iveasmalta
New member
Hi guys, i'm from Germany loving these little Japanese malta outboards since years. Found this forum and hope to get the last missing pieces in the malta puzzle. But -to get- means -to give- as well...
First of all: There is absolutely nothing done on the Maltas by the japanese wich makes no sense! There is nothing to find stupid or to be easily improved. All i will write and/or commend its just my personell thinking!
Quite often the cooling system is discussed. As well known, there are depending on the year of build some without (older ones) and some with a pee hole bore.. The pee hole bore is drilled into the incomming pressure channel due to the problem, that if the malta is stored laying on the handle side while th impeller is sealing gfood enough. the motor will not drain all of its water. (freezing risk) The Japanes did hit 2 flys with one hit drilling in a 2mm!! hole getting the freez risk reduced an da detector for a correct working impeller.
The water is comming from the impeller pump and raises up the pipe to enters the (right) handle side in the upper shaft section. From there it enters the block and does a 90° turn arround the hottest ares, the exhaust channel. (very tiniy section with a high risk of getting blocked) a bore leads the coolant futher up into the upper 1/3 of the outer area of the cylinder bore (second hottest area) from there the head gasket leads the "flow" behind the combustion area to cool from the top side. The "flow" is generated more or less by restricton walls, and lager and smaler cross sections. The largest channel section leads the coolant from the 1/3 of the upper cylinder to the thermostate . If this is closed or blocked. no circulation can happen. So while double check if the coolant comming out of the pee hole is spraying mare or less you know if the thermostate is open/blocked or not.
After passing the open thermostate, the coolant is leaded through a passage directely into a pocket style area the opposit side of the handle bars upper shaft. (to get the litlle block a little more cooled symmetrical.
Drilling a 2mm bore into this" hot" area pockset style area can be done, but always together with the max 2mm!! pee hole on the opposit side.
The Malta is designed to run on a quite low temperture. 2 stroke outboard oil with 1.100 as recommended must be used to prevent carbonizing. 2 stroke scooter oil or mixtures richer than 1:100 will give significant disantvantages.
Following pics older/newer Malta upper schafts sections with/without pee holde and measurement to drill a 2mm hole into older ones
First of all: There is absolutely nothing done on the Maltas by the japanese wich makes no sense! There is nothing to find stupid or to be easily improved. All i will write and/or commend its just my personell thinking!
Quite often the cooling system is discussed. As well known, there are depending on the year of build some without (older ones) and some with a pee hole bore.. The pee hole bore is drilled into the incomming pressure channel due to the problem, that if the malta is stored laying on the handle side while th impeller is sealing gfood enough. the motor will not drain all of its water. (freezing risk) The Japanes did hit 2 flys with one hit drilling in a 2mm!! hole getting the freez risk reduced an da detector for a correct working impeller.
The water is comming from the impeller pump and raises up the pipe to enters the (right) handle side in the upper shaft section. From there it enters the block and does a 90° turn arround the hottest ares, the exhaust channel. (very tiniy section with a high risk of getting blocked) a bore leads the coolant futher up into the upper 1/3 of the outer area of the cylinder bore (second hottest area) from there the head gasket leads the "flow" behind the combustion area to cool from the top side. The "flow" is generated more or less by restricton walls, and lager and smaler cross sections. The largest channel section leads the coolant from the 1/3 of the upper cylinder to the thermostate . If this is closed or blocked. no circulation can happen. So while double check if the coolant comming out of the pee hole is spraying mare or less you know if the thermostate is open/blocked or not.
After passing the open thermostate, the coolant is leaded through a passage directely into a pocket style area the opposit side of the handle bars upper shaft. (to get the litlle block a little more cooled symmetrical.
Drilling a 2mm bore into this" hot" area pockset style area can be done, but always together with the max 2mm!! pee hole on the opposit side.
The Malta is designed to run on a quite low temperture. 2 stroke outboard oil with 1.100 as recommended must be used to prevent carbonizing. 2 stroke scooter oil or mixtures richer than 1:100 will give significant disantvantages.
Following pics older/newer Malta upper schafts sections with/without pee holde and measurement to drill a 2mm hole into older ones
Attachments
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Yamaha Malta Kontrollstrahl Bohrung Höhe.jpg -
Yamaha Malta Kontrollstrahl Mass von Breite.jpg -
Yamaha Malta neueren Baujahrs mit Kühlstrahlöffnung, selbe Ansicht wie bei Deinem nur halt mit...jpg -
Yamaha Malta, Wassertasche für Kontrollstrahl, du hast Platz satt.jpg -
Yamaha Malta, wenn Du den Motor drehst dann sieht es bei Dir so aus.jpg