Fuel gauge to fuel tank

[Solarman]

Could have been trash in lines from deteriorating fuel lines/pump, or something is lodged on back side of needle valve seat (in one, or more carbs), possibly from rebuild of fuel pump - new/higher pressure again - pushed trash in lines after pump to carbs, restricting flow going into each bowl. This would cause the surging rpms like you said.

Sounds like carbs will need to be inspected and cleaned.

Take pics before removal to make sure everything goes back as it was, and record idle air-mixture screw adjustment for each carb, so they all go back same when cleaned. All idle air-mixtures should be identical/same setting for each carb.

Always use compressed air to blow through all the small air & fuel pas-sages once carbs are cleaned. Always reset float levels when removing needle-vavle seat to check for trash on back-side.

Good luck. Post back what you find out.

[welshspringer]

Solarman
The marine engineer came today as arranged, very busy bloke, waiting time 4-5 weeks. In short he serviced the carbs and jets were partially blocked, he tested the cylinders and all 3 returned 8 atmospheres. His words "engine in tip top condition.
Engine now waiting a sea trial next week hopefully.
Have an option to buy a Honda 50 - 4 stroke approx 10 yers old some years younger than my 2 - stroke Suzuki,, any comment???
The only thing I know in comparison is that the 4 stroke is better on fuel and noise.

[welshspringer]

Could have been trash in lines from deteriorating fuel lines/pump, or something is lodged on back side of needle valve seat (in one, or more carbs), possibly from rebuild of fuel pump - new/higher pressure again - pushed trash in lines after pump to carbs, restricting flow going into each bowl. This would cause the surging rpms like you said.

Sounds like carbs will need to be inspected and cleaned.

Take pics before removal to make sure everything goes back as it was, and record idle air-mixture screw adjustment for each carb, so they all go back same when cleaned. All idle air-mixtures should be identical/same setting for each carb.

Always use compressed air to blow through all the small air & fuel pas-sages once carbs are cleaned. Always reset float levels when removing needle-vavle seat to check for trash on back-side.

Good luck. Post back what you find out.

Engineer arrived today as arranged, yes there was a problem with the jets. All 3 cylinders tested and had excellent return figure 8 ats. Hopfully sea trial next week if weather is good, "THANKS".

[Solarman]

Good luck on sea trials.
A ten year old 4 stroke could be more problems than a 25 year old 2 stroke. You had better have a qualified honda mechanic test that motor before buying (do you know how well the motor was maintained?).
They may be a little better on fuel usage... but...
The weight of that honda would cost you more in fuel to carry itself. Lol

Good luck, let us know how it went when you have time.

[welshspringer]

Hi Solarman. At last my suzuki 65 is running like a dream, it has needed this work - carbs and fuel pump, it is now starting better than ever brfore and top end speed is terrific. I shall not be going for the honda, my 77 birthday today cannot see the sanity in expenditure.

[Solarman]

Smart move at 77.

You should always use a good fuel filter, to keep trash from the fuel stations to a minimum (cheaper stations usually have trash in fuel). Also, adding a little fuel additive to each tank of fuel, protects interior lines and rubber parts from cheaper ethanol blended fuels (bad for all motors).
Plus, never leave fuel sitting in carbs for over a month (if motor is oil injected - run all gas out of carbs while fogging motor - then drain remaining gas from carbs; and, if not oil injected - fog motor, then drain each/all carbs float bowls.).

Good luck, happy boating.