Malossi 172 running in period - conflicting info!!

[Keeko]

As I eagerly await my 172 kit arriving via the postman, I've been reading some info on the running in period. The instructions that come with the kit suggest not exceeding 45mph for the first 300 miles but wasp performance have a document that states you should only maintain half throttle for the first 50 miles, then ease towards full throttle for the next 50 before considering the kit run in. Can anyone with experience of these kits advise any further?

[Adam_Winstone]

Running in... as with a brand new T5, back in the day, you probably only needed to do 50 miles of bedding in rings and bearings, then you could absolutely cane it at WOT without issue... HOWEVER, that was on a factory configured motor that had thousands of development hours put into ensuring that all aspects of the motor were perfectly balanced for production reliability, which an aftermarket kitted engine without this developent does not have!

IMO you need to spend the first thousand miles monitoring and testing your set up to ensure that ignition timing, compression, jetting, fuel flow, etc. are all correct before you even worry about whether the rings and bearings are run in. Regardless of what it takes to bed in rings and bearings, you'll have bigger issues to worry about for 1000 miles, in which time you need to do some work to ensure that all else is well.

All the best with this and I hope that you get it set up and sorted so that it gives you the fun factor and performance that this kit does deliver, if set up correctly.

Adam

[Keeko]

Cheers Adam, sounds ominous!

[gaz_powell]

Not ominous just sound advise, jetting I touched on I th kit instructions but will depend on pipe.
I built a very reliable 172 with no issues.
Jetted large (128) to start to work with a JL RH and came down to get it right, timing left standard, do forget you need to modify the head.
Run in as per the malossi instructions.
Gaz

[gaz_powell]

Typing while walking...... don't forget you need to modify the head....

[drunkmunkey6969]

Setup and running in are not the same thing, in my opinion. As pointed out, you can spend hundreds of miles 'setting up' an engine, as you tweak jetting, timing and other bits n bobs. Getting those bits right or wrong will be of most importance.

But in terms of actually 'running in' the piston, rings and bore....on a Malossi 172 ...personally I'd just thrash it from the word go.




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[Chris in Margate]

I have always felt that the advice to run at 1/2 throttle and full throttle to be way off what should really happen.
I always treat an engine similar to a geared push bike in so much as I don't want "my legs to start aching". In other words you should avoid labouring the engine under load. 45mph uphill is obviously more stressful than 45mph downhill. It's about keeping the engine spinning freely without any excessive load. This means changing down when you feel the engine start to work hard; even at 35-40mph it can be under extreme load especially if on any sort of incline and a slight headwind.
Up and down through the gears is the way.

Conversely as others say: I had a brand new factory fresh PX200 and treated that with total disdain and ruthlessness ftom the off and it never let me down !

[ducksta]

Setup and running in are not the same thing, in my opinion. As pointed out, you can spend hundreds of miles 'setting up' an engine, as you tweak jetting, timing and other bits n bobs. Getting those bits right or wrong will be of most importance.

But in terms of actually 'running in' the piston, rings and bore....on a Malossi 172 ...personally I'd just thrash it from the word go.




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To be honest I had mine built by chiselspeed 8 years ago + dynoed then picked it up then went easy for about 5 miles then give it some never run it in and it has never missed a beat.

[Keeko]

Thanks guys, I'll let you know how my experience goes (if the kit ever arrives!! - beedspeed are awfully slow). Chiselspeed had the head modified and posted back within 48 hours- well impressed.

[ducksta]

How did the running in go