94 200hp efi merc help

[DTA]

I bought this boat last yr and it runs great after it gets on plane.
It's a 1989 19ft winner tournament 2000. The motor is a 94 efi 200 hp merc.
It's got a 10" manual jackplate. When I bought it, it had a 3blade 26 pitch chopper prop I believe by quick silver. Had problems with it blowin out and not going anywhere. Had to slam throttle then back out then hammer it again. Local marine guys recommended that I go down to a smaller pitch. They sold me a solas, I think that's the brand, it's a 23 pitch 4 blade. With the 26p 3blade prop it runs 71 mph at 6000 rpm and still have a little throttle left. With the other prop it runs about 55 mph at about 5800 rpms and that's wot.
Neither prop setup has any hole shot. The 26 would if it didn't blow out.
The Jack plate has only been raised about a 1/2 in. Which is where these speeds were measured.
If I were to raise the motor another 1/2 to 3/4 in would I get any better of hole shot?? Also when it idles and at a no wake speed it vibrates alot. Ben checked out by a merc tech and said everything was fine. It's had new fuel pumps, has new impellers. It has a newer low water pickup gets about 15 to 20 psi at wot and app 5 at idle. Had it compression checked and all cylinders were between 118 and 120 psi. What could cause my vibration??

Some People that have had similar problems said that it could be the timing or possibly injectors. Please help and thank you

 

[Faztbullet]

Re: 94 200hp efi merc help

When I bought it, it had a 3blade 26 pitch chopper prop I believe by quick silver. Had problems with it blowin out and not going anywhere. Had to slam throttle then back out then hammer it again.

This is typical for a chopper prop as exhaust goes over & around prop, if its a little ear chopper they are worse on a heavy boat. The big ear chopper is better. The Winner you have is a copy of a Hydra-Sport VL-475 with 10 inches added.(Joe Reeves sold them the mold)and is laid up heavy.

If I were to raise the motor another 1/2 to 3/4 in would I get any better of hole shot??

No!! Lower the plate 2 inches for the 4 blade,as its slipping and likely throwing a huge rooster tail. The perfect tail is about 3-4 ft high behind engine at speed and full trim.

Also when it idles and at a no wake speed it vibrates alot.

In or out of gear?

 

[DTA]

Re: 94 200hp efi merc help

Out of gear it's not to rough but in gear it seems is when u really notice it. Give it more throttle and it clears up. So there's defininatly no trolling with this setup. The chopper prop is a big ear. And I believe it's bee worked over by a prop shop. Does it with both props. Was told that it was just the nature of this motor. I know a few people who have the 200 efi and they said they don't have a vibration. But they also said to raise my motor another 1/2 in. When fully trimmed down was told that it's to low in water. I could really care less about the speed although it's kinda nice is there another prop that would do much better??

 

[Dukedog]

Re: 94 200hp efi merc help

Do ya have it all tha way down when ya hammer it? Motor height? Set up right on this combination it should ventilate quite a bit compared to a stock gearcase and thru hub prop. Ventilation is good thing on some rigs as long as it gets a good warm up at tha first of tha day. If its excessive in your opinion, try dropping tha motor a 1/2" at a time till your happy. Load has a bearing on how much ventialtion it has also. Solas suck. A small hub trophy would be something ta try. A 25 or 23 maybe. Tempest or even a small hub Laser would be better than a Solas. Any of these props can be "surfaced" and still run very good. They are all gonna be different anyway (any two same prop same pitch). They way it sounds tha lwp is not benefical in your case. They really don't do much for a basically "stock" sub 80mph bass boat. In a lotta cases it will slow it down. It probably has solid mounts in it that produce tha vibration ya feel...............

 

[DTA]

Re: 94 200hp efi merc help

Motor is trimme all the way down on take off. I know with the solas prop if I have both gas tanks full it takes alot to get on plane and seems like the motor is working harder to turn it, I can hammer the throttle and it only revs to about 2000 rpms I can turn to wheel just a little to right or left and it starts to plane. With the chopper prop from about no wake speed when I hammer it, it will hook up, blow out, let off o. Throttle and hammer it again and it will plane out. Was told that motor is 4 1/2 inches below pad don't know what that is or how to measure that. I know that the jackplate is a 10in boss lift,manual, and has only been Adjusted once by previous owner which was about 1/2 in up. And that's as far down I can go. It's currently in the shop getting lower unit oil changed. Is the timing adjustable on this motor?
Previous owner ran amsoil sythetic 100:1 mixture. So when I got it I first asked a cert. Merc tech if that was safe? He said to a point as long as u use a oil that is designed to do that. It's got app. 450 hrs on it ran at 100:1. And he couldn't believe how good of compression it had. So I run it at 75:1. I want to k ow if this really is safe or not. Hopefully someone else has an opinoin About this. Thank you.

