibration

Odyssey PC625 AGM battery - correct battery for Yamaha Waverunner VX1100 — Odyssey PC625 - AGM battery designed for marine/PWC use

Issue 4 - Failed rectifier/regulator

Cause After replacing the battery, Code 19 persisted. The voltage would start at 12.2V cold, climb to 13.0V, then drop rapidly back to 12.1V as the machine warmed up. Visual inspection revealed heat damage and visible cracking on the rectifier/regulator housing. Running at full speed for 3 minutes made the unit extremely hot to the touch. A functioning rectifier should hold voltage at 14.5 to 14.7V under load.

Fix Replace the rectifier/regulator assembly. After replacement, voltage held at 14.5 to 14.7V throughout a full run and did not drop. Part number: 6D3-81960-00-00 RECTIFIER and REGULATOR ASSY, VX1100BH. Cost approximately $105.

The rectifier/regulator is easy to locate and remove for inspection. If the unit is hot to the touch after a short run, shows any cracking or discoloration of the housing, or if voltage drops under load rather than holding steady above 14V, the unit needs replacement.

Location of rectifier/regulator on Yamaha Waverunner VX1100 — Rectifier/regulator location on the VX1100

Yamaha VX1100 voltage regulator close up — Voltage regulator close-up

Heat damage visible on Yamaha Waverunner voltage regulator housing — Heat damage on the regulator housing

Cracks in Yamaha VX1100 voltage rectifier from heat damage — Cracking from heat damage - confirmed the unit had failed

Yamaha VX1100 voltage rectifier connector locations — Rectifier connector locations for removal

Part number: 6D3-81960-00-00 RECTIFIER and REGULATOR ASSY VX1100BH, approximately $105

Issue 5 - Water in the fuel

Cause Small amounts of water accumulated in the fuel, causing sputtering as if the engine was starved. Plugs appeared fouled but replacing them did not resolve the problem.

Fix Add 98% or higher isopropyl alcohol to the fuel at approximately 1 oz per gallon. Isopropyl alcohol absorbs water from the fuel because it is missing a water molecule - when mixed with water-contaminated gasoline, it pulls the water into solution and allows it to pass through the engine harmlessly. Common brand name: Iso-Heet. A 32 oz can of Klean-Strip denatured alcohol (90-100%) from hardware stores also works at a similar ratio.

Do not use standard rubbing alcohol (70% isopropyl). It already contains water and will not help. Do not use products based on methanol or methyl alcohol - these can deteriorate O-rings and fuel lines. Only 98%+ isopropyl alcohol is appropriate.

How to read Yamaha Waverunner error codes

With the engine running, hold the MPH/VOLT button for 8 seconds. On some models this is labeled the alarm cancel button. The display will show a numeric code. Code 01 means normal operation.

Yamaha Waverunner display showing error code 19 - incorrect battery voltage

Display showing Code 19 - incorrect battery voltage warning

Code	Description
`01`	Normal operation
`13`	Pickup coil malfunction
`15`	Engine temperature malfunction
`19`	Incorrect battery voltage
`23`	Intake air temperature malfunction
`24`	Cam position sensor malfunction
`29`	Intake air pressure malfunction
`47`	Slant detection switch malfunction
`48`	Incorrect data transmission
`55`	Steering switch malfunction
`112-123`	Electronic control throttle system malfunction
`124-128`	Throttle position sensor malfunction
`129`	Electronic control throttle system malfunction
`131-135`	Accelerator position sensor malfunction
`136-139`	Electronic control throttle system malfunction
`141-145`	Electronic control throttle system malfunction

If your code is not in the list above, a Yamaha Diagnostic System (YDS) is required to read it. These are available on eBay for around $125.

Yamaha VX1100 reference specs

Verified specs for the VX1100 Deluxe. Useful for ordering parts and setting correct service intervals.

