Hi GUYS..I have a LYNX that I have now decided to fit a MODIFIED KB 3.5 that was done by James.(THANKS JAMES ITS GREAT). ANYWAY i have fitted the engine and measured the prop face to the back of the transom and get exactly 5 and a half inches bearing in mind I have fitted the engine to an adjustable motor mount from Vince in California.Now on a previous LYNX a mate of mine has he has a 0S21 XM and his engine is set to 6 and a half inches from the prop face to the transom.Does anyone know if my measurement will be ok as I dont think there are many KB engines out there fitted to this hull as apparently is was designed using the OS21..Thanks Baz( UK )
Would you like a PDF file of the setup instructions? Your setup will be too short. You will need to make a spacer. To quote the manual:
"The O.S. 3.5cc outboard engine can be mounted to the transom using the factory engine mount. The Lynx was designed and tested using the O.S. and the Lawless lower units. Your prop hub-face* should be 6.0” +/- 1/8 from the transom (no matter what lower unit or adjustable engine mount you choose). This distance allows for easy race trim. This is a critical dimension. If you neglect this detail, you will never see the full performance potential of your Lynx.
*Prop hub-face: The front face of your prop hub. The joint between the propeller and the propeller dog (cog) is used as a generic reference point for prop placement.
......
Initial vertical prop placement for 3.5cc Modified: With zero thrust (prop shaft perfectly level with the sponson bottom), the lower edge of the prop shaft bullet casting should fall between even with the sponson bottom or 1/16 above. Drill engine mount holes so that you have equal vertical adjustment from this point.
Initial vertical prop placement for 3.5cc Stock: With zero thrust, the lower edge of the prop shaft bullet casting should be 3/32” to 1/8” above the bottom. Drill engine mount holes so that you have equal vertical adjustment from this point.
Proper thrust angle setting: 0 to 1/8 degree of negative thrust (maximum) "
"When using Lawless lower units with other mounts, be sure to check the prop hub-face spacing and make sure it falls with-in 1/8” of the specs mentioned above.
When using other engines and mounts that don’t place the prop within the suggested location, the boat may experience trouble launching and have difficulty trimming correctly. This model is very sensitive to prop placement and C/G."
"FOR K&B LOWER UNITS:
When using the K&B Outboard lower unit, a 2” extension to the factory motor mount is required. This boat will not function correctly using a K&B lower unit unless the recommended prop face location is observed."
