Should the motor be mounted in the top hole or one hole down? The reason I ask is that when I have people in the front of the boat I can't trim motor up much. It causes the front to plow and if I trim it sounds like the motor is cavitating.I would like some prop suggestions also it is a 2011 2274GLI with 115 Merc. Thank's for any help.
Motor mounting
- Thread starter ranger45
- Start date
spinzone
Well-Known Member
Ranger,
My Merc is mounted in the 2nd or middle hole. I also have the prop blowout when too much weight is up front and I attempt to trim the motor too high. Dispersing the weight when trying to run close to top speed is my solution to alleviate this issue.
9 times out of 10, we are running with 2-4 people on board and don't have this issue, it only seems to happen when we have 10 or so on board.
My Merc is mounted in the 2nd or middle hole. I also have the prop blowout when too much weight is up front and I attempt to trim the motor too high. Dispersing the weight when trying to run close to top speed is my solution to alleviate this issue.
9 times out of 10, we are running with 2-4 people on board and don't have this issue, it only seems to happen when we have 10 or so on board.
Link
Moderator
Spinzone, is this how it originally came from the dealer or did you move it to enhance performance?
Bamaman
Well-Known Member
I also have the same problem. Put too much weight in the front, the back of the boat rises and the engine ventilates. My other problem is that I have a 20" motor off a bass boat--instead of the 25" motor most people use on pontoons. When I have too many people up front, I have to ask people to move to the back.
But when the problem is not experienced, my boat is pretty fast on top end.
My best solution would be to install an adjustable motor mount and experiment lowering the engine a few inches.
A different prop (less pitch) might also help.
But when the problem is not experienced, my boat is pretty fast on top end.
My best solution would be to install an adjustable motor mount and experiment lowering the engine a few inches.
A different prop (less pitch) might also help.
spinzone
Well-Known Member
Link,
This is how my dealer set it up. If I have a light load, I can't complain. The boat rides so nice. With a full crew, I need to slowly increase speed to max rpms and adjust trim in small increments.
This is how my dealer set it up. If I have a light load, I can't complain. The boat rides so nice. With a full crew, I need to slowly increase speed to max rpms and adjust trim in small increments.
IMHO, a hydraulic Jack plate is the invaluable, subject to budget....They cost up to something like 11-1200.00.... Props are hard to size, because of the ever changing CG on a pontoon boat. However, the ability to raise and lower the engine creates a controllable horizontal thrust line. Then, you can dial in the prop.
Bamaman
Well-Known Member
I agree with the hydraulic jack plate. You've got to be careful to keep the engine as close to the boat as possible. For example, a 10" jack plate would put extreme leverage on the engine mount, and could possibly cause a structural issue.
Too bad hydraulic jack plates are not a little more reasonably priced. The manual plates are less than $300, and easily adjusted. You'd just have to do some experimenting for the size load you'll be carrying and with the prop.
The hydraulic jack plate might be worth the investment if I had a high performance tritoon with a 200+ hp motor or if I often carried varying people loads.
Too bad hydraulic jack plates are not a little more reasonably priced. The manual plates are less than $300, and easily adjusted. You'd just have to do some experimenting for the size load you'll be carrying and with the prop.
The hydraulic jack plate might be worth the investment if I had a high performance tritoon with a 200+ hp motor or if I often carried varying people loads.
Considerations:
1) Subject to trailering, the Hydraulic Jack Plate is used to raise the engine vertically, ILO tilting. Tilting potentially fuel floods the engine cylinders and/or creates dry cylinder bores. Also, tilting adds stress to engine mounting brackets and transom. A known band aid, is use of a support leg between the engine and trailer, though is not ideal. IMHO, Yamaha has only a partial solution with bumpers between the the engine mounting brackets. The bumpers don't provide a total solution.
2) Subject to shallow water/draft, the hydraulic Jack Plate is used to address that issue.
3) The 10" Jack Plate can place the "prop" and "low water pickups" into cleaner water. Both will preform much better. Yes, a Gusset design "must" be included in the installation. [We use a 6" set back/gusset system, w/the 350 Yamaha, now the scheme has been successfully tested and a 3" spacer block will be added.][it is thought, the spacer block is safer than a 9-10" assembly, because of concern for Jack Plate integrity, with that engine]. A lesser Wt. engine should work well w/ a 10" Jack Plate/gusset system.
4) Subject to CG/loading, the Hydraulic Jack will out preform a manual Jack Plate.
Last edited by a moderator:
spinzone
Well-Known Member
Just received 2 stilleto star II props for testing. My son was born last Wednesday so it'll be a few weeks before I can get out again but I'll let you know what rpm and speed figures I am seeing out of these two dia and pitches.
Link
Moderator
Boy I wish we could hook up to test those props. Be cool to compare our 2 different toon configurations with the same conditions...
spinzone
Well-Known Member
Fyr, PM me your email or phone and I'll get in touch a week or two before to schedule time with you. I think it would be really cool to see how well they work on your boat too.
spinzone
Well-Known Member
Thanks, Link! I've got a new crew member and fishing buddy now!