I have had my rig since February and only been out riding in deep water a couple of times. Today I went for the first ride since installing my Tiny Tach and uploading a gps app on my I phone, and i was upset to find that my top speed was about 16 mph at 3250 rpms average. Is this normal for a 31 hp surface drive with no mods or upgrades?

No. What kinda and size a boat?

beavertail 17 x 50 its got a few dents on the bottom but it is not hooked

check your neutral RPM's it should max out at 4250 ish. You should achieve at least 3800 in the water at wide open when your prop is trimmed correct. Half in/half out. If all of this is correct and you can only achieve 3250 in water you may want to check your valve lash.

^^ what he said, plus might also check to make sure throttle is getting full travel

Does that boat have em pods on that a lot of em come with? If so there's a lot of yer problem. I agree with that boat ya should be turnin bout 3,800.

Yes its got the pods. I just checked my rpms at idle and they are 1440 at idle and 4850 at wot out of the water. The prop is a powertech 19 10 pitch it measures 11 5/8" from tip to tip. I will have to do some research on how to check the valve lash im not verry motor literate but i guess i better start learning.

You mean 3850

no sir out of the water it was 4850

no bueno turn them down.

meant to type 4850 in neutral dont know if that makes a difference how do you turn them down and what should the max be set to

4850???!!!!!!

If your tach ain't jacked up, you better turn it down before ya tear it up!!! Behind the carb there's a screw that runs starboard to port. Turn that screw with the motor running to turn your wot rpm down to about 4200-4250.

Aside from that, your prop is fairly worn & needs to be replaced, but that ain't the problem you're having right now.

Pods are causing some of your issues, but not to blame entirely. There are several posts on here on how to check valve lash. Do a search & follow the directions. I'm still wondering if you're trimmed right though. What trim hole are you running in?

X2 on the valve lash and deff try an adjust what hole your running....I believe its usually the middle hole that's most people run there's in
Here's the valve setting plus some other torque specs


viewtopic.php?f=3&t=13296

tach is not messed up and it didnt sound good reved up like that watched some youtube videos valve lash seems simple enough not sure about which hole my pin is in or if i even have one i will have to look when i get home my motor is an 06 and some one made some kind of custom bracket for it before i purchased it to get the motor to sit about 8-10 inches farther back off the transom so the pods wouldnt interfeer with turning

Do a leak down test. With an air leak in the valves, you should see high rpms without a load, and in the water it sucks.

here is a pic of the bracket I spoke of I assume the pin that was mentioned is in the hole missing all of the paint there are 2 holes close together and one a little further down on the bottom with a bolt through it if thes are the right holes

IF its a stock gator tail there is no way that motor should be hitting 4850, is there anything done to the motor or is it completely stock. Rev limiter should catch it before it gets that high.

agreed, dangerous rpms for a stock motor, but even if he's hitting 4850, he should be getting more RPM's in water, so adjusting his OOW rpms will not fix his problem but will bring him out of the danger zone of tearing up his motor. His problem is else where.

the guy i bought it from said it ws stock I will adjust the governor down to about 4250 and pull the valve covers and check the lash this weekend. Im on the hunt for someone with a leak down tester that i can borrow hopefully the lash is all out of wack or something else simple I want to keep the cash ive got saved up for my reverse upgrade

Harbor Freight has a decent cheap leak down tester for about $40

I know, right?

hopefully i can find one to borrow I have only bought 2 things from harbor freight a welding machine and a grinder the welding machine never fed right and the grinder broke after 3 weeks I exchanged it and the second one is alright but no comparison to my motavo some people say some of their stuff is good but i think you get what you pay for

The power tools are garbage, but SOME of the hand tools are ok

Call around to your local auto parts stores. You may be able to rent one (usually for free).

As far as the HF stuff...if I'm buying something I'm not sure I'll use very much and we are talking a difference between a 10-20 dollar tool and a 75-100+ dollar tool, I'll give the HF tool a shot. If it lasts, then it was a good investment and would have been a waste to buy the good one, if not then I know I'm using it enough to justify buying the better one. And if you break it relatively soon after you buy it, HF will usually give you your money back or at least give you a credit to buy something else with. I buy lots of stuff there, but I have one close to work and another close to the house and it's easy to take stuff back when it don't work out.

Every one else was gone from work today so i pulled the boat up in our shop and went to work. I dont know the proper terminology but where you check your lash there was no gap at all everything was tight I set the lash on all 4 spots so that the .004 feeler gague was snug and the .006 wouldnt fit let me know if i did something wrong. I am going for a little ride this weekend to test it

Lol, how did you set them? Two at a time at 1/4 past tdc on the comp stroke or one at a time on the back side of the cam lobes?

I would not run your motor just yet...

You sure the valves were in the right position when you set em? That don't even sound normal the way you described "tight with no gap at all" on all 4

There is a video on youtube called Slingshot Valve Lash Adjustment.mp4 that i watched and folowed to set them maybe one of you guys could watch it and let me know if it is leget I used the gap settings that were posted earlier in this thread

Did you rotate the crankshaft?

as i was rotating the fly wheel there was never a time, and i checked thoroughly, that there was any gap I set them all 4 at top dead center

Check them this way:

Turn the flywheel over until the exhaust valve is all the way open, check the intake. Then turn it over until the intake is all the way open and check the exhaust.

The way the video desribed is the way briggs recommends setting the valves ( other than they recommend to go 1/4" past tdc). So that is correct. I would have to assume that you were on the wrong stroke when you set them, but if there was never any slack, that's really weird. If it had been run that way for a while, hopefully the cam and lifters aren't damaged.

Check them the way I just told you and post back!

Check them this way:

Turn the flywheel over until the exhaust valve is all the way open, check the intake. Then turn it over until the intake is all the way open and check the exhaust.

The way the video desribed is the way briggs recommends setting the valves ( other than they recommend to go 1/4" past tdc). So that is correct. I would have to assume that you were on the wrong stroke when you set them, but if there was never any slack, that's really weird. If it had been run that way for a while, hopefully the cam and lifters aren't damaged.

Check them the way I just told you and post back"

I was using a screw driver in the spark plug hole to tell when the piston got the verry top that is when i set them how will i know when the exhaust valve is completly open and vise versa using this method or elaborate a little more when i watched the video he said which was the exhaust valve on one side does it switch on the oposite side of the motor? pardon my ignorance this is my first time messing with a motor and thanks alot for all of your guidance

The exhaust valve will be on the side of the head the exhaust comes out of...intake the side the intake bolts to. Roll the motor till the exhaust valve goes all the way down then starts coming back up, then go back a little to put it back at the lowest point. With the exhaust now all the way open, check the lash on the intake. Then do the same on the intake and check the exhaust. Then move to the other side and repeat.
Sorry for the rough explanation, its a pita typing this much from my phone. there is another video that has been posted on mmt several times that shows how to set them the way I'm explaining. Search my posts for valves or lash or something along those lines. Its been posted several times.

I may have been on the wrong stroke the first time I set them I set them like cb explained and then rotated the cam a couple of times and found the spot where both of the top things were loose and the spacing was the same as when i set them so i think i did it right this time. I will test it tomorow on the water

Alright I give up. I made it worse, now im running 4200 rpms wot in neutral, 3800 wot in gear out of water, and 3100 in the water wot would a regular lawnmower shop be a good place for repairs I dont want to drive all the way to gatortail