HELP - RPM loss after replacement motor....96 XP???????

Last year I could hit 7k rpms with my 96 XP with a few mods, but I also lost my motor due to a faulty crank. Now I have a new motor...newly rebuilt, and I can not hit over 6700 rpm's? The same carb set up, same pump, impeller combo; everything is the same.....except for the motor. What could cause this, the plugs look to read fine, the tach holds steady...I just cant for the life of me find my other 300 rpms. I lost my motor and got a complete SBT motor....there is over 15 hours on this motor now...it should be broke in by now, Where to turn?

I'll print this one out for my customers to read.

Laszlo,

I didn't realize you had any customers anymore.

Greg SBT

Huh? Why do you say that? Couldn't think of anything else? Actually, I have a shop full of boats (stacked 4 high) to work on and more scheduled to come in.

Then it sounds like for the sake of your customers, you should get back to work and mind your own business.

LOL....actually, I 'am' taking care of my customers, and it is 100% my business. Keeping abreast of issues concerning parts and rebuilds is my duty to my customers. By compiling all the information I can and supplying that to my customers helps them to make an informed decision.

I don't have anything against your end product except for the reduced compression as a result of remachining heads. I have one at my shop that I consider to be useless as an OEM replacement now. And I have had numerous customers inquire about SBT rebuilds. If that is what they desire, I tell them to remove their motor, bring me the parts, and I will rebuild it for the same price they would end up paying to get one from SBT...with the same warranty...but with all OEM components with the exception of the conn rods. And no loss of compression etc. Once they see all the issues, guess which option they choose. Granted there are some people here locally that use SBT rebuilds...I just haven't gotten to them yet.

Everyone here knows George is full of it. I would Go to a reputable house for work not to a self important jackass. Here He is known as the Tiny Yapper, or the Newsgroup Fool. Giz and Bill Oneal , Laslo and many others are available to you.

We could use more here huh?

Kris, how is the weather there right now compared to last year? Is is cooler with less humidity? If so, try richening up your carbs 1/8 - 1/4 turn to see if that helps any.

Kris - check your water regulator. When they start to fail the water flow to the pipe is not completely shut off at top RPM and it usually decreases top speed and RPM. You can easily test it by clamping off the injection line from the water regulator (RAVE valve looking device on your waterbox) to the stinger pipe. Then ride it WOT and see if your RPMs return. If they do then replace your water regulator assembly and you're all set.

Sounds like the rotary valve is off a couple degrees. Brian