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1991 Black Max 150 stalls when tilted

D

DonColliau

New member
I am having an issue that when I tilt the motor to operate in shallow water it stalls out. I can restart it quickly by choking it but it will quickly stall again. I can somewhat keep it from stalling by increasing the throttle every 10 seconds or so at slow speeds. It runs fine when tilted down with maybe the slightest hesitation when taking off.

I have no idea how to trouble shoot it or where to even begin. Any advice would be much appreciated. I assume that choking means its running out of fuel? There are no kinks or anything when tilted.
 
Could be an issue with the floats in the carb(s) - might be a simple adjustment (of course the carbs would have to come off and be disassembled - the "adjustment" is the easy part) :)

Old Tillotson carbs would puke gas out of the throats when you tilted the motor and it was tough to stop them from doing so. This has better carbs then those, but it was those old Tillotson's that would lead me to investigate the floats on your model...
 
galamb said:
Could be an issue with the floats in the carb(s) - might be a simple adjustment (of course the carbs would have to come off and be disassembled - the "adjustment" is the easy part) :)

Old Tillotson carbs would puke gas out of the throats when you tilted the motor and it was tough to stop them from doing so. This has better carbs then those, but it was those old Tillotson's that would lead me to investigate the floats on your model...
Click to expand...


How would one go about making that adjustment? Possible that it's all 3 carbs or just one?
 
Could be one or all.

To adjust the floats you have to remove and disassemble the carbs - so a manual and a few hours of your time is an absolute must.

Not something you can just "tweak" with everything in place...
 
galamb said:
Could be one or all.

To adjust the floats you have to remove and disassemble the carbs - so a manual and a few hours of your time is an absolute must.

Not something you can just "tweak" with everything in place...
Click to expand...


Would your assumption be that being on an angle that they arent opening causing it to starve for fuel or that they are not closing, causing it to flood?

Just curious if i am thinking about it correctly. Thanks for your time
 
Yes, that's the initial assumption that I'm working on.

If it runs fine "except when tilted" that would tend to indicate a fuel starvation (or total flood) when it is. And the carb floats (or bad needle valves/seats on the floats possibly combined with poorly adjusted floats) would be pretty high on the list of possible causes.
 
That gives me a good place to start. It sure seems like its starving to me especially considering it fires up immediately while choking. It also appears the floats pivot in a way that the more its tilted, the less the the float is submerged in fuel. The interesting part is a version of this will happen at a slight tilt and happen quicker the more its tilted. This long block was just purchased used from Miami and replaced the one that threw a rod though the case last week. That one ran great and i have even considered just switching the carbs out.
 
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