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[Highwaystar]

I am curious if anyone else has noticed piston rattle when the motor is cold. 1800 to 3500 RPM. I don't think it is not normal for an air cooled bike to have all sorts of noises and I am not that concerned. I have been told that the 110 pistons are very short skirted and the pistons are going to rattle a bit when cold. I take it easy when warming it up and it will go away. We are all aware of the normal excesive valve clatter and this is not that. I did not hear this with my last 103 se motor or.  loose toleances? any thoughts from any motor builders. Dan

[Guilty]

Last Saturday I noticed some piston noise betweek 2500 to 3500 rpm's and I thought at first that I must have got some bad gas. It seemed that after 10-15 minutes of riding it went away and I forgot about it. Maybe your theory regarding the cold engine is accurate.

[Gecko]

I have that on my SERK and it doesn't go away with heat.  Some people have reported that their dealer said the same thing about short pistons.  It may be "normal" for the 110, but it's not normal for something to be banging the cylinder wall forty or fifty time a second in an engine regardless of whether it is air cooled or not.

[SPIDERMAN]

FYI
      H-D builds their motors with cast pistons. Cast pistons are fit very loose meaning there's quite a bit of tolerence between the side of the piston and the cylinder wall. The idea behind this is that if you are one of the many out there who on occasion start your motor and twist the thottle to the max 30 seconds later your engine won't seize up. While it makes for a more idiot proof motor, it also causes some of the strange noises you hear when you start a stock H-D and until it warms up a bit. Especially if as you say the 110's have short skirts. Forged pistons are much stronger but are fit tighter so you could grenade a motor by the start and go scenario with forged pistons. They also cost more which is a big factor in the equation for H-D Inc I'm sure. Since my motors rarely make it more than 5,000 miles in stock condition, all of my rides have forged pistons. As such, I don't put up with this clatter but I also have to warm em up a bit before I take off. Can't have it both ways.

B B

[mad brad]

i was told the same thing my tc-88 is loud, has been 11k loud new never came apart hotter the louder it got,so bore it out too? 95 change too good piston and tighten up the ring gap . i would give up not warming it up to kick the clatter MAD BRAD

[grc]

Piston slap, as BB pointed out, is a function of piston to cylinder fit.  Considering how many folks have posted about the lousy dimensional quality of the 110 cylinders as received from H-D, I think that would be my first "suspect" when looking for a real cause for this problem.  Short skirts is just another of those BS answers we all get when talking to H-D and their uninformed dealers.  All TC pistons have relatively short skirts, but not all TC's have piston slap.

Jerry

[sadunbar]

Piston slap, as BB pointed out, is a function of piston to cylinder fit.  Considering how many folks have posted about the lousy dimensional quality of the 110 cylinders as received from H-D, I think that would be my first "suspect" when looking for a real cause for this problem.  Short skirts is just another of those BS answers we all get when talking to H-D and their uninformed dealers.  All TC pistons have relatively short skirts, but not all TC's have piston slap.

Jerry

Absolutely right, Jerry...

Axtell cylinders and CP forged pistons and rings significantly quieted my motor...   

http://www.axtellsales.com/

http://www.cppistons.com/