Young Performance

It depends on the boat. As long as you have enough room to pull the exhaust and the heads, then they can stay in. I will do it on a few boats, but most it's just easier to take them out. In most cases, it takes longer to do it in the boat than it does to take them out and change everything with the engines on the stand. If you are just going to change the springs, etc only and not pull the heads to change the gaskets, then it certainly can be done in the boat. If you want to change the head gaskets as well (a good idea), then it may just be easier to pull them.
What is the boat? That will make all the difference.
Eddie

kragar

29 outlaw

BUP

iTrader: (9)

Yep U can leave the motors in the boat and get to the top end. The hardest part is getting the Gils exhaust manifolds off in the 29 Outlaw after that everything is alot easier.

See you jump off the Baja threads and got the answer U were looking for on HP500 -from the engine guy not the interior guy.

Never heard of anyone with a boat complain that there boat has too much power and would love to have less no matter what the boat size is.

I rather have too much power and not use it than have too little and spend out the azz to get more power.

You are buying the boat for yourself - get the power you want from the start.

The carb HP500's are darn good motors.

flying J

What would a fair price be to drop off pulled motors for Spring, Seal and retainer replacement? Also, can you reuse the head bolts if you were to replace the head gaskets?

pqjack

some people don't like the 110 center on the hp500 camshaft...care to comment on this?

Young Performance

You can reuse the stock head bolts as long as they are in good shape. They don't go into the water jackets, so that's not a problem like it used to be on the MK IV blocks. The biggest problem is the head. If water, especially salt water, has sat on top of the bolts, then the bolt heads can rust and get deformed and not be reusable.
You can expect about 10 hours or so to remove the accessories, intake and distributor, cylinder heads, change the springs, etc., set up and shim new springs, assemble heads and put it all back together. The price would depend on the shop's hourly rate. Mine is only 65/hr. Some shops are as high as 100/hr.
Any machine work would depend on what the heads look like. They may or may not need to be surfaced, they may or may not need a valve job. You can just lap the valves in and see what you have to see if they need a valve job, as long as the seats are in good shape.
The springs, retainers, locks, seals, shims, head gaskets, intake gaskets, exhaust gaskets, etc would run around $400-$450. That would put the total job for a pair of HP500's around $2100-$2200 off the top of my head.
Eddie

flying J

Thanks Eddie I'm looking at a 2000 model boat with a pair of these motors and wondered what I was getting into

Griff

Much easier to pull the engines and you don't have the risk of causing any dmage to the cockpit vinyl.
After a 50+ trips of climbing up and down into the boat and having to retreive tools and parts from the bilge bottom, you will agree.

I've done it both ways on single engine boats and would never do it with engine(s) in the boat again.

ROTAX454

Now there is some sound advice. The person responsible for the work can then properly inspect many other items. Example: The Merc coupler.

Also, no mention here about the Gil manifolds. Any cause for concern?

ROTAX454

Enough cam jockey's on this site to make your head spin. Go talk to rmbuilder on here. Get the straight talk on what cam to place inside those great motors.