Increase Hp for Yamaha 5hp

[matt h]

can this be done,
have a small SIB and a Yam 5 hp short shaft, i have to run it in first being new, But can it be tweaked and how to push out more Horses??
re jet and ign adjust maybe??
it would be great if the Sib was more exiting than i think its going to be!!
Cheers ALL

[Locozodiac]

Originally Posted by matt h

can this be done,
have a small SIB and a Yam 5 hp short shaft, i have to run it in first being new, But can it be tweaked and how to push out more Horses??
re jet and ign adjust maybe??
it would be great if the Sib was more exiting than i think its going to be!!
Cheers ALL

If the next model for example a 6 HP would have the same cubic centimeters, lets say 100 CC compared to the same 5 HP by changing jets on the carb and placing the same jets as of the 6 HP , would have a nice converted 5 to 6 HP. If not mistaken the next Yam engine would be a 8 HP, perhaps with larger CC. Seems the 5 is a 4 with better jets & output.

As a comparison a Tohatsu 10 & 15 share the same CC engine, about 250 CC, to convvert simply change 10 HP jets for 15 HP jets, some models have air restrictors too, get rid of them.

Happy Boating

[Chris]

The largest engine in that range is the 5HP so thats probebly not an option, Why not try adding nitrous that should give it a bit of oomph.

Alternatively you are looking at port modifications skimming the head to run at a higher compression etc. Not something I would suggest you do to a brand new engine.

[9D280]

Originally Posted by matt h

i have to run it in first being new,

Errrr Warranty?

If it's new would you not have been easier & quicker just buying the bigger engine in the first place???? You could probably pick up a nice 6 or 8 secondhand for the same price as a new 5.......