Rotax 503 stripdown???

[nickjaxe]

Hi guys in the next few weeks I am going to take my 503 its the electronic ingintion version to bits to give it a good check over, I have the service tools ie flywheel puller gearbox drive gear puller fan locking tool, but I have been told that some of the bolt may need a gas torch on them if they have had locktight on them in the past or I may end up stripping threads or rounding off bolt heads, any of you guys tell me what I need to look for in this department as the tghought of putting a gas torch on an ali block scares me its knowing how much heat to give it.

Nick.

[Miskiet]

If the guy that assembled it prior to you knew his stuff he will have used blue loctite (and sparingly) and torqued the bolts to the correct setting. Bolts should loosen easily by hand with a "pop". I disassembled my 503 without any need for a gas torch - I wouldn't use one either. Stripping the allen key bolthead is more likely to happen (drill head off & use vicegrip to loosen bolt) than stripping the thread.

Speak to someone at your airfield that has done it previously - offer to buy him a beer if he lends a hand. Check somewhere on this forum Rudi posted the 503 stripdown manual.

[Morph]

Here is Rudi's post on the subject

http://microlighters.co.za/viewtopic.php?t=2057

[nickjaxe]

Hi guys I have read rudis post in the past and very good it is to, I have the DVD from CPS in the usa ie re-building the 503 very useful, I was just looking for any snags peculiar to the 503, I have re-built many engines over the years but forearmed is forewarned as they say, I have also got the service tools that I think I may need.

Nick in the UK.

[Duck Rogers]

Nick, if you have a gearbox on the 503, then the only thing that's gonna need heat to come off is the reduction gear or doughnut thingie at the front of the crankshaft. (depends what box you have)
No need to apply huge fire to it either. If you have the right puller (or a homemade one) then you only need to apply reasonable pulling force to it and a paintstripper heatgun aimed at the reduction gear will do the rest. Should pop right off after a few minutes. No need for fire on the crankcase. :D

[nickjaxe]

Dont know what I was worrying about all came apart no probs even the drive gear came off easy just hope the rest goes as easy.

Nick.