Spark plug (current)	NGK 6955 (as of 2022 - replaces CR9EB)
Spark plug gap	0.7 - 0.8 mm (0.028 - 0.031 in)
Plug cross references	CR9EB, CR9EIX, C9E, CR9E, CR9EVX
Recommended oil	SAE 10W-30, 20W-40, or 20W-50 - API SE/SF/SG/SH/SJ/SL
Oil with filter replacement	2.2 L (2.33 US qt)
Oil without filter replacement	2.0 L (2.11 US qt)
Oil total capacity	4.3 L (4.55 US qt)
Fuel	Regular unleaded
Fuel tank capacity	60 L (15.9 US gal)
Engine	Liquid cooled 4-stroke DOHC, 4 cylinders, 1052 cc
Maximum load	240 kg (530 lb), 3 persons
Trolling speed	1,650 rpm +/- 50

Reader reports

2013 VX1100 - immediate overheat on first run after winter

Alarm came on almost immediately after launching with a new battery installed. Overheating confirmed - no cooling water was getting through the system. Flushed the intake to clear any debris. Ran normally for 5 minutes then overheated again. This pattern points to a blockage in the cooling water intake or a failed impeller allowing water to bypass the cooling circuit. Checking the intake grate and impeller for obstruction is the first step before assuming a thermostat or pump fault.

Flooded engine from flushing procedure

A 2013 FZS SHO was started for its first flush of the season. The flush hose was turned on before the engine was started. The engine ran rough and was shut off with the water still flowing. Result: flooded engine that would not run normally for days. The correct procedure is engine on first, then water on. If the engine stops for any reason while flushing, shut the water off immediately.

Air filter check as quick diagnostic

If warning lights are on and the engine is running rough or not revving correctly, check the air filter before anything else. To quickly test whether the filter is the issue, remove it and run the engine briefly without it. If performance improves, replace the filter. Note: the VX-series air filter is not interchangeable with standard filters.

Questions that come up most

How do I read the error code on a Yamaha Waverunner?

With the engine running, hold the MPH/VOLT button (or the alarm cancel button on some models) for 8 seconds. The display will show a numeric code. Code 01 means normal operation. Cross-reference your code against the table on this page. If your code is not listed, a Yamaha Diagnostic System (YDS) tool is needed - available on eBay for around $125.

The green security light is on when the ski is not running. Is this a problem?

No. The green security light being illuminated when the engine is off is normal on the VX1100.

What is the correct battery for a Yamaha VX1100?

An AGM (absorbed glass mat) battery designed for marine or PWC use. The Odyssey PC625 is a documented fit for the VX-series. Standard automotive batteries fail quickly due to the vibration and impact loading from waves. A standard battery may test at acceptable voltage when static but fail under load.

How do I check the oil level correctly?

Run the engine hard for at least 20 minutes before checking the oil level. Checking cold gives an artificially low reading and leads to overfilling. When doing an oil change, note that only about half the oil drains out - refill only the drained amount plus whatever was actually low, not a full refill to the top mark.

How do I flush the engine correctly without flooding it?

Start the engine first, then turn on the flush hose water. Never turn water on before the engine is running. If the engine stops while water is still flowing, shut the water off immediately. Water flowing into a stopped engine can flood and hydrolock the cylinders.

What should I do if I see smoke coming from the hull?

Smoke inside the engine compartment is not normal. It indicates something is disconnected, overheating, or burning. Remove the seat and inspect the exhaust pipe connections before running the engine again. A disconnected exhaust pipe looks attached but will cause the engine to stall from oxygen starvation and fill the hull with exhaust smoke.

I have Code 19 and a new battery. What else could cause it?

Code 19 indicates incorrect battery voltage. If a new correct battery still triggers the code, test the rectifier/regulator. Check voltage at idle and under load - a healthy system should hold 14.5 to 14.7V. If voltage drops under load or the rectifier housing shows cracking or heat damage, the unit needs replacement. Part number: 6D3-81960-00-00.

Code 123 appeared after winter storage. What does it mean?

Code 123 falls in the 112-123 range indicating an electronic control throttle system malfunction. This has been reported on several models coming out of winter storage. Check for moisture in electrical connections, the throttle body, and any connectors that may have corroded over winter. If the ski runs normally otherwise, clearing the code and testing on the water may resolve it if a sensor triggered from cold or condensation.

Related Waverunner guides:

This documents a series of repairs on a specific 2008 Yamaha VX1100 Deluxe. Part numbers and procedures may vary by model and year. Verify specs against your model documentation before ordering parts. Any work involving electrical systems or fuel should be done in a well-ventilated area with the battery disconnected where appropriate.