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Equipment & Gear => Power Equipment & RV => Topic started by: Stein on June 25, 2025, 07:50:38 PM

Title: 90's Yamaha no telltale?
Post by: Stein on June 25, 2025, 07:50:38 PM: Our Scout troop inherited what I believe to be a 90's Yamaha 15 we intend to use on our safety mini-RIB for canoe trips. I tried looking up the serial number and apparently it was made in Japan for the Japanese market and thus has zero info available online. I went through it, replaced a few things and it fires up first pull.

The only problem is that it doesn't seem to have a telltale which I thought were on all outboards. I did some Google-fu and it sounds like outboards from the 60's and 70's may not have them but I didn't see anything from the 90's.

My concern is that without one I can't verify the coolant system is working. The impeller looks great and there are a couple bypass holes above and forward of the prop that water comes out of when it's running so I'm mostly confident it is cooling.

Does anyone have experience with a motor like this make and vintage without a telltale?

I plan on taking it out for sea trials tomorrow but would like to be 100% sure before we do something that can't be fixed.
Title: Re: 90's Yamaha no telltale?
Post by: MADMAX on June 25, 2025, 10:04:40 PM: Your talking the pee-er ?

https://www.reddit.com/r/boats/comments/1la4tps/90s_yamaha_15hp_2_stroke/
Title: Re: 90's Yamaha no telltale?
Post by: RB on June 26, 2025, 07:05:08 AM: I was thinking same as MADMAX is it not peeing? Have had similar issues with my eight horse Honda bugs will clog up the pee tube and it will not pee. Took me a while to figure it out cause the hose was not easily seen. To my knowledge every outboard should pee, unless it is somehow air-cooled.
Title: Re: 90's Yamaha no telltale?
Post by: MeepDog on June 26, 2025, 07:51:27 AM: I had a 1975ish Johnson 15 that didn’t pee by design. I’ve never heard of that with Yamaha. Your best bet would be to clean out the passages or find some other way of verifying function because no coolant means toasted heads and bearings. Bad juju

Try running it with muffs instead of in a bucket and see what the water does.
Title: Re: 90's Yamaha no telltale?
Post by: Crunchy on June 26, 2025, 08:40:12 AM: Ive had the no pee a couple of times with different motors. I used weedwacker line to push through the pee hole and hose to clear the line. I also removed the hose from the motor and pushed the line into the engine as well. If that doesn't work you might need a new impeller. Plenty of YouTube videos on how to fix.
Title: Re: 90's Yamaha no telltale?
Post by: Stein on June 26, 2025, 10:41:15 AM: There is no hole as far as I can tell. I've looked it over several times, both sides, back, can't find a hole that water would come out of.
Title: Re: 90's Yamaha no telltale?
Post by: Longfield1 on June 26, 2025, 11:22:34 AM: Whats the model number?
Title: Re: 90's Yamaha no telltale?
Post by: Stein on June 26, 2025, 12:28:38 PM: Tag says:

Yamaha 15D
684CS 02562x

x is some digit that is too corroded over to read, maybe 9.
Title: Re: 90's Yamaha no telltale?
Post by: Stein on June 26, 2025, 12:31:54 PM: This thread seems to think it's a 1994 sold in Japan.

https://www.yamahaoutboardparts.com/forum/general-discussion/yamaha-outboard-forum/25037-yamaha-serial-number
Title: Re: 90's Yamaha no telltale?
Post by: Stein on June 26, 2025, 12:34:26 PM: When I went through it, impeller and seals all looked great, almost brand new. I couldn't find any water tube under the cowling or any opening anywhere I've ever seen a telltale opening, no holes above the waterline at all except the upper exhaust.
Title: Re: 90's Yamaha no telltale?
Post by: BigGoonTuna on June 27, 2025, 04:04:18 AM: It looks like according to the drawing on this page, there should be a connector for a telltale hose on the upper part of the exhaust cover (see #18 and 19):

https://en.impex-jp.com/catalogs/outboard/yamaha/15/6e8-1995-dark-bluish-gray-metallic-2-japan-42599/cylinder-and-crank-case-1640808.html (https://en.impex-jp.com/catalogs/outboard/yamaha/15/6e8-1995-dark-bluish-gray-metallic-2-japan-42599/cylinder-and-crank-case-1640808.html)

I compared the drawing to a couple US market 2 stroke from the 90s and they appear to be identical. I used to have a 1998 15hp and it most certainly had a telltale hose on it.
Title: Re: 90's Yamaha no telltale?
Post by: ASHQUACK on June 27, 2025, 06:50:54 AM: Crazy thought here, was it ever plumbed for a hot water wash sink? Shops do some funky stuff to plumb them in sometimes.
Title: Re: 90's Yamaha no telltale?
Post by: Crunchy on June 27, 2025, 07:31:16 AM: If it has an impeller it is pumping water somewhere to cool the engine. Boats.net and look at their diagram?
Title: Re: 90's Yamaha no telltale?
Post by: Stein on June 27, 2025, 01:23:57 PM: Thanks Tuna, I'll check that out.