Pro-X Piston Clearance

[Economy Cycle John]

Thanks for all the comments.

This guy doesn't care how good it runs, he just cares how it sounds at idle. This all started with a rebore because he ran it out of oil. He installed the top end himself, we just bored and supplied pistons. He says we (Scott C)/EC) bored his cylinders incorrectly and supplied the wrong pistons, TKJR LC pistons. 

And the bike came in with low top carb bodies with high top caps and slides. I put up a post about them a while back. So I swapped out the caps/slides for low top ones and now he says I stole his original high top carbs, never mind that the black paint on the caps was flaking but the carb bodies were obviously never painted.

The sad thing is his rd runs great now from idle to redline and is a nice original 75 other than low top carbs.

[m in sc]

maybe send him a set of fin isolators and a cry towel.

[Economy Cycle John]

Yup we installed the dampers. After we did the work he proceeded to send this video to "shops" in India for video diagnosis, and they all agreed with him its FUBAR. Here's his comment, the first paragraph of a 10 paragraph list of complaints accusing me of incompetence, theft, and a littany of other complaints. Maybe I'm old an my hearing ain't so good but it sounds like every other stock RD to me and it runs great, doesn't miss a beat to redline.

"1) When i got the cylinders back after a month+ long wait, I was shocked to see that i got the piston boxes with 350LC written on it and one piston feels looser than other when moved by hand when they are inside the cylinders. I was expecting that you would check with me before making a decision to install a Liquid Cooled pistons into an Air cooled engine. It is a well known fact that these pistons have different characteristics and it's not a best practice to install them in an aircooled engine and will cause issues. (Confirmed by repair shops in the RD business in India )"

wonder what he'd say about forged pistons with .003

And mind you he approved an estimate with TKJR pistons bored at .002, but appearantly didn't read it.

https://www.dotheton.com/data/video/112/112736-ac6a610c3e0a501bf18d1709277d5f25.mp4

[m in sc]

I've said this before. Not often, but have said it in person in a business situation:

"some customers aren't worth having"

don't let this fool sweat you, and if he ever comes back, just tell him to take his business elsewhere. 

fuck that guy.

[teazer]

Mark pointed out that LA Sleeve recommends 2.5 thou or thereabouts for those pistons, so if the owner wants specific pistons and specific clearances it is his responsibility to clearly ask for that.  If not he gets what the professional (you) recommends.  That's why we use professionals.

If I want something machined a certain way it is my responsibility to communicate that clearly to the machinist and 100% my responsibility if they do what I ask them to do and it doesn't work. The OP doesn't actually know enough to know what he wants, but thinks he knows enough to be a critic.  Touch of the old Dunning-Kruger effect there methinks.

Just to throw a money wrench into the mix, that RD does sound loud to me with my acoustically perfect (cheap) computer speakers and calibrated (not) ears. Is it possible that his big ends are a touch loose? Or is that just the effect of a cheap phone microphone?  If he seized it when it ran out of oil, the big ends may be damaged. Just a thought. I expect to hear a higher pitched tapping/ringing sound with piston slap (clearance).  On my PC that sounds deeper than I expected.

Either way, the OP is acting like a dick.

[m in sc]

some digital cameras enhance those noises or what sounds like piston slap to a strange level. My fresh LC top-end on cell-ph camera sounds unbelievably awful. but.. its not.

[SoCal250]

I've said this before. Not often, but have said it in person in a business situation:

"some customers aren't worth having"

don't let this fool sweat you, and if he ever comes back, just tell him to take his business elsewhere. 

fuck that guy.

+1
IMHO if he ever comes back just tell him to get his rebuild done in India!  What a tool!

[Economy Cycle John]

yeah and that's just it, I've explained to him that "piston rattle, piston slap and I think it sounds loud" are laymen's terms and aren't specifications especially from a video. I've owned a lot of RD's from brand new 1978 to every other incarnation stock and otherwise pretty sure I know how they should sound. The UK aircooled guys told him .002 is worn out. He didn't ask me to rebuild his engine, initially he just brought me the cyl's for boring/pistons. He then put it together himself and ran it then asked me to check it out because he thinks it doesn't sound right and something is terribly wrong. He then brought me the bike, fixed his Frankencarbs (low tops with high top slides/caps) ultrasonicaly cleaned his carbs, timed it and some other small stuff and install the dampers. I test rode it a lot, rode it home a couple times which I always do, then let it sit for couple days to make sure no leaks, then rode it again. It makes great compression and runs fine, really strong. He also listened to and rode my stock 400 which sounds the same.

There is no remedy for his problem anyway becuase you can't get Yamaha OEM RD pistons commercially anymore and bore the jugs to original Yam spec of .0015, so we're not going to rebore it and provide new pistons to be part of his "piston rattle" and "moved it with my fingers" and video diagnosis experiment.

You don't see customer complaints about EC becuase I just eat it if it's even questionable. I could and maybe should tell him what every other shop would, you put it together and ran it so don't blame us.

[m in sc]

ID TELL HIM IF HE SUPPLIED OEM PISTONS YOU WOULD HAVE BORED IT TO THAT SPEC. BUT, ALAS.

[85RZwade]

John, it sounds to me like you've done absolutely everything you can and should for this fella. Letting him ride your personal bike is, in my opinion, going way above and beyond. Kudos to you, sir.

[1976RD400C]

Here's one with oem pistons and the measurements were made with a bore gauge and a good quality micrometer.  .0018 clearance on one  piston and about .002 on the other. I used a Go Pro that was not in a case.
https://www.youtube.com/watch?v=AY64Vk0xVBc

[Economy Cycle John]

Yup sounds like an RD. Sometimes I have to tell guys that just bought an RD that they are old unsophisticated motors with noisy clutches, points, vibrating fins, they smoke, are completely analog half century oid AC bikes, not new 2021 CB250's and the expectation can't be the same. It's easy to over think it if you're used to modern tech or your memory of them is decades old. If you "think" it sounds funny but it runs fine, then it's probably fine. And when there IS actually something wrong you'