06 vmax 150, well maintained, lightly used.

I have had consistent problems getting the engine to start. Starts slow, have to crank for quite a while usually but will start sometimes. If cold (less than 60) and / or don't start for several days, it won't fire, just cranks. Eventually it might turn once, but doesn't really fire or try to start. If leave alone after first attempts for a couple hours will usually start.

Have had back to shop multiple times, on dry land in heat of day, it will fire for them. They did fix a choke problem (wasn't opening up all the way) which helped some but still slow to start (have to crank several seconds- often 2 or 3 times to get to fire at all) and today wouldn't start at all. Drive it to dealer and it fires up pretty quick.

So i have a boat that sometimes starts, often not, may start a few hours later, and almost always fires at dealers on dry land.

Hard for dealer to fix what won't happen there, but this is getting ridiculous. Any ideas for what might be wrong?

Any dealers here- have I got an option to get Yamaha to replace this lemon? Boats been in shop more than on water.