Logo
FULL SITE MENU

"New-to-me" 70hp TLRU 6H3 starts first try but...

H

hpinfo

New member
Put the boat in the water today (opening day of boating season here in Seattle.) Should note that it had about 1/2 a tank (5 gallons) of 2 year old gas so I topped it off with 5 gallons of new gas and fuel system cleaner. After a few priming lever pumps, hit the starter and it basically fired right up. warmed up and moved away from dock, but as soon as I hit it to get on plane I get maybe 2 seconds of full power then it falls on its face. if I idle for 30 seconds, it will repeat the 2 seconds of full power. New primary filter and plugs. Also, removed air silencer and noticed the emergency fuel enrichment lever was in 'on' position. moved it to the 'normal' position and it will barely run. Restricted fuel? Ideas on where to look?
 
Update. Did the fuel bulb pump routine and it came up to full power for about 6-7 seconds, then back to no power. After that, the fuel bulb is rock hard and trying to pump it further does nothing.
 
if the gas is two years old has the boat set up with no running in 2 years?

the first thing i would do is get rid of the gas and start fresh....check the plugs to see if they are wet with the new gas when it fails..its probably time for carb rebuilds..
 
papyson said:
if the gas is two years old has the boat set up with no running in 2 years?

the first thing i would do is get rid of the gas and start fresh....check the plugs to see if they are wet with the new gas when it fails..its probably time for carb rebuilds..
Click to expand...

I realize the old gas that is mixed with the new is probably not 100% but that doesn't really explain the symptoms. Especially that when 'force fed' fuel via the bulb it ran at full power (briefly). Bad gas taken out of the picture, why would that be?
 
If the boat has been sitting for two years without the carburettors being drained completely first they are almost certainly in need of a clean out.

Stuart
 
DangarStu said:
If the boat has been sitting for two years without the carburettors being drained completely first they are almost certainly in need of a clean out.

Stuart
Click to expand...

Agreed. What would I likely find in the carbs? Water? Contamination? If that was present, would the symptoms be as described or would it just run rough and/or not start? The engine starts with no difficulty at all, only problem is when I try to draw HP out of it (use more than a trickle of fuel)
 
Often what you will find inside looks to me to be a cross between sand a salt. It is, I presume, a combination of aluminium corrosion and residue left by the evaporated fuel. Carburettors generally have a couple of jets: a main jet and an idle jet. It is quite possible that your main jet is blocked so it will idle but when the throttle is open the main jet can't deliver the required fuel so it goes lean and stalls.

Regards,
Stuart
 
If that was the case (main jets clogged) would idling for 30 seconds and/or pumping the bulb result in temporary full power?
 
So getting full power when pumping the bulb normally points to either a restriction in the fuel line (closed tank breather etc) or a failing fuel pump. At the same time I would expect the bulb to be deflated at the time of the stall though, not hard.

Stuart
 
Bulb was extremely hard. I had to let it sit on the bottom of the compartment and lean on it with a lot of force to get it to do anything. When I was prepping it for initial start, the bulb acted much more normal in that I could just squeeze it and feel the fuel moving through. one note - I didnt change the secondary (on the engine) fuel filter. Is this advisable or does the primary normally keep gross contaminates out of the secondary?
 
Back
Top