toolz

I have a '91 27 Fountain with a 290DP drive. The drive drifts in when under power, but works fine otherwise. Is the problem more likely to be a bad cylinder, or the pump? There is no external leakage. Thanks for your help- Toolz

fund razor

Mebbe you got air in the system. Air compresses. Oil doesn't. That would explain the compression under load and lack of leak.

AGGRAVATION28

I second that idea....has the system been opened recently for any reason? Let me know what you find out. I've got two of those things on my 30 Velocity...no problems but since they're not Merc I try to learn all I can. What power are you running thru it? Any Other problems?

Thanx,

Skip

toolz

Thanks for the responses. I don't think the system has ever been apart. It drifts down, I trim it up, and it gradually drifts down again. Takes about 90 seconds. Im assuming the actuators are two-way, meaning that if one is leaking past the piston seals, it will drift without any external leak. It's either that, or an internal leak in the pump valving. I just don't know where to look first.

The motor is a basic 300 hp 454 now, but the new 555 is done, and will probably get installed this weekend, since I've got three days for the 4th. New motor makes about 630hp, so were gonna see what the Volvo will take. I'm not a real aggressive driver. From what I've been told, I don't expect a lot of problems- we'll see. Thanks again- KB

toolz

Aggravation- what props are you running? I'm using a set of C4's now, and I have a set of C7's for the new motor, but I don't think it's going to be enough. I also machined a set of E4's to fit (on the advise of Reindl), so I'll give them a try. Please let me know what speed/props you've had success with. Thanks- KB

Russ G.

Hey guys I have a dp volvo drive also. Does any one do performance props for these drives.

Russ

toolz

Glad to see a few people with these drives- no body ever seems to talk about them.

Russ- I read in an old issue of Hot Boat that Hill Propeller either makes or will modify the props, but I emailed them and got no response. I'd like to find someone that knows about them, also.

Russ G.

I know toolz, I wish I had a Bravo for the pro selection. I bought my boat used with a new Volvo 502 DP drive set up on it. That drive looks very beefy! Its a 25 Checkmate. I just painted it its in the Checkmate section on this site. Everybody said that drive waist horsepower. I have run 73.1 with Gps with my boat so far. Its the 4th time out and I still have a 1/2 tank in her. Maybe with more time driving this boat and a 1/4 tank I might find some more speed. O-ya I,m tacking out at 4,700 I have to much prop right now. So I think there is even more speed if I can get to 5,000 or so.

Russ

AGGRAVATION28

toolz....

I'm running C-7 props with these puny 350 cu in motors...could use a few more rpms and thinking about getting a little work done on them but had other non drive issues to deal with first.

Can't wait to hear how the drive holds up under your new power. I would think with sensible driving it should be OK.....any idea how many hours are on your drive?

Good to hear there are others with these drives out there...............always been a Merc Bravo man but this boat was priced right and in good condition so I took a chance with the Volvos. So far, so good.................I just take it easy.

Skip

toolz

Russ- 73mph doesn't sound too bad to us guys that don't have $300,000 to spend. Sounds like you're on the right track. What props are you running?


Aggravation- My drive has 600 hours on it, and doesn't appear to have been apart. It's tight, and works fine. I may be in for trouble with the big motor, but I'll fill it with synthetic lube and hope for the best. If it breaks, I'll fix it. What speed are you getting from your C7's? I'm shooting for 70+, and built the motor to turn as much as 6000, but props are the big question.

Thanks for the responses. Toolz