Home / Engine hours

Engine hours tampered with? How to check before you buy a used boat

On a used boat the engine hour meter plays the role of a car's odometer: it hints at wear and value. Unlike a car, though, the meter is often a simple gauge in the dashboard that can be replaced, disconnected or reset. A low reading on its own proves very little. This guide shows the checks to make before you buy, the signs that hours have been tampered with or wound back, and how to protect yourself in the contract.

There is a checklist to take to the viewing at the end. Our used boat checklist covers the rest of the boat.

Why the hour meter alone is not enough

A conventional hour meter counts while it has power or while the engine runs. If it has been replaced, was faulty for a while or the engine ran with the plug pulled, the reading no longer matches the engine, with or without bad intent. On twin engine boats, or where a newer engine sits in an older boat, the meter and the engine may not even belong together.

So always ask the seller: is this the original meter? Has the engine, the dashboard or the control unit ever been replaced? Get the answer in writing; a message is fine.

Does the wear match the hours?

An engine with few hours looks different from one that has done many seasons. Watch for things that do not fit a low reading:

polished throttle levers, ignition key, wheel and a worn helm seat on a boat said to have been little used,
salt deposits, corrosion and faded paint on the engine or outboard cowling,
play and wear in the propeller, drive and steering,
oil leaks, discoloured coolant or heavy smoke on a cold start,
service stickers in the engine bay with dates and hours that do not match the meter.

One sign alone proves nothing. If several do not fit, look hard at the paperwork and bring in a surveyor.

Line up the service records

Workshops usually write the engine hours on the invoice or in the service book. Put all records in date order. The hours must go up over time. If they drop between two invoices, if years are missing, or if today's reading is lower than the last invoice, ask why.

If in doubt, call the workshop named on the invoice and ask whether the record is theirs. They may need the seller's consent to tell you anything, so ask the seller for it.

What the engine control unit stores

Many modern fuel injected engines have an electronic control unit that records running time, and some also log how long the engine spent in each rev range. Authorised dealers of the brand can read this with the manufacturer's diagnostic software. Whether that works for a particular engine is something the brand's dealer can tell you, so ask before the viewing and agree with the seller who pays.

Compare the stored figure with the meter and with the invoices, keep the printout and attach it to the contract. Older carburettor engines have no such memory; there you rely on wear, records and a workshop check such as a compression test.

What the sale contract should say

Do not just write the hours down; ask the seller to warrant them. Private sales are often made without any liability for defects, but in many countries an express promise about a specific feature, or deliberately hiding a defect, is not covered by such a clause. The contract should include:

the engine with make, model, serial number and year,
the hours shown on the meter and, if read out, in the control unit,
a sentence in which the seller warrants that the engine has run no more than the stated hours and that he knows of no tampering with the meter,
whether the meter, dashboard or engine has ever been replaced,
the list of service records handed over.

A printable boat sale contract is on our site; add the sentence about the hours.

Survey and sea trial

On an expensive boat a pre purchase survey of hull and engine is money well spent. A surveyor spots wear that buyers miss and can arrange an oil analysis, a compression test and the electronic read out. For the sea trial, ask for the engine to be cold when you arrive and watch it start. Under load, keep an eye on temperature, smoke and noise.

Many hull and machinery policies only pay for engine damage if the engine was serviced as the maker requires, so complete service records matter again later. Check the engine section of your own policy.

If you become suspicious after the sale

If you only find out after buying that the hours cannot be right, secure everything first: contract, a screenshot of the advert, photos of the meter, the read out, invoices and messages with the seller. Have a qualified workshop confirm the findings in writing and take legal advice before you confront the seller. Deliberately winding back hours to get a higher price can be a criminal offence in many countries.