Hmmmmm...seems like you should be able to turn at least in excess of 8000-8500 rpm with that prop. DON'T try to turn 16 grand like some folks will....."BOOM"

Is this a new engine? Not uncommon for a new engine to be a bit sensitive on the high end setting. If it's new...allow it some time and operate the engine as per the supplied instructions.

If not, some areas you may investigate are:

* All screws (backplate, carb, head, plug) properly tightened.

* Valve settings. (a valve not opening/closing completely will have an adverse effect on engine performance)

* Double check the fuel system. Pinholes in the fuel line, leaky fuel filters (they s*ck in this regard), incorrect fuel tank positioning can all drive you bonkers!

* Fresh Fuel. Who knows...a little moisture absorbed in your fuel pretty much ruins it. Crack open a fresh gallon.

Lastly...check your Tach. Make sure it's set for "2 blade" and to verify it's accuracy...aim it at a fluorescent light. It should read 3600RPM.

Good Luck! Let us know how you make out.

Oh...one more thing...

Did this loss of power occur suddenly, or was it gradual over time?

If it's been a slow process....wear may be a factor.

Try the fuel, and check the other stuff. Good Luck!

alright. check the stuff I mentioned earlier. Sounds like something came loose, got a pinhole, etc,et al. Again, the fuel could be bad too...if the motor was fine last weekend, and this weekend it's way off in left field...

Just check the other stuff thoroughly! Report back with your findings.

Did it by any chance back-fire on you lately, like on or around the time of the power loss. As said in an earlier post I had a new magnum .91 backfire. The result being power loss(RPM) and eventually a broken connecting rod at the crank journal. You may want to pull the back plate off and check for an egg shaped connecting rod end, if you didn't figure it out yet. I was swinging a 14-6 prop almost 9800 before the back-fire and after only 7500.

Ya know....an "egg shaped" con rod is also caused by creaming the engine with an electric starter against a hydraulic lock....

Seeing a surprising number of "con rod" problems with Saito engines on this board, and I know those engines to be as trouble free as you could expect. Hmmmmmmmmm....

Over-revving and electric starters are evil.




"Former Northern Michigander...."

That is a very good point, you are correct.

Stripped threads!? Did this just happen or are you thinking that this is the cause of the power loss? Loss of compression would certainly put the hurt on the power output.

Going forward...be careful tightening the plug! A good "snug" with the plug wrench (finger pressure...not bicep) is all it takes. A small screwdriver style "nut driver" is good for this...limits the amount of force you can apply.

Also...when installing a plug, it's easy to get cross threaded. I've found that a 1 or 2" piece of fuel tubing slipped over the electrode on the plug makes a handy installation tool. The plug is gripped by the fuel tubing making it easier to install it into the often recessed plug hole. In this manner, it is not possible to damage the threads. Either the plug installs easily or...the tubing simply slips. When it's in...snug it with the wrench/driver and that's it.

Good Luck!

NO on the perry carb thing.

If you have a fuel pressure issue, it's not the carbs fault.

Try positioning the fuel tank correctly...ie: tank centerline level with the needle valve. A little (1/8" -1/4") above or below is OK.

This should be detailed in the engine instructions...again READ THE INSTRUCTIONS. The engine cannot be expected to run correctly if the tank is siphoning fuel into the carb, or...the engine is trying to pull fuel uphill.


Larry...put your checkbook away! You do NOT NOT NOT NOT NOT need a new carb.

Just an after thought......

When's the last time you set the valves....??
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