changed the prop and killed the boat

[Booger]

18' Stratos Johnson GT200 just replaced my 14 1/2 x 22 Raker with a 14 1/2x24 Raker because my top speed was barely 50mph wot. Went out this morning to try it and top end is good but my fishing buddy had to move to the front of the boat before it would plane. Motor is bogging very bad, have to keep pushing the key primer just to get it to run to get on plane so it won't die. If you hit the throttle with out working the key switch primer it will just die. Once it gets on plane it runs perfect though. I had the carbs built a few weeks ago and new plugs. Does it sound like a carb issue? The shop that did the work said it may need rejetted when I change props. Is there anything I can check before I go back to the shop or should I leave it alone and just fight it until he looks at it again. Thanks.

 

[wrechin2]

The ONLY time you have to re-jet over a prop change is for a race application because that can cause a engine to burn down very quickly because you are running on the edge. A stock fishing engine is fairly rich to sqelch the cylinders for operation under a vast array of conditions and loads. 50MPH out of a 200GT on a 18' sounds like a sick engine or issue with the igntion or carbs. Make sure all 6 butterflys are operating. I had on that the linkage on the bottom had came loose and was running on 5 cylinders. I have delt with them on 20' boats that would run in the mid 60's. Have you had a leakage test performed to check the true health of the engine?? You may be looking in the wrong direction. I done one yesterday on a 225 and it was a sick puppy. It failed the leakage test but passed a compression test. Compression really doesn't tell you squat but what octane to run. I can show you in the factory manual where it tells you basicly if it has good compression but performs poorly you can still have mechanical issues. I have copied it and will post it when I find it. A load test will see if a ignition coil is breaking down under a load.

Do you still have the old prop to see what it does with the 22?

Is that GPS Speed?

What RPM are you turning??

 

[wrechin2]

here ya go. Please note the part I have outlined. It reallys should read OR performs poorly. </p>

</p>

</p>

 

[Booger]

Compression and I think leakage test was done. 54mph was with GPS at 7000 rpm's. I forgot the GPS today when I tested it but the rpm's never got above 6000 with the 24p prop and seemed to be moving much faster, I will take my GPS later today or in the morning. It ran fine and had a great holeshot with the 22 just no top end.

 

[wrechin2]

Something doesn't add up. There are 2 possibilities for a rev limiter on a 200GT and one is 6200 and the other is 6700 so it couln't truely be turning 7K without special race packs. There isn't going to be a 1,000 RPM difference between a 22 raker and a 24 raker. At 7K and 54 MPH that is 34% slip and even with the same speed at 6K is 22%. JME....

 

[Booger]

OK I swapped fishing buddies for another run this evening. I traded a 300lb guy for my 100lb son and it comes out of the hole better but I think it should do more. It ran 55mph on GPS at 6400 rpm's. So I gained 1 mph and went down 600 rpm's. Surely a 200 on an 18' boat should do more than 55mph but I don't know.

 

[wrechin2]

Yes, it should do a lot better than that. IME.......

Given the pitch, gear ratio, rpm and speed somthing doesn't add up. I suspect the tach is incorrect. I have seen those engines push a Stratos 201pro into the low 60's with no problem. Just my thoughts...

 

[wrechin2]

Had a friend tell me if you want to try his 23 and 25 renegade 4 blade, you can call him. Pm me and I will pass along his name/number.

 

[M GO BLUE]

That thing should run easily in the low 60's at 5800...That engine should turn a 25/26" prop EASILY....If you gotta keep priming it to twist the R's you need to get on plane, something is wrong. Have you verified the syncro of the timer-base/carb linkage? That boat shouldn't weigh anymore than 1400-1500 lbs, if I remember correctly...

 

[racinwithrex]

Changing MY fishing partner, I went from catching 2 fish to 8, one weighing a little over 4 lbs. Told you that Roadbed would pay off after the milfoil spray...lol..lol.. I still don't think it's the prop problem as much as a "Carb issue" or electrical but what do I know. Oh and it's 282 1/2 lbs. partner.... "Thank You"!

