tilt & trim

[1966starcraft18ft]

Hey guys, It's been quite a while since i posted on here.

My family just aquired a 1996 Monark Sunspa 260 pontoon that was repowered with a 1988 Force 125. ( model 1254XS8A). Anyways, we Bought it on Friday night, spent all day saturday cleaning it and chasing down why the fuel gauge didn't work and just all around learning the craft. We took it out sunday(yesterday) and I couldn't get it to plane out. i tried trimming it and no joy. if I was sitting still and trimmed the motor up and then took off, i could feel it start to jump out and then nose dive and plow through the water. I did a lil investigating and the tilt cylinder( the one that looks like a shock) settle quite quickly( from full up tilt to settling down against the trim cylinder( the horizontal one) in 3 minutes roughly) once the motor is down again the trim cylinder, its rock solid till you trim down and then it bottoms out.

my question is, do the tilt cylinders contribute to the trim function or is there only so much trim that can happen.

sorry for the long post but i wanted to share our new watecraft and give a lil history on the craft.

 

[topgun3690]

my question is, do the tilt cylinders contribute to the trim function or is there only so much trim that can happen.

The tilt and trim work independently.....when the trim reaches it's limit the tilt cylinder takes over. If your engine bleeds down (won't stay up) take a look at the top of this forum in the FAQ section......there are several threads about trouble shooting the T&T system there......

 

[jerryjerry05]

The T@T is a 2 part system. The trim operates until fully extended then the tilt takes over.
The shock cykinder is just that a shock and it doesn't do anything to help the T@T function.

 

[1966starcraft18ft]

Ok. Cool. Ya I’ve read through those and I’ve diagnosed it to be the valve body issue but wasn’t sure if the tilt ram just didn’t have enough gusto to hold motor up under power. This system is new to me. All I know is the I/o stuff. Thank you for the insight guys.

What fluid do I use in the system? Same stuff I used in my I/o?

 

[topgun3690]

Use SAE 30 non detergent oil......fill when engine is fully down. Tilt system won't hold under power, that is where the trim system works.

Regarding the valve body, I would try to repair the original one using the info in those repair threads.......the replacements available on ebay, etc. are foreign (China) junk that might not work right out of the box.

 

[1966starcraft18ft]

. Thank you again for all the help.

 

[topgun3690]

If you decide to repair the VB I wouldn't mess with the pump part.....there is nothing to fix in there and may never get it back together if taken apart.....FYI

 

[Jiggz]

If the tilt system is draining down, that also means the trim system is also draining. The two systems may have different names and purpose but they share the same fluid and pressures. So the solution as you mentioned is to replace those two seals in the valve body. AS MENTIONED BY TOPGUN DO NOT OPEN THE PUMP PART! That only has springs and ball bearings as check valves and they are all different and hard to put back together. Follow the instruction repair thread. And you may get lucky and find the seals on amazon for cheap.