As some backstory, this is a 2001 BF40A that I got back in 2023. The boat it was on ended up being scrap and now I've been trying to get this motor running well enough to sell it. I have rebuilt the carb stack, synced the carbs, new thermostat, new lower unit (long story, do your basic maintenance folks), new fuel filter, all new gaskets for air intake and carbs as well as thermostat, new water pump (came on the new lower), new prop.
I'm running it on a stand in a 50gal drum with the top cut off. At idle I was getting very little water flow and the red overheat light on the remote would come on followed by a warning buzz. I pulled the lower and found that the water uplift tube had pushed the rubber bushing from the pump cover out of place and it was blocking things. I reassembled but it didn't get better. I started getting a lot of scale blockages in the tell tale. So I removed the tell tale and the fitting and at one point it was completely blocked by chunks of scale. So I scraped the scale out and then started running it for a few minutes every hour in vinegar in the drum. Although I got more scale out I still get very little flow at idle. And it get steaming hot. More throttle causes water to blast out of the tell tale and I don't seem to have any overheating problems until the 50gal drum gets warm. At idle though it overheats pretty quickly as I get very little flow out of the tell tale.
Idle:
Is the tell tale the water exhaust or just an indicator. I know that on my Yamaha T8 it is just an indicator and will never get warm (because a lot of fishing folks like to circulate the hot exhaust water from their kicker so they have warm water for washing hands after handling fish). You have to tap into the actual exhaust because the tell tall is before the engine. However Honda's tell tall water gets steaming hot which suggests that it is either the actual outlet or is after the motor. Also the Honda tell tale doesn't start until the thermostat gets hot enough to open. Then again, there is almost no pressure from the tell tale which would surprise me if it is the actual exhaust outlet. If the tell tale is not the primary cooling system outlet, where is it?
Also, I don't know if this is a me problem or if this is always a problem. If feel like my motor is idling too fast but if I slow it down it overheats from apparently not enough water flow (at least measured by the tell tale). I have no point of comparison. Do these motors always overheat after 5 to 10 minutes in a barrel? Are they just meant for higher RPMs and not idle all the time? My Yamaha T8 will idle all day long. Granted that is in a lake not a barrel that gets hotter with every minute.
I'm running it on a stand in a 50gal drum with the top cut off. At idle I was getting very little water flow and the red overheat light on the remote would come on followed by a warning buzz. I pulled the lower and found that the water uplift tube had pushed the rubber bushing from the pump cover out of place and it was blocking things. I reassembled but it didn't get better. I started getting a lot of scale blockages in the tell tale. So I removed the tell tale and the fitting and at one point it was completely blocked by chunks of scale. So I scraped the scale out and then started running it for a few minutes every hour in vinegar in the drum. Although I got more scale out I still get very little flow at idle. And it get steaming hot. More throttle causes water to blast out of the tell tale and I don't seem to have any overheating problems until the 50gal drum gets warm. At idle though it overheats pretty quickly as I get very little flow out of the tell tale.
Idle:
Is the tell tale the water exhaust or just an indicator. I know that on my Yamaha T8 it is just an indicator and will never get warm (because a lot of fishing folks like to circulate the hot exhaust water from their kicker so they have warm water for washing hands after handling fish). You have to tap into the actual exhaust because the tell tall is before the engine. However Honda's tell tall water gets steaming hot which suggests that it is either the actual outlet or is after the motor. Also the Honda tell tale doesn't start until the thermostat gets hot enough to open. Then again, there is almost no pressure from the tell tale which would surprise me if it is the actual exhaust outlet. If the tell tale is not the primary cooling system outlet, where is it?
Also, I don't know if this is a me problem or if this is always a problem. If feel like my motor is idling too fast but if I slow it down it overheats from apparently not enough water flow (at least measured by the tell tale). I have no point of comparison. Do these motors always overheat after 5 to 10 minutes in a barrel? Are they just meant for higher RPMs and not idle all the time? My Yamaha T8 will idle all day long. Granted that is in a lake not a barrel that gets hotter with every minute.