 

[wrechin2]

You are NOT right in the head Rex!!!!!!!!!!!!LOL!!!! emoToast

 

[Guest]

ok first off this motor is not a GT 200 it is an early model crossflow 200 with three 2 bbl carbs not the standard GT setup with six plastic carbs like they have on later model loopers . second we have no idea what the previous owner has had done to the engine. this is a small bore 200 and it may not produce the power the later models do even the early model loopers pre 93 finger port motors were pigs coming out off the hole we had the motor running pretty good with the smaller prop it may be that this motor does not have enough low end torgue to spin a 24 pitch prop. after carb rebuild hole shot was good untill motor got hot we may even have a tstat problem . we just need to spend alittle more time on the motor to fine tune but he may have to settle for the 22 pitch prop after carb rebuild when motor got hot he could bump primer solenoid and motor would come out of the hole. james you know a 23 or 25 shooter might work on this setup if we can find one.

 

[wrechin2]

<font color="#ff0033">watermark - 6/21/2010 11:30 AM ok first off this motor is not a GT 200 it is an early model crossflow 200</font> .

</p>

That makes a BIG difference!</p>

The renegade is a better prop in my opinion. The stock 200 X-flow does NOT have bottom end torque to do anything with and do very well with 4 blade props that allow them to spool up or a over the hub prop like a chopper. I built a modified 200 and done stuff to it to make the lower end stronger and ended up with a 22 big ear chopper and would hit the 5800 limiter. We now have the unlimited packs on it and need to deal with the set up. </p>

If it has lost power after the overheat, it may have damaged a cylinder, caused the ringto loose thier tensile,or egged the cylinders. The XP 150 I recently done had great compression (87-93 PSI) but failed the leakage test and we found 3 of the pistons had the 2nd rings stuck from carbon and all the cylinders were egged. It had been overheated at one time. </p>

My guy read this andsaid he would be willing to hook up with him and let him try his props. </p>

 

[Guest]

James I dont think it overheated I think we may have a tstat issue letting the motor run hotter than normal operating temp and causing a heatsoke issue or may not have tstats at all some people dont think they need them if they only knew.he says that it runs good first think in the morning with the 22 pitch prop but gets worse when the motor warms up. he can bump primer and it comes out off hole good.

 

[Booger]

watermark I assume you are the feller working on my boat if so I will be there first thing in the morning with it as I have no doubt you will get it straightened out. Second I assumed it was a GT200 cause that is what the sticker said. With the 24p prop it also comes out of the hole good when cold in the morning. wrechin2 tell your buddy thanks for the offer.

 

[Booger]

P.S. Hey Rex I'm gonna stick with 300, and I think the reason you only caught 2 was cause I woke you up too early emoPoke

 

[wrechin2]

Ethanol does create more heat soak issues due to the lower boiling point. Try trimming up when fishing and see if that helps. I had a 150 60* that wouldn't start after a heat soak. The starter was dragging badly. I replaced the impeller and issue went away. It was close to overheating but wasn't and that was the only issue. Just a thought.

 

[Fishingron]

For what's it's worth guys. I have an 18ft Stratos (288) with a Johnson 150 with a 25 pitch Renagade. Hole shot is good, top end in the low to mid 60's at 5600rpm even with my 225lb brother on board. Hitting the primer to get it on plane tell me there is something going on here and it's not the prop.

 

[wrechin2]

Hitting the primer does indicate a problem.

Apple to Apples on engines.....Even though you have a 150, your engine is a larger cubic inch engine and has more torque than this X-flow 200. HP is a very crude way to measure a engine's output. Some engine manufactures of 4 strokes are actually starting to rate their engines by Torque and not HP because of this reason. Take a Chevy 350 making 400HP @7,000 rpm and a Chevy 454 making 400HP @4,000 RPM for example. They both make 400HP but the 454 would be a brute when it comes to torque from the large cubic inches. Put them both in a light weight race care and the 350 will do better at short distance than the 454. Now put them in a dump truck with 20 tons of dirt and the 350 wouldn't get it to move and the 454 wouldn't have any trouble with it. Even though these examples are 4 strokes, it is the same priciple. That is why you see 3.3L 200HP now because they need more torque to move the heavier boats. You have less HP but more torque than he does. Torque is what actually does the work.

 

[Booger]

wrechin2 - 6/22/2010 1:11 AM

Ethanol does create more heat soak issues due to the lower boiling point. Try trimming up when fishing and see if that helps. I had a 150 60* that wouldn't start after a heat soak. The starter was dragging badly. I replaced the impeller and issue went away. It was close to overheating but wasn't and that was the only issue. Just a thought.

I always go to stations that say "No Ethanol" and I do trim the motor up while fishing. Boat is back in the shop and I think Andy will figure it out. He seemed to have some good ideas about what might be going on.