1999 ZX202C what do ya think??

[BASSNAM2PM]

I recently purchased a 99 ZX202C with a 200 Yamaha EFI on it,I can't tell you what rpm's I'm spinning cuz the tach didn't work but I replaced it and will find out this weekend. It has a 3 blade 25M prop that appears to be in good shape,I added a torque plate after reading about them here and it eliminated the huge torque steer it had...thank you thank you thank you! I apparently can over trim a bit because I drop a mph on gps when having it trimmed out. I'm also not sure about water pressure at full plane the pressure gauge wasn't working either I replaced it also.I checked to make sure the carbs were opening all the way and they are.The boat get's up on plane fast and doesn't throw a rooster tail any higher than the engine cowl. Anyway,I was running about 3/8's full of fuel in each tank with two people but the livewell shut offs didn't seal so they were both about half full or so (I put plugs in them now) and I was only running 61-62 mph on gps. Is this all I can expect out of this rig? I had a 1992 Astro 185FDX with a 200 PRO V on it ,3 blade Lazer 2 prop and no jackplate and could pull 64 tournament loaded with two people. I guess I was really hopeing for more top end speed with the new rig. What do you think?


Modified by BASSNAM2PM at 8:42 PM 6/8/2006

[Skeeter Jay]

I would think that boat should be pushing 70, something doesnt sound right. Would probably help diagnose your problem if we knew your RPM's, water pressure and pad height.

[Bass Junkie]

I agree, that rig should run faster than 62mph. When you get the tach and pressure gauge working post back up here with all your info and between the lot of us we will get you fixed up. Right now with the limited info it's pretty much impossible to figure out. In the meantime measure how far the center of your propshaft is below the pad so you have that info along with the RPMs and water pressure when you repost.

[gleninaz]

I have the same rig only a 1998. I raised the motor and am getting 68.5gps with two fat guys and full 60 gallons of fuel. Same prop and at wot I am still pumping 15 psi.

[Charger]

Same here, 98 model with 200 pushes 70 on gps with 25M prop.

[BASSNAM2PM]

Okay,fished a tourny this morning 2 people empty livewells little less than half full fuel in each tank new spark plugs. Center of prop shaft is 23/4" below pad. Tach read 5500 rpm's and about 22 lbs. water pressure at wot and 64 was best I could do. Everyone in club agrees it should be a 70mph boat can't figure out where that extra 5mph's at One guy said to drop the engine some and try a 25T Tempest prop,what you all think?

[EL Skeeter]

Your excess gear weight will slow you down.Carry only what you REALLY need.

[JohnPZX]

I have a 99 ZX202 as well. Forget the Tempest and any other prop. That 25m (blueprinted) is the prop you want. I spent a good deal of money on others to find that out. Once that prop has been worked you will be able to raise the motor and still have sufficient bite. I was running 70-71 with a stock motor after the prop was worked and I sanded the pad. After engine mods and low water pick-up I am running 77+ (73-74 loaded).

[BASSNAM2PM]

I'm aware of the weight issue that's why I run only as much fuel as needed and keep the front light as possible. I've gathered that raising the engine will also raise the rpm's and I'm already running 5500,don't know when the rev limiter kicks in but I beleive that this motor is supposed to run at 5400 ? Would the torque tab I've added rob that speed?

[gleninaz]

You are just where I started. Loosen up the jackplate and raise the motor an inch then try it out and see what you get. If it is too much then drop it a quarter inch at the ramp and try it again. You are too low on the plate.

[5littleones]

I agree, sounds like your motor is too high and you're lugging the engine!

You need to raise that motor 1/4 inch at a time till your water pressure drops (look at iz1t when you're turning) ... should get in the neighborhood of 15psi ... drop below that is danger!! Once you get to a point where the water pressure starts to drop, raise the motor back 1/4 inch. That's about where you motor should sit.

If you're still not getting the speed. Send the prop in for a blueprint and balance. Mark Croxton on the prop board does a good job. I got close to 4MPH after he did mine!!

[5 keepers]

JohnPZX is dead on with the propeller with this rig.

[BASSNAM2PM]

Well I filed all the small imperfections smooth on the prop and raised the motor a 1/4".I'll see what happens this Saturday

[Bass Junkie]

I know you hate to hear this now but you should NEVER file a prop. Files have carbide in them and it will embed itself in the steel making it harder to weld later if need be. If you have any really small burrs you can use sandpaper to smooth the edges. A Dremel tool with a felt tip and some polishing compound works really well too.

[BASSNAM2PM]

I never would have thought moving the motor a measly 1/4 inch would have much of an effect but my water pressure went down from around 20lbs. to only 10 and speed fell from 64 to 61 rpm's stayed the same.I'm going to drop the motor a 1/4 inch below where I started and see what that does but I'm thinkin the rpm's are going to drop too low.At any rate I'm not comftorable running that low of water pressure.Again,does anyone think a torque tab would rob several miles of top speed?

[JohnPZX]

Something does not seem right to me. You really should not have any problem running that rig at 2.5 inches below pad. Then to loose half your water pressure and your rpm's to stay the same. Very carefully double check your pad to center of cone height. Maybe your tach and be sure you don't have any junk blocking your water pick-ups. You mentioned filing your prop - how bad was it to begin with? Seems to me if all is well I would grab another 25m and run it (back at your original setting) and see if there is any difference. At least that will give you a starting point to find the problem. I have seen props that are say a 25 pitch - and when they are measured before blueprinting every blade was a different pitch. There are props that are just plain born bad.

[BASSNAM2PM]

The dings on the prop really weren't bad at all. I leveled the boat on the trailer and measured from pad to floor then put a level on the cavitation plate and measured from center of the prop hub bolt to floor and subtracted the two figures to come up with 2 3/4" difference. I didn't measure this way after moving the motor on the jackplate however I marked the place it was at and moved the motor up a quarter of an inch. It's possible the intake may had a little debris in it but the motor was peeing strong. The water pressure reading was quite erratic going from around 7 to 14 lbs. but it was choppy on the water also. Partner noted he could see the top of the cavitation plate when we were running hard. Ideally it would be nice to experiment under the same conditions/day to get a real accurate effect/result but half the time on the water this year has been during tournaments. I'm leaning towards suspecting the prop also I've seen what a difference they can make on my two prior bass boats but everyone seems to agree the 25M is THE prop for this rig. If I don't make any further progress going down with the motor I'll have to bring it down to a guy that has worked my other boats up to speed. Only bummer is besides the expense it's a 3 hour round trip and the guy has kind of an ego problem cuz he races boats,was hopeing to figure this one out on my own.

[gleninaz]

I think going down a quarter inch will find the sweet spot. Mine was also too high above that. Good luck.

[BASSNAM2PM]

Lowered the motor a 1/4 inch below where I started,plenty of water pressure predictably ,rpm's dropped to 5400 top speed was 61.Couldn't seem to over trim though,gonna leave the motor where it's at and try trim extenders. If that don't work I'll havta make the 3 hour round trip twice and get help. Granted 64mph is fast enough the only time I care to go faster is during blast offs but I'd like this boat to be performing at it's maximum. I'll report back when I get to try it again with the extenders but I really doubt if I'm gonna be able to reach the 69mph mark that others are claiming with their 202's.

[gleninaz]

Something isn't right in your setup. I am pushing 5800 with good pressure and much better speed. It sounds like your motor is too low. Maybe you have a bad prop. Can you borrow another 25m to try? Good luck.