Well my new motor has a little over 10 hours on it and it's only turning 3400-3460 RPMs @ 18mph. Im running a brand new Hopkins 8.75x6 prop. I can put two people in the boat and a few extras things for fishing and still turn the same RPMs. Out of the water I can turn over a hair over 4000.

Is my prop too big? I've check the butterfly on the carb and its opening fully.

The motor is a 23hp Vanguard mounted to a longtail frame and the boat is a 15' RiverHawk.

Also I have terrible stumble when you gas the throttle from idle. So bad the engine shuts off. Im idling aroud 1400rpms out of the water if I recall correctly.

Any ideas or concerns?

Im not sure if a carb kit is really worth the $700.

No motor Guru's want to share any knowledge?

Try different fuel as a start, My motor ,Altough modified, has a 300-400 rpm difference between fuels. Also look for mud buddys governor modification/adjustment. That combination sounds like your problem.



P.S. the carb and exaust mods are worth it

As far as the stumble goes, that is more than likely a carb problem (needs cleaning). But 18 mph with a 23 hp longtail with 2 people and gear is normal to a little above average. I wouldnt let the rpms bother you, cause as you start to wear the prop it will pick up some rpms.

Since my engine is so new, will I need a gasket set for my carb or will the old ones be ok? I'd hate to pull it apart and not have the gaskets to put it back together.

110 views..wow....

Does anyone on here know what my OOW idle should be?

I still have the bog.

Im not a motor guy but i know that 4000 rpms is the max on manufacters warranty.If you go over that voids the warranty.If you care hope it helps

since you have your ten break in hours... have you checked your valve lash yet...?

[quote="SuperDave4x4"I have not checked my valve lash. The motor has been bogging long before I hit 10 hours. I can check it though.[/quote]

wouldn't hurt to check just for piece of mind... needs to be done anyways

Is there a write up on here for clearences and if it needs to be in TDC?

.004-.006 1/4 past tdc on the compression stroke. I would set the idle as low as you can without making it stall when you drop the prop in the water.

Well it is just about as low as I can get it then. 1200ish RPM @ Idle.

Ill check the valves tomorrow..

Here is alittle video I found. Just another way to set the clearances.

http://www.youtube.com/watch?v=hGkn0jR9RJM