1990 GT 200 at WOT only getting 4600 RPM's-Please help!

1990 GT 200 Looper, 1990 Stratos 201XL. Last year this boat would scream and ran great at about 5700-5800 RPM's. I have recently had a new timer base installed, a new power module pack, a new ignition module but still doing the same thing as it has been doing and these items were all installed new by the boat mechanic because he said that they were bad, this was over three different trips to him for the same low RPM problem. I can't understand why I am still only getting 4600 RPM's at WOT. It appears that all these new parts didn't help at all however they may have been truly going out or going bad I'm not sure but I still have my problem.

Please let me know what you guys think I should check next.

Re: 1990 GT 200 at WOT only getting 4600 RPM's-Please help!

I've got the same engine and have done all my own work on it since I purchased it on ebay (plus I slept in a Holiday Inn last year). I'm wondering what you're calling a "power module pack" and "ignition module". Is that what the mechanic told you? (The major ignition components are the timer base, stator, power pack, rectifier/regulator, and coils.) Are you certain he actually changed anything?

To start with, do a compression check. Then purchase a 10$ variable gap spark tester from an auto parts store and make sure you've got good spark on all cylinders (set spark tester gap at 7/16"). Do all the spark plugs look the same? Has anything at all changed with the hull or prop?

Also, a factory service manual is a great investment even if you don't plan on doing all your own work (but if you get one you'll realize that you're perfectly capable of doing a lot of things you'd otherwise pay to have done).

Re: 1990 GT 200 at WOT only getting 4600 RPM's-Please help!

Metric, I am 100% certain he changed the items out to new items because I had him give me the box the new item came in and also had him give me all my old parts each time. Now as far at what he installed it was a timer base (brand new), the power pack (Brand new), and the rectifier/regulator (Brand new).
The only thing that has changed which I keep questioning in the back of my mind is I had new carpet and new upholstery/interior installed at the end of last season....when he remounted my hotfoot he set it more at about the 1:00 position (otherwords sitting in my seat my foot when in the hotfoot is pointing more at the 1:00 position) and the throttle cable is somewhat bending around at a fairly sharp turn feeding to the hotfoot coming out beside my seat on my right hand side of course...before that it was mounting more at about the 10:00 to 11:00 position so that the throttle cable followed perfectly out of the hotfoot into the side of the boat along the side of my seat back to the engine so to speak.....I'm beginning to wonder if perhaps I am NOT getting full throttle plus when I press the gas/hotfoot down for WOT it bottoms out on the backboard under my console....it hits the back wall behind the hotfoot.......But when I pulled the breather cover off the carbs it appearded that they were opening all the way but when I got my wife to sit in the seat and push the pedal down WOT and I was back by the engine I could take my hand and move the throttle linkage and they (the gold carbeurator baffles) would open up alot more going past the straight open point. I hope I am explaining this to where you understand what I am saying. When the carbs open the baffle moves from the close position to where they are then straight out where you are looking at the then side of them in to the carb openings. Like a flat coin and then looking at the edge of the coin. Anyway as stated when she was giving it WOT I could take my hand and manually move the throttle linkage and they seem to open up alot more going slightly past the full open position........Question is do you think I am getting full throttle or could my hot foot sitting in the position it currently is in is maybe only giving me like 3/4 throttle or possibly even less?????

Also I have been running mostly ethanol gas because thats about all you can buy around here now however I do occasionally pour a little seafoam into the tanks but only a little about every 5th fill up if even that much may be more like every 8 fill ups.

Right before the end of last season which is when I took it to get the carpet and seats done and he kept it about 4 months since getting it back seems to be when it stopped running so fast and running at top rpm's.

I am pretty mechanically inclined and can almost do anything on a car engine that I set my mind to.....are these carbs and the carb jets and components etc something that you recommend I try to clean/service and if so is this something that I can do myself????

Thanks for all your help METRIC.

TODD

Re: 1990 GT 200 at WOT only getting 4600 RPM's-Please help!

When the throttle is pressed all the way the butterflies should be facing exactly fore-aft in relation to the engine. Don't mess with the linkages, just have someone push the throttle all the way down and look at the butterflies. If that's not the problem then check compression, spark, and after that you might be justified in getting carb rebuild kits (compression on this engine should be around 80 to 90).

Running E10 fuel shouldn't have anything to do with it, these engines were designed to run on that, but everyone here recommends to use fuel treatment all the time as well as a good separator/filter (I do and haven't had any problems).