Why is my Hydrostream Valero YT with a 235 Johnson so slow??

[JWTjr.]

you can stop it from crabbing by installing a torque tab on the right rear of the skeg.

[bakerfreak]

Something just occurred to me, have you weighed the boat? My 20' Baker lost 10 mph when the wood got water logged (it still is!) Old Hydrostreams are notorious for having waterlogged core.

With all this talk about the motor, I don't think anybody mentioned the boat.

[Fullthrottleguy]

Something just occurred to me, have you weighed the boat? My 20' Baker lost 10 mph when the wood got water logged (it still is!) Old Hydrostreams are notorious for having waterlogged core.

With all this talk about the motor, I don't think anybody mentioned the boat.

I could have the boat weighed, there is a gravel yard 5 min from my house. My question is this... even if i was to go though the hassel of weighing the trailer with and without the boat to determine the weight of the boat alone and then subtract the weight of the motor and the big rear bench seat would a water logged core acutally weigh enough to be measureable? I'd have to subtract the manufactures weight (hydrostream.org lists the Valero YT as 675 lbs) from the measured weight, but with rigging and what not would i acutally be able to determine anything? I would expect the boat to be faster than this even with 4 people aboard (which is also what its rated for); I`ve been running my tests with two people of moderate weight (175lbs each) and it`s a complete dog. Even if it picked up another 350lbs in water logging (equivelant to two more people) - should go better than this. 350lbs is around 42 us gallons of water - if it soaked up that much I think my sandals and lifejackets would be floating around on the floor the boat.

Thoughts ?

Our family boat for the past 20 years was/is still a `81 Canadian version of the Checkmate MX-15, branded a panther up here. With a `78 Merc 115 I-6 tower of power, I was running it with a 26 pitch prop not unlike this one up until i sold that prop this year, with the motor bolted to the transom and it would launch better than this thing. I think its got to be the motor; I mean were comparing a 115 to a 235 here!!!

P.S. For reference I believe the MX-15`s weigh in at about 100 lbs less than the Valero YT`s.

Keep the thoughts comming guys, I`m keeping my fingers crossed that when the new jets arrive for the carbs it will wake this old beast up!
Dave.

[Fullthrottleguy]

you can stop it from crabbing by installing a torque tab on the right rear of the skeg.

Ok thanks for the info; I will be installing one of these (gonna make one and weld it on) as well as a bob`s nose cone over the winter to make the boat run better at speed and allow me to jack the engine way up in the spring

[perfmarine1]

Keep in mind this is a tunnel type boat that are always harder to get on plane than a v bottom cuz of the added drag and floats lower in the water although not a true tunnel ,it will make some difference.

[Fullthrottleguy]

So as i wait for my parts to arrive I can't help but read and research all I can about this hull; and about the build quality issues that have been mentioned numerous times. Engine issues aside I want to make sure this boat is decently sound before I go investing alot of time, money and love into it - and hopefully go ripping accross the lake at 80MPH one day. I crawled under the boat after work today to try to confrim the integrety of the hull; i brought along a little carpentry hammer and started tapping. The pad sounds very solid, like tapping on a 2x6 board, it has a consistant sound everywhere for the first 5' - after that it sounds a bit hollow. The transom also sounds solid and doesn't move when i bounce on the motor. My question is: is it common for the pad 5' and greater away from the transom to sound less dense? Does the core go all the way up to the front of the boat? To me it sounds the same as the "V'd" parts of the hull away from the horizontal surfaces when i tap on it. I should also mention that this area 5' and greater away from the transom can flex slightly if i push really hard with my thumb, where as the rear part of the pad won't even budge if i jack the boat up off the trailer in that area. Furthermore, there are some horizontal stress cracks along the pad in some areas, I'm not sure if these are old or new. I suspect that the floor has been replaced as i think i can see a join line a few inches off the transom and the floor is very solid everywhere; the core could have been done too - but im not sure.

[pointer]

Where abouts in Ontario are you? John Spaeth knows these boats very well, he's in Ontario... .
I think JWTjr is giving you good advice, be worth having a second set of eyes look at the hull, imo.

pointer

[Fullthrottleguy]

Where abouts in Ontario are you? John Spaeth knows these boats very well, he's in Ontario... .
I think JWTjr is giving you good advice, be worth having a second set of eyes look at the hull, imo.

pointer

I'm about an hour away from John's shop; being new to hydrostreams I was just recently made aware of how close I am to an expert in boat building who has a lot of the orginal moulds. I've also heard that alot of the old checkmate and challenger moulds are in storage at Quinns marina about 45 min from me; it's good to be in the GTA. I'm going to give Mr. Spaeth a call in the next week or so and see if he would mind taking a few min to look over my boat and give his opinion on its' integrety. Thanks for the advice.

