Hey fellas, I have a question about my boat's ability to get up on plane.  I have an 88 merc 135 mounted on an ebbtide 180 dynatrak and recently I have had problems getting the boat on plane as quick as it should.  I have a 14x21 alum prop and have tried several different pitches.  Found that this suits best, but when I bury the throttle the engine bogs down and sometimes never raps up to get on plane unless I stop it and use the high idle to rev it up a bit.  The weather here has been very hot and humid and I didn't notice any problems early in the season.  I don't know if the secondary throttle? isn't working properly because it idles, starts and runs at wot like a champ.  Installed ngk plugs and that was a major improvement at crusing speed, just can't get the thing out of the water.  Thanks for your time.

Tony

It's likely carb jetting that is too rich.  I have dealt with this in the past myself.  If you have no experience with jetting carbs ask your local dealer for advice.  Most any manufacturer will sell their engine with richer than needed jetting to maintain a safety factor as a safeguard against warranty claims.  My guess is you could probably go a little bit leaner on jetting and still be safe year around if you don't over do it.  If you jet on the edge, then be prepared to jet it back when it is cooler out again.  

I went through this a lot with my 1990 Johnson GT 150.  It was a total pig in the heat and sucked a LOT more gas then it needed to.

Well I slapped the factory prop back on, tightened up the throttle friction a little, cleaned out the carb cover area and it ran like an animal.  I had found that my fuel line had become slightly pinched due to a zip tie back towards the transom.  Now, I need to figure out which fix helped remedy the hesitation.  I have a 15x17 stock prop and WAS running a 14x21 solas alcup.  Having a hard time accepting the fact that the solas was too much prop.  It was turning 5300 at WOT with solas and the stock is screaming at 62-6300.  I was right to scale that rpm back a little right?  Maybe a 19.  I just don't see giving up the acceleration and performance for 3-4 mph top end gain.  Sure seems like it is turning too much to be good, even at a decent cruising speed.  I thought that the 21 would be a perfect fit, you know, hitting the WOT range in the middle.  You guys weren't lying about propping a boat.  It's a certain trial and error ba$i$!!!