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Guest joe

Rotax 618

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Guest joe

Has anyone had experience with or currently running a 618? I understand

that Rotax do not manufacture any more as they were marginally less HP

then the 912 & 1/2 the price, thus too much competition for 912

sales. Is this correct??

 

 

 

any insigst experence with the 618 would be greatly appreciated. cheers, Joe

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Guest micgrace

Hi,

 

I went for a flight in a lightwing quite a while ago where

the owner had changed from a 582 to a 618. According to the owner and

my own own observations, didn't seem to make much difference to

performance, and the 618 seemed to suffer from a lot of problems that

didn't seem to afflict the 582. MaybeRotax decided to rationliseand

just stay with the 582. From memory there was only 5 hp in it

 

Actually the single cylinder engines are dropped as well.

 

Micgracesmiley1.gif

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HI all, since this thread is 4 years old, i was wondering how this engine 618 has performed.Also i have read it has a power valve (RAVE), similar i guess to 2 stroke motorcross bikes.

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Hi,

I have 290 hrs on the 618 in my gyro and no problems. It gets worked pretty hard too, cruise at between 5800 & 6000 rpm.

 

Rob

  • Caution 1

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HI Guys, is there a specific reason why Rotax stopped making them.I read on the net, it may have been because it was only 5 HP, less than the 80 HP Rotax 4 stroke and alot cheaper.Have you guys heard anything.Also are parts easily attained.Thankyou in Advance

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The 618 is a powerfull engine when running fine, it had an adjustable RAVE (Rotax Adjustable variable exhaust ?) set up on the exhaust outlet, that adjusted the exhaust backpressure via a slide reed valve set-up. There is one instance of a failure up here in the North where the movable slide let go, and contacted the piston, stopping the engine of course.

The 582 on the other hand has become a reliable classic delivering a reliable 65 HP.

Not sure why Rotax discontinued the 618 engine...................................Maj...:cool:

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Hi,

I have 290 hrs on the 618 in my gyro and no problems. It gets worked pretty hard too, cruise at between 5800 & 6000 rpm.

 

Rob

Hi Rob, would you tell me what size main jet I should have in my 618 carbs. I get it with .135, and started to stepping up as the engine was doing better and better. At this point the engine running fine with "drilled up" size ( I lost my temper once , ) The plugs and the exhaust color good as can be, running reliably ( like this engine, is so simple and light)

My exhaust temperature is what is not where is should be ( as I know!) 725 F, when I throttle back goes up to 830.?? I would appreciate any education on this.

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My exhaust temperature is what is not where is should be ( as I know!) 725 F, when I throttle back goes up to 830.?? I would appreciate any education on this.

 

Is it just me,Or can everyone hear that ticking noise?

  • Agree 2

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The 618 engine requires two jet sizes -# 135 for PTO carb, #145 for the MAG carb. It is the only Rotax 2 stroke with this requirement. The 618 is a very reliable engine, it weighs considerably more than the 582 even though they share the same pistons, the weight is in the very strong crankshaft. The performance difference between the 582 and 618 is chalk and cheese.

The 618 is a detuned 670 snow mobile engine, the 670 is single ignition and is rated at 135HP.

Unfortunately the 618 requires a very large and heavy oval muffler. Although the RAVE valves automatically open by air pressure at altitudes less than 5000 ft they should be connected to a cable so that they can be cleared and exercised prior to and after every flight.

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Also pays to remove the rave valves and clean the carbon off or they may stick .you will know when they stick, 628 will run rough when power setting is changed as one will stick open and when power is reduced only one will close

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Also pays to remove the rave valves and clean the carbon off or they may stick .you will know when they stick, 628 will run rough when power setting is changed as one will stick open and when power is reduced only one will close

Thank you spyfly, so far I had no rough running problem, starts good, runs good . I am just not sure I get all the power out of it. My exhaust temp is 730, and goes up on the reduced power to 840.(I do not know my MGL how accurate is?) As I know it should be higher when the engine giving out all its power. My exhaust color is just as good as can be, and interestingly at the first take off ( when is not completely warm) I get 7k rpm, at the next take off 6400,??

Thanks

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