 

[daniel11077]

Re: 94 200hp efi merc help

i have a 2000 200hp merc efi with a 4 blade trophy plus and had the same problems. i have through prop exhaust holes in the prop. if you have these holes in the prop you may be pushing to much exhaust out of the holes like i was. I fixed mine very cheap and easy by putting 2 plugs blocking the holes in the prop. plugs are very cheap and didnt hurt my performance at all. my boat now shoots out of the hole and no more blowout on takeoff or top end. hope this helps.

 

[j_martin]

Re: 94 200hp efi merc help

Ventilation on a prop is to make it slip at slow forward speeds. A prop without a tube hub is the extreme of this. How much you want it to slip is a function of boat weight and power available, so it can be widely variable. On a high performance fishing boat, you want it to spool up to about 3000 rpm and then grab for the best hole shot. That can be tuned by making the vent holes smaller or larger.

Another factor in the hole shot is engine angle at blast off. I have found that mine goes best if I use all the negative trim available. When I first got the boat, and it was demonstrated to me, the hole shot was lousy and somewhat scary. I found that there was a minimum trim stop pin installed. When I removed that, now the negative trim of the engine kicking the heavy aft end of the boat up on top, catapults it out of the hole. I have to get on the trim right away as neg. trim will plow the bow right down into the lake at anything over 20 mph. That enabled me to raise my engine without killing the hole shot. That required a steeper prop. When I finally got it tuned up, I got almost 15% more top end than the previous owner, and a neck snapping hole shot.

The roughness at idle could be ignition, but likely is fuel. When the engine is deeper in the water, exhaust back pressure goes up, and changes tune.

I disagree about the 4 blade slipping. You'd be hard against the limiter if it was. It should bite like a pit bull at blast off if the engine is trimmed right.

hope it helps
John

 

[Dukedog]

Re: 94 200hp efi merc help

Was told that motor is 4 1/2 inches below pad don't know what that is or how to measure that.

Level tha boat. Level tha motor (at tha cavitation plate). Measure distance from CENTER OF PROP SHAFT to bottom of tha pad (boat) at center line....
Tell us what it is.................

 

[DTA]

Re: 94 200hp efi merc help

Ok. I leveled boat and motor and had someone who knew what they were doing measure so I got it right. Motor is 6 1/4 in below pad. The guy that measured has similar setup same motor and his boats about 150lbs heavier. He said his is 3" below pad and has good hole shot. Thinks problem is when in gear bow rises and transom goes down and exhaust vent tube is under water.

Could that be a cause of rough running at really low speed??

Also finally figured out the model of this motor since he previous owner had broken the top cowling and repalced it with a merc racing cowling.
It is a 200 hp xri efi. What does the xri stand for?? And since it's fuel injected do I need the primer bulb and should there be a fuel filter after the tank but before the pumps?? Gonna hopefully go out on it this weekend to do a tes and tune. The prop I am running is a quick silver #4813370-A5 26p. Cannot find the prop nut kit for this. And if any one knows abut this kind of prop and if it has any holes that can be drilled out to allow exhaust thru it?? Any feedback would be greatly appreciated.

 

[Dukedog]

Re: 94 200hp efi merc help

Thats an over tha hub chopper No holes! It uses tha everyday nut and lockin' washer but needs tha thick flat thrust washer. XRI is just a fuel injection. Yes ya need tha bulb.
Your set up is completly wrong if what your saying 'bout tha measurements and gearcase are right. Anyway you can post some pictures? If tha gearcase is what your saying, its designed to run propshaft a touch below, even or above tha pad of tha boat. Even a stock gearcase with 10' offset you can START at 3 1/4" below tha pad. Runnin' it that far below tha pad is terrible. Like said before its worthless on a sub 80 mph boat.................

 

[DTA]

Re: 94 200hp efi merc help

Thank u. I will try to get some pics posted soon. Just found another guy in this area that has the same boat with a 91 efi 200 hp 10" jackplate and stock lower unit. And yes I'm down way to much. His motor is 1 1/2 inches below pad and he has an awesome hole shot. He does run a 30p qs chopper that's been et at a prop shop here I guess. He runs 83gps. So I think I will start at
3 1/2 in below pad I don't really care about going 80 but glad that there's people out there that are willing to help us newbies in he boating world.

Will the exhaust vent tube being in the water on take off make it seem sluggish at take off?? I'm thinking that and bad gas or dirty fuel filter may also have something to do with it.