Rotax rebuild

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Postby detroit » Fri Aug 06, 2004 12:45 pm

I've recently purchased a Lazair S III that came with 3 rotax 185 engines. They were not in running condition when I purchased. Am looking for information and tips on what to look out for when rebuilding these engines. Specifically any differences in these from say air cooled 2-stroke motorcycle engines.
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Joined: Fri Aug 06, 2004 12:33 pm

Postby Guest » Fri Aug 06, 2004 12:59 pm


Call Wildfire and purchase the flywheel puller and the condensor removal/install tool. Then purchase new points and condensors from them as well. Remember to tell them it's for the Mark-3 fire pump, don't mention airplane anything.

You will need to check compression, leaks around the seals and a few other things before calling just in case you need rings or seals etc.

If these engines have sat for any length of time they will need to be looked at carefully. They are a wonderful and durable engine that can be brought back to life and serve you well.

Look them over and report back.

Postby Guest » Mon Aug 09, 2004 6:43 pm

Thx. Does Wildfire have a website or a telephone number..? I can't find them anywhere.

Postby Guest » Mon Aug 09, 2004 9:43 pm

Guest @ Aug 9 2004, 06:43 PM wrote: Thx. Does Wildfire have a website or a telephone number..? I can't find them anywhere.

Multiple dealers.

Get specialized tools and right ignition parts from Wildfire
Time to approx .15-.17" BTDC with TDC guage (w/18mm adapter) and meter
Rebuild or replace the carbs (kits available other than from Wildfire)
Change out the original sparkplug cap
Safety Wire Carb nuts (drill nuts not studs, cross-wire)
Safety Wire Sparkplug cap
Check Head Torque (210 in/lbs)
Check compression release aluminum heads (tac weld end of stem)
30-34:1 ratio Pennzoil air-cooled, 89 or better octane

Tune carbs, run engines, and check RPM's with Tach. Idle 1900, full revs 5,800+ with dual props. Report problems.

Postby Guest » Wed Oct 06, 2004 2:12 pm

Does anyone know the optimal compression a 185 should have..? A free flowing piston without the head, has turned into a bear to pull with head screwed on.

Postby Guest » Wed Oct 06, 2004 8:04 pm

No idea what max compression is ? Sounds normal though. With new rings the engines are extremely hard to turn over by hand. Real B$%@# !

Postby Guest » Wed Oct 20, 2004 7:22 am

Anyone know where to purchase a 'buzz box' relatively cheaply? LEAF has them but go for 50 bucks.

Postby JPXman » Wed Oct 20, 2004 12:44 pm

what is a buzz box? if its what i think it is, it'd be pretty cheap and cheerful to make yourself.
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Postby lazairiii » Wed Oct 20, 2004 9:25 pm

I picked up a multimeter (digital) at Harbor Freight for under $10, and it works exceptionally well for timing my 185's.
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Postby Guest » Thu Oct 21, 2004 7:15 pm

Here's a link to Harbor Freight On-line. You can view the whole selection. No need to spend $50. Type in "multimeter" in the keyword search box.


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