Far2hip
Seaman
- Joined
- Aug 8, 2015
- Messages
- 57
I have a Mercury Classic 50, 45hp 4cyl 2-stroke, serial# 0C133460 attached to my 1964 14' Arkansas Traveler that I recently rescued from the woods and did a superficial restoration. Very cool little boat! I replaced the old frozen Evenrude Lark III with this Merc and the motor runs and pulls super strong with one constant issue. At the upper range of RPM's it will bog down a bit and feed back a bit of a fluttering sensation that will persist if I don't back down to feel out the "sweet spot" to prevent this from occurring. I got the prop situation dialed to the level capable with this issue and have zeroed in on the Spitfire 4-blade 10.6"x 12"p that pulls this thing out of the water and on plane like a monster within about 6 seconds, rockets to 25mph on the GPS, and then hits this wall of fluttering that pins me there at 25MPH and I have to back off the throttle to get to the sweet spot again. The RPM's at that wall is around 4800 and the recommended range for this motor is 5000-5500. When it back off and get to that sweet spot then push the throttle to go up to WOT, it feels like a bogging affect and then begins to start with the fluttering effect again. If I force a quick blow out of the prop it will jump quickly into that range with no load so it is an "under a load" issue. When I installed 3 blade 16 pitch during my prop testing, the boat went to 29 mph at the same RPM wall which makes sense given the added pitch.
Can any of you point to where this issue may arise from and explain the reasoning why it would occur from what may be suggested as a possible resolution of the issue?? I can feel this thing wanting to go and it is smooth and strong on the hole-shot. Can feel it in the seat of the pants with 2 big guys on board and 12 gallons of fuel. But I would love to have that 25mph be my cruise and see 30 for that smooth water upper speed range with this thing if I could. Any help would be great and I can do the work myself with some sound advice!
Thank you VERY kindly!!!
Can any of you point to where this issue may arise from and explain the reasoning why it would occur from what may be suggested as a possible resolution of the issue?? I can feel this thing wanting to go and it is smooth and strong on the hole-shot. Can feel it in the seat of the pants with 2 big guys on board and 12 gallons of fuel. But I would love to have that 25mph be my cruise and see 30 for that smooth water upper speed range with this thing if I could. Any help would be great and I can do the work myself with some sound advice!
Thank you VERY kindly!!!
