Currently have a bd5500 on a 16x44 w/ hunt deck gator trax. On a new prop I see speeds of 30 - 32mph...

These are the upgrades I'm doing as we speak:

- bps q muffler

- bps cam

- high-rev coils

- aftermarket bps lifters


What do you think ill see outta my setup after upgrades?

27

Much better load carrying capability and some top end from the high flow exhaust.

I still hit rev limit now with 2 hunters, 5 dozen decoys, and a dog but I'm also seeing 28mph-29mph with that load too

I can't imagine my load capacity getting much better than it already is

I had 5 people in my boat with a 50qt cooler filled with ice/beer and was getting same as my hunting speeds

Wait till you run with that BPS cam and high flow muffler.

The coils will let the motor run where its supposed to, 4300 is way too low for dual carbs so hitting the rev limiter is expected.

I've never modded a motor or ridden in one with a aftermarket cam and all the works....and I've only ridden in one boat with the 7000 so I don't really know what to expect ....

I absolutely love my motor the way it is now but for only about $800 more I can have it running with the best of the best



.....And any suggestions on gearing or prop setups in order to be able to increase my top end speed

Hopkins props?

Anyone tell me a lil info on them and their products?

By 'BPS lifters', I assume you are referring to valve spring shims (which you will need to have installed to keep your valves from floating). The BPS forum has a DIY step by step thread to install them w/o removing the heads. If you haven't ordered your parts yet, I would suggest IM heads before doing the cam. Advantages are: 1) they are much less involved to install. 2) The heads come ported, with the valve springs shimmed already, stainless steel one piece over sized valves, and decking to increase compression. This will give you increased power and ensure the valves are seating well. Do a search on here for 'stock valves suck'. Even though your motor seems to be running with good speeds and power now, leaking valves just rob power from the motor and the leaking intake valves are a common failure point on stock heads. For most motors its just a question of when this will occur, not if. Doing a valve job on the stock vavles/seats has proved to only offer short term improvement (needing to be re-worked again in a couple of years -$$) vs. resolving the problem with SS one-piece valves.

On 'gear ratio', depends on what gears are in your outdrive now. Most BD5500's come with a 40 tooth top cog and 46 bottom (lowest ratio they make) in an attempt to keep it off the 4300 rev limiter as much as possible. That motor was designed with the high rev coils in mind (they were in development when the motor was released). Pop your clutch cover and the installed cogs should be written on the clutch bell housing. Adding high rev coils you will have 400 more RPM to play with in your current setup, however you are adding other mods that will increase your RPM at the same time so you need to see where you are running after your mods and adjust if needed- each setup is different. If you find you are running 4500RPM with target load after installing your mods, you have the option of installing a larger lower cog to increase your hole shot (will raise your RPM).

On props, the MB big blade is hard to beat for overall performance and comes at a very reasonable price. Using prop pitch to increase load and fine tune your max RPM (along with gear ratio) is another option but just not as cost effective because its a wear item needing to be replaced over time. It depends on conditions you run and how much wear you put on the prop to determine the implications of going this route. The Hopkins 12P prop is much more expensive than a MB big blade and is an ongoing expense to maintain over time. I have had Hopkins add pitch to MB BB props but the results have been inconsistent from one prop to another. Of the three I had re-worked by them, only one was really good and noticeably better than a stock BB. I had the last prop that was re-worked by Hopkins scanned by another prop shop using the Prop Scan process/software and the results (overall pitch and blade to blade comparison ) were very poor and I won't use them again. I had additional pitch added to a BB and measured using Prop Scan and it was the best prop I have run, allowing me to run my CDI with 45mag internals, single carb, and IM heads with 38/50 gear combination, snap your kneck hole shot, and stay off the 4700 rev limiter but that prop was expensive. I personally have not run the Hopkins 12P prop so I don't have first hand experience with it, just giving you things to consider when setting up your combination for RPM. Note, MB is working on some different props for their new Sport V (basically fixed gear ratio ordered with the motor) that may be another option down the road.

Finally, the BPS forum DIY section has step by step instructions for several of the mod options- Installing IM Heads, Cam Installation, and Changing the Gear ratio. Pay particular attention to the re-installation instructions on the Cam Install to ensure you have a good seal on the case gasket to prevent oil leaks.

I already have iron mountain heads

The only thing that ill lack after these upgrades will be the bps piston/rods and roller rockers ....every other possible mod is already done or currently being performed

Idk...my MB dealer just said that he was gonna have to install "lifters" with the cam so I don't exactly know...maybe he meant push rods or roller rockers.. who knows???

you have to install new lifters with a new cam, lifters are what rides on the cam lobes. believe you get new lifters with a new bps cam

you do pay for new lifters

Anyone have all the upgrades that I speak of?

Done...

GPS numbers

Open, deep water slight chop with me and the mutt - 4520 rpm ....34.2mph

Prop has about 9hrs on it with slight wear....gonna run it tomorrow with brand new prop

Should have put some pistons and rods while you where in there. I'm fixing to to add cam and high revs maybe bottom end too looks like it helped yours for sure

So your getting 4500 now. I bet it feels allot stronger. Seems like mine wants to still rev. Up then damn there's the rev limiter. I think I'm doing coils now.then later adding cam and other stuff.just to see what it does in steps

I'm actually getting all the way up to 4700rpms but I just saw the fastest speeds at 4520rpms

That's cool. I ran mine just a little bit ago. I've got a geaux 1754hd empty I'm able to hold 30-31 deep water. Every now in then it will bump 32-33 in shallow water. I'm thinking with just coils I'm going to get around 33-34

Flat empty with just me I can only get it on plane at full throttle then I have to run about half throttle to stay off limiter. You can tell its got more