V4 Crossflow 100hp, 125hp identification and thoughts.

[Rabbo]

Hi all, first post (not first read) so sorry for any newbish behavior.

Bought a heap of 4 engines of which I´ve managed to identify all but one. Got a 72 125hp (modded for swedish classic off shore so not factory spec), 79 100hp and a 77 140 in pieces but with all the good parts left.

The last one I think is a 71-72 100hp, it has the distributor ign but with trigger instead of points. cross checked with boats.net on nmbrs for the jets, heads, carbs and it points to a 100 hp. Did a comp test and it was 150 on right bank and a little lower on the left which I thought was high for a hundred? My 76 135hp did have something similar and that´s supposed to be high comp right?

Qe: does the early 100hp have that high comp and are there any other specific hints to look for to make certain of year and hp? Of course the plate on the rig is gone and nothing on core plugs. Also I finally managed to get it started after finding that the amplifier gets no current when cranking, doubled the lead from ign switch but didn´t help, now took

power directly from starter circuit. Could starter and solenoid be bad and eat up all power?
Also I think I´ve read about difference in block bore sizes but haven´t found any details on what years and hp that it really changed. I´m guessing that if this engine is early 70s 100hp it will be the smaller cui size? What would be the internal difference to the same year 125? Carbs, heads and porting?

Thank you all for all the great reading on these engines so far, love it.



Sorry for my uploading skills, apparently not satisfactory..

[James45157]

there was one year that the bore was difference cause you could but the crank out of the old 1964 90 hp and it would give you 89 ci which i know a guy that did it he used 8 barrel intake of a race motor he turned it 8600 rpm changed rod bolts every 20 hours iwas at his place saw it cool he said it made 160 hp on paper

[James45157]

i think that year was 96 ci not sure on what year been a long time ago

[Rabbo]

Thank you.