Maico 440 piston in RM 400

[rmbing68]

Hey guys, I'm installing a Maico 440 piston in my '79 RM 400. Ran into one problem, the side to side play on the piston end of the rod. I have .160" side to side play. My engine builder said we need shims/thrust washers here, to limit the side to side play. What did you guys do to eliminate this? Any help would be appreciated.

I'm looking at 18mm id x 28-30mm od x 1.5mm thick, thanks.

[Toolboy]

I fitted Wiseco 440 piston to my RM400 and did not have this issue.
I don't have the part No with me but can get in a few days

Tim

[rmbing68]

Tim, thanks for the info. I'm using a Wossner piston.

Ralph

[JohnnyO]

A little bit of side play doesn't matter the piston can't go anywhere, the tight clearance at the big end keeps everything in line

[DR500]

You have thrust washers on the big end , which stop side to side movement of rod.Piston small ends need the clearance

[firko]

I may be asking a dumb question but why use a Maico piston? Are Suzuki pistons unavailable or is it an oversize thing?.........Just curious as Maico Mahle forged pistons are heavy old buggers, I'd assume a fair bit heavier than the Suzuki item which would possibly throw the balance factor out a tad.

[Mutch]

Rick Horvat in the states does a 1mm os for the RM400
[email protected]

[bikebuzzard]

When installing the Maico pistons in the RM400 - be sure to use the MAICO wrist pin bearing....it is wider than the Suzuki bearing and that piston was made for the Maico bearing anyway!....( all the other measurements are the same as the Original Suzuki Bearing )