2000 90HP stalls under load

Bought a Carolina Skiff with a Honda BF90AY all 2000.Dumped the old fuel and cleaned tank and put new fuel in.Replaced the entire Racor filter and it ran great in the driveway.Put the boat in the water and it would stall under a load at about 1200 rpm's.So replaced the fuel line and internal filter,same thing.Gauged the fuel pumps both at 7psi did a compression check,all cylinders at 125psi,then sent the carbs out to be cleaned and rebuilt.Carbs were cleaned in an ultrasonic tank.Reinstalled carbs and synced them to 30.Now it stalls at 1500 rpm's.Im at a loss,any ideas out there.

Also this motor had only 477 hours on it when I bought it.

Thanks for the tip Capt. Ill try anything,been in the slip since May and haven't been out once.

Well...you got 300 more rpm...

Compression should be more like 212 psi plus/minus 14 psi at 300 rpm. At least a lot closer to 200. Be sure to check with the throttle wide open. That, hopefully, is the reason for the low compression.

Does the fuel pressure stay at 7 when when you try to accelerate above 1500 rpms?

I do not understand how you sync'd the carbs to 30. They should all be sync'd to #4 carburetor. That is the reference. It does not matter what the vacuum reads on it.

It sounds like the carbs may not be completely cleaned. If they did not clean out the intermediate passages...there are two besides the idle passage....then they are not going to accelerate properly. In spite of what many seem to say, the 90's carbs can be difficult to clean properly, unless you know what is going on in the passages and actually can spray fluid through them and watch how the spray goes through.

Make sure that the dashpot valve #18 http://www.boats.net/parts/search/Honda/Outboard%20Engine/2000/BF90AY%20LRTA%20/THROTTLE%20CAM/parts.html is pointing towards the carbs.

As always, I highly recommend the Honda Carburator Manual sold by helminc.com http://www.helminc.com/helm/product...=&from=result&Style=helm&Sku=TM044&itemtype=N

It has excellent instructions and colored pictures....especially for the 90.

Mike

Thanks for the info Mike,will recheck compression,it was actually 175 psi.My brother-in-law has a auto shop and is helping,checked with him,I had it wrong.Will recheck the fuel pumps,good advice.#4 carb was at a vacuum of 30 so all were adjusted to 30.I sent the carbs out to a place in York Town VA and I hope they throughly cleaned everything in the carbs for what I paid them.Shot them an e-mail asking about it.Once again thank you for all the good advice.Ready to use this thing for an anchor.

Also Mike intermediate jets are all new.

Found the problem,bypassed the new Racor unit I installed and the motor runs great.All I can figure is the Racor is defective because its the same unit I removed from the boat when I bought it.

Glad you found the problem.

Mike

It's a good practice to replace the Racor filter every season or every 200 hours, whichever comes first. They do clog up in some circumstances. Also, not unusual for the seal or the connections to draw in air under load if they are not installed properly. Don't make your bypass permanent.