still same problem? or something different???

[89basscat]

Ok... you guys helped me out alot with a problem i was having last year.. i have an 1989 Johnson GT200 that is on a 1989 Basscat Pantera II, 6"CMC Jackplate, propshaft 3 1/4" below the pad. I had a problem with the top end.. no matter what prop i threw on the boat i could not get the rpm's above like 4400-4500. I took it to a local shop after finding a half decent shop in my area. He found a bunch of small things that contributed to a bigger problem such as loose carb bolts, a fouled out plug and some other small things. motor runs much better now i can get about 5400 out of it... however i still think there is a problem there.. I bought a 25 tempest off ebay and sent it to mark croxton to get worked, he called me and said the blades were 1" shorter than what they should have been. So i bought a brand new tempest... whatever i do i can not get this boat to plane out with this prop.. its weird... if i set the pvs plugs to vent at 3500rpms like they say you should when it starts to lay over it cavs, or even beforeit lays over sometimes. the only way i can get this thing on plane is to load the prop up with like 1 solid and 2 small... and then the holeshot is about 20 seconds. horrible. the max rpms i got out of this prop was 5000 and 58mph and mark said this motor shouldbe able to turn that prop 5800-6000 easy. so mark and i are still puzzled and he sends me a 23p shooter or something.. a 4 blade anyway. This prop i can turn 5400rpms 56mph and this is the puzzling part... if im running a 25tempest 5000 that 23 shoudl put the rpms through the roof... with all these props i have very littlebow lift also... i hope someone can help.... im really getting frustrated with this motor.. if it wasnt so far and had the time id take it to rusty because then i know it would be checked the right wayl.... but im in pennsylvania and hes in tn... its hard to leave my job for that long..


Thanks to all that are helping

Jim

[1993392]

Not and expert but it sure sounds like it's not hitting on al cyls. Have a look at your plugs. Do they all look the same? Are your carbs opening all the way ? How's the compression ? All cyls should be within 10% of each other.

Sounds like what mine was doing when the power pack went south.

[overdrivecb]

can you feel a miss when trying to plane you may noat feel it when it is planed off

[89basscat]

yea... compression showed good, but earlier this year i can tell you that one plug was fouled out... i changed them all... the only thing we didnt do when i had it looked at earlier this year is the WOT timing and thats because it was frigid cold when we did everything.....oh and the carbs did open all the way... it almost seems to me that there isnt enough horsepower there to turn the prop and i have to vent it too much so therefore its causing the prop to cav...


Thanks again,

Jim

[ChampioNman]

OK here is just something wild that I came across with your M.Y. pull the flywheel and look for scuffing on the bottom of the wheel or top of the stator. If you see that you need to pull the head and check the bottom bearing bolts. This one drove me crazy for a while and when I pulled the head I found 2 bolts sheared and the rest finger tight. Pulled the bearing and carrier, removed the shear bolts, tapped out installed and torqued to spec and got back to normal.

[overdrivecb]

i had a very similar problim on my 92 200gt i replaced the whole ignition system ...pp stator rectfier and timer only to find out that the shift assist switch was sticking and making it act very stupid .

i am no tech but it maybe something easy to check before you spend any money

pull it off and mash the button a few times and maybe try running without it in the bracket

caution i am no tech and i dont know if this will have negative effects on your drive train
mine will not shift back into nuetral with the engine running with the switch out of the bracket ( you have to turn the key off then go to nuetral)but it ran good so i replaced the switch