F100 Yamaha Age/Identification with serial number label painted over!

Twostrokefan

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Sep 28, 2011
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Hello and I'm hoping someone on this amazing forum can help me help a friend. He has an F100 for quite a few years and I asked him recently when he'd last got it a Timing Belt. Never was the answer and he'd bought it at an auction about 5 years ago with a fresh service but no history. When I looked at it to check the date codes I found the transom bracket had been completely repainted previously due to a leak of ATF fluid from the hydraulic steering. So the Yamaha factory serial label has been obliterated.:facepalm: Also the date code label on the other side of the bracket is either gone or buried under paint. He says the serial number is Three One Seven Five Six Two from his insurance documentation. That reads like it's in the correct range but doesn't include any date code letters so I can't tell how old the engine is.

Can anyone please advise where else the engine number can be found e.g. stamped into the block and whether there's any way to tell the year of manufacture which may well be how old the Timing Belt is on this engine.

Many thanks for your help!
 

Twostrokefan

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Re: F100 Yamaha Age/Identification with serial number label painted over!

Hi Guys, just bumping this one after the helpful Yamaha dealer was unable to help. He says he knows of no other place to find the engine serial number other than the Transom Bracket. That seems surprising becasue it would mean simply changing the transom bracket (or painting over it) would obliterate any traceability on a stolen engine.
The main reason is to find out when if ever it had a Timing belt fitted but if in doubt it seems wise to get one fitted now. However it would also be important should the boat ever be offered for sale.
So please, if anyone can tell where else the engine serial number can be found I'd be grateful.

Thank you for any suggestions
 

Ldavidgrover

Petty Officer 2nd Class
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Feb 22, 2012
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197
Re: F100 Yamaha Age/Identification with serial number label painted over!

Since you out of the US. Is you F100 Carb or Fuel injection?
 

Twostrokefan

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Re: F100 Yamaha Age/Identification with serial number label painted over!

Hello again, I don't want to be a nuisance and start PM'ing people directly that might be able to help but you know the old saying, if you need something done, ask a busy person!

I was really hoping someone could help where the main Yamaha dealer can't?
 

Twostrokefan

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Re: F100 Yamaha Age/Identification with serial number label painted over!

@Ldavidgrover
sorry, I meant to add it's a carb motor although it could have originally been imported from the US. They're a popular item on the used import market over here. I understand they're often used for commercial fishing in the US where [FONT=arial, sans-serif]they[/FONT] rack up high hours but at near idle revs making them a good option for use on a sports boat that does 50 hours a year.
 

Ldavidgrover

Petty Officer 2nd Class
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Feb 22, 2012
Messages
197
Re: F100 Yamaha Age/Identification with serial number label painted over!

The carb motor was 1999 to 2002 or 3
 

Twostrokefan

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Re: F100 Yamaha Age/Identification with serial number label painted over!

Good point - thank you - but I think this was sat for a long time before being installed. It does have the smart engine meter which shows engine hours as only 200 or so and the engine itself is in pristine condition. Just going by the likely age I'm going to order a timing belt. Apart from the timing belt I want to be able to identify the serial number for ordering parts etc but it seems no-one knows of anywhere else to find the serial number other than the transom bracket ? :(
 

Ldavidgrover

Petty Officer 2nd Class
Joined
Feb 22, 2012
Messages
197
Re: F100 Yamaha Age/Identification with serial number label painted over!

They only made them for a few years in the USA My guess on the belt should be all the same part number.
 

Twostrokefan

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Re: F100 Yamaha Age/Identification with serial number label painted over!

They only made them for a few years in the USA My guess on the belt should be all the same part number.

I'd still like to get the serial number somewhere on the engine if only to ensure it's properly covered by the insurance policy! I know Mercury put it on the engine block on the starboard side, Yamaha must put it somewhere other than a little sticker?
 

Twostrokefan

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Re: F100 Yamaha Age/Identification with serial number label painted over!

Eventauly found that Yamaha fit a white circular sticker to the top of the engine with the serial number - you may have to remove the timing belt cover to read it but I've seen it on three different F100s.
The serial number allowed part ordering with confidence so we did get the timing belt replaced. Turns out it's pretty much universally the same part# belt on all the F100s and F115s.
 
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