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View Full Version : Help me with Hirth


MrGrey
05-24-2005, 04:15 PM
OK, I have purchased a 2703 Hirth 55hp Dual Carb, Dual Ignition, Rebuilt with 0 hrs. Can anyone help me find more information (manuals, literature, etc.) Also any comments on the engine that might be noteworthy would be appreciated.

scottessex
05-24-2005, 04:49 PM
Call RPE and get some manuals, http://www.recpower.com/
Just for the sake of it, run thier Blue Max oil like they recomend, at the correct ratio. (100to1)
Get a good small torque wrench and make sure that you torque the spark plus correctly. (108 lbin) also put a drop of red loctite on the threads of the spark plug tops, the little nub on top. then screw them back on.
DO NOT overheat the engine! make sure that you use CHT as well as EGT check your belt tension on the fan as per the manual.
I like the way my Hirth 2706 (65hp) runs, it has plenty of power and it has been running very well.
Let me know if you have any other questions.

I know alot of people here don't like hirth, but they are different than Rotax, They use a hyperutectic pistons and nikasil plated cylinder, also the heads have no gasket, they use a chamfer ground seal that is part of the head, the head cannot be resurfaced. The cylinders cannot be bored.
Rotax uses cast alum pistons and cast iron cylinder liners.
Hirth does not have the dealer network, That rotax enjoys, the old north American supplier was out of Canada and was not very easy to deal with. RPE has been very good, and I have even been able to E-mail and speak to thier technician on the phone.

Hirth did have some problems with the crankshafts being out of true in some of the earlier engines.