[JWTjr.]

it has a consistant sound everywhere for the first 5' - after that it sounds a bit hollow. The transom also sounds solid and doesn't move when i bounce on the motor. My question is: is it common for the pad 5' and greater away from the transom to sound less dense? Does the core go all the way up to the front of the boat? To me it sounds the same as the "V'd" parts of the hull away from the horizontal surfaces when i tap on it. I should also mention that this area 5' and greater away from the transom can flex slightly if i push really hard with my thumb, where as the rear part of the pad won't even budge if i jack the boat up off the trailer in that area. Furthermore, there are some horizontal stress cracks along the pad in some areas, I'm not sure if these are old or new.

Core is bad & has delaminated from the outer layer of glass.

John

[Lockjaw]

I can add a little to this. I had a bassboat that was waterlogged, and it was a total pig. It had a 1200 pound hull, was rated for a 175, I put a 96 200 Venom on it, and it wouldn't fall out of a tree. It should have run well into the 70's, the best I ever saw was 65 on the speedo. Even with a 9.5 in jack plate it didn't lift, with a raker prop no less. I finally got irritated trying to get it to run, and put a 23 p gade on it. The boat wouldn't run 60 in the summer, it was pitiful. It was a basshawk, every person I ever talked to said the 18 foot ones would fly. 1200 pound hull, 220 hp at the prop, it should have run like the wind.

If your boat isn't doing what it should and your motor is in good condition, then you either have an issue with water intrusion, or what John described, or both.

[Fullthrottleguy]

Ok guys,
I had the boat up to a freind's cottage this weekend to test it out... the results were very good.
Since the last time i ran it i took the bubble back exhaust cover off to check for blockage or any other possible issues; I notcied that like the plugs the exhaust passageways seems quite wet with fuel. On the advice given by perfmarine1 I replaced all the jets, and everything else replacable in the carbs. I used a drill bit to gently compare the size of the old and new jets (keep in mind they had the same part number) and the old jets were likely a few thou bigger in diameter. The most noticable difference was the size of the old seat for the float needle, the size of that orifice was quite a big bigger on the old part in comparison to the new seat - very odd. I also rebuilt my old lower unit, which has a better skeg and drilled exhaust and took off my spare from the other 235 (that was seen in the pics).

Results??

My top speed previously was 55 MPH @ 4900 RPM and sluggish the whole way.

Now?

72 MPH @ 6000 RPM!!! The throttle was snappy and the boat felt great!
JWTjr - With the better lower unit there must have also been less crabbing as there was no prop cavitation; unlike the last time.
Keeping in mind tha the propshaft is about 3" below the pad and I'm running a 26 pitch ski prop I think that speed quite impressive Looks like it will be time for a chopper prop next spring... I'd love to hit 80. With the better lower unit there must have also been less crabbing as there was no prop cavitation.

Thanks for the help everyone; expect a new thread sometime soon for setup tips and prop selection to get me into the 80's

[capnzee]

I would think that the gent who suggested the test wheel is on the right track. You have to isolate the problem starting with the engine. Either find some one with an outboard type "dyno" where you can bring the engine up to "peak" power or at the very least a test wheel with a known rpm range you should be able to obtain at WOT. Once you have the engine sorted out, you can go to work on the boat. If you find out the boat bottom is "warped" you can take a good look at the bunks on your trailer, they may have caused the bottom of your boat to "go away".

[EMDSAPMGR]

The factory put two different heads on the 235's in 1981. The "H" suffix models got the high compression 638/639 heads. All others got the 124/125 heads. The compression will jump 10-15 lbs with the 638/639 heads. The "H" suffix engines also ran slightly different carb jets sizes. That should make a lot of difference in performance.

[Fullthrottleguy]

Now that spring is here I'd like to update you all on this boat. Before the season ended last year I purchased a 28 A5 chopper and got it upto 76 MPH GPS @ 6200 RPM. There have been many suggestions that the core was bad - I want you to know that I've cut the floor out and opened up the core. It is completely rotten! JTWjr I you called this right away - I've listened and I've just started my rebuild process. I'm doing the rebuild thread here: http://www.fastboatscanada.com/vBulletin/showthread.php?t=8280

The boat has hollow fiberglass stringers, due to the flexing of the core they were partially seperated from the hull. I won't have a problem getting them out in once piece. Should I be reusing these or making wood ones? I've heard Hydrostream used both techniquies but I was wondering what you'd reccomend adopting. These hollow structures seem much lighter then their wood counterparts - I just want to confirm that this is a worthy practice and not just an 80's method of building boats fast and/or cheap.

[bulldogdaddy]

fulllthrottle,just saw your post and glad to see you have got the mottor running well now,i am waiting on a set of 72d"s for my 87,225.took the airbox off by one guy who told me you need more airflow,and then after i waisted a year decided to have frosrtman ask me where the airbox was!but hey its a love of labor,and hope you are ready to go thru the process of doing the hydrostream recore,there is alot of projects on here over the years.and for what your going to put into it,you better want to keep it because you will not get the money you put into it back.and also as stringers go,ask on the fiberglass section but you might want to look into composite ones,lighter,i dont think you can use them for a core but i dont know.good luck and always post pics of the progress