Rotax 4-Tec Supercharger removal for rebuild

[danny4255]

Scarab 255 ID. Twin Rotax 4-Tec 250's supercharged. Has anyone removed the supercharger(s) for rebuilding? I can barely see them under the catalytic convertors, intake tubing, and plumbing. It looks like it's not too much fun laying over the engines and the external Torx bolt removal. I'm pretty mechanically inclined, just getting a bit old and sore for some of it anymore lol. Just looking for cautions, tips, and tricks. I can only find wave runer videos of course.

 

[Liberty195]

Is your boat 2017 or newer? If so it may not need rebuilt just inspected. Search the forum there is a post on when they stopped needing rebuilt and just need inspected.

 

[danny4255]

It's 2018, but to inspect/test, they need to be removed and Everyone I've asked said they are the same. Rotax only changed the recommendation for marketing purposes; pull and rebuild at 200 hours seems to be the prevailing advice.

 

[Liberty195]

To remove, inspect, and put back in is an Hour job or less for any mechanic that knows a rotax engine. My dealer said I can just pull up and wait while they inspect. Of course to rebuild or replace, which is the same cost, takes the job from a $150 inspection to. $1000 rebuild or replace. The difference between old and new is very obvious when you look inside.

When inspecting the mechanic looks at the tolerances and if it’s tight, all good, if it’s loose then time to replace or rebuild.

now that mine has 0 hours on it I intend to do an inspection after 1 summer, then again at 200 hours. If tolerances are good at 200 hours I would not rebuild or replace. Would just do annual inspection.

 

[danny4255]

Thanks, I appreciate the reply. Just so you know though, I spoke with several different rebuilders of these and they All said Rotax didn't change anything in the bearing design since they stopped using ceramic washers around 2008. They all strongly recommended complete rebuilds at 200 hours. I understand they may be biased due to older issues, but they insisted engine damage could occur if the SC bearings fail. I always over-maintain everything I own, so I'm just going to pull and send to the rebuilder for my confidence.

 

[Neutron]

It is not hard to do for the most part, one torx bolt is in a tight spot and needs a box end torx wrench to remove.