6hp compression

[nwcove]

Re: 6hp compression

the diameter and pitch should be stamped on the prop(s) . just be carefull not to over rev the motor ....it should humm...not scream!

 

[Robert Hodges]

Re: 6hp compression

So I finally got the new head gasket in the mail and also put on the two blade prop. Went for a test run and went a mile in 4.75 min. Thats around 13 mph. Not bad. Motor sounded good but I feel theres a little more in there. The compression came to 80/85 per cylinder. About the same as old head gasket. Question.........does more comp. mean more h.p. wich means more speed? New Rings maybe? Mr. JB, thanks for the info on the 2blade props. That helped!

 

[nwcove]

Re: 6hp compression

jmo, but 13 mph for the six with the prop change is very good. the engine was designed to run at a peak rpm...say 5000. you may or may not be getting to that rpm. ( as mentioned in an above post, a "tiny tach" will tell you the rpms at wot.) also, as i mentioned before, the 6 may be a bit longer than the 4....measure both from the clamp to the anti-ventilation plate thats just above the prop....post back with the measurement.

 

[Robert Hodges]

Re: 6hp compression

From center of clamp down to plate is 15.5 on the 4hp and 16.5 on the 6hp. I have no clue as how to use a Tiny Tach but I believe I'm going to find out. Where do you get them and how much? Easy to figure out?

 

[nwcove]

Re: 6hp compression

before spending money on the tiny tach ( usefull tool for small obs tho) try clamping the 6 the one inch higher on the transom if possible. you may be surprised at what the correct motor height will do for rpms , just make sure its clamped tight and pumping water. yer not gunna get much more out of that motor, but small tweaks can make a difference.

 

[Robert Hodges]

Re: 6hp compression

Will do. This week am going out to Lake O to scout for the upcoming duck season but will be able to get to the smaller lake ( my track ) to do a time trial. Thanks and will write after the test!