Yamaha 55be (circa1991) service manual & general help with under-powered performance

[Neils6896]

Evening all, it’s great that you’re all so passionate about what you do and I can’t thank you enough for your help and advice. I guess there is no right or wrongs with these things there’s just so much involved in them and different ways/methods of getting them running right.

just to update you... 99YAM 100% spot on with the gear. Covered with rag and gave it a twist and she popped back into neutral thank you.

so I cleaned the carbs as best I could, I don’t really have the confidence to tackle the timing/syncing etc so I will have to work up to that.

someone suggested running SeaFoam through it to give the carbs a really good clean out (as I suspect it sat/was neglected for a while until I bought it) so I mixed that in with the fuel and used a 75:1 ratio (that old debate) to really clean out all the valves etc (will probably switch back to 50:1 for preservation).

to sum up I took her out tonight on the river and she is running better! I know I shouldn’t (esp here in the UK) but I opened her up a little bit and she started to plane and got up to 23 knots before I bottled it and eased off again.

taking her out in the harbour for a proper test run to see how she goes on Sunday and will update further.

will check in the daylight tomorrow for any signs of that fuel leakage.

thanks again everyone.

[TownsendsFJR1300]

Seafoam is good stuff but Yamaha's RINGFREE is considerably better (IME), especially used in a "shock" treatment:

https://www.shopyamaha.com/product/d...?b=Search&d=34

Instead of normal use of 1oz / 10 gallons, SHOCK treatment is 2oz / one gallon. Three gallons should be plenty

[Neils6896]

Seafoam is good stuff but Yamaha's RINGFREE is considerably better (IME), especially used in a "shock" treatment:

https://www.shopyamaha.com/product/d...?b=Search&d=34

Instead of normal use of 1oz / 10 gallons, SHOCK treatment is 2oz / one gallon. Three gallons should be plenty

Thanks bud Probably going to need that in the spring.

[Neils6896]

Hi All,

Took her out on Sunday and was very pleased with the performance. She eased along at 27 knots which i guess is about where it should be?

Hope the link works but here's a short clip of her in action: https://www.facebook.com/556898375/v...8501660988376/

[Neils6896]

My only concern when we got back to shore was it looked like i had it bleed?! I took the cowling off and again no obvious fuel leeks etc. Any idea what this could be?

[TownsendsFJR1300]

My only concern when we got back to shore was it looked like i had it bleed?! I took the cowling off and again no obvious fuel leeks etc. Any idea what this could be?

The brownish stuff on the edge? (I assume so)

As you've had prior fuel leaks, and no posting of it being repaired, I'd think you still have a fuel leakage issue.


Might want to degrease that lower cowling/engine over (especially by carbs) and "follow up on it.".
It's NOT fixing itself..

That much residue is coming from somewhere.

Probably being a major safety issue, bring it somewhere to check it if you can't find/remedy it.
Your life is worth the investment before that thing catches fire..


..

[99yam40]

I would be looking for where that stuff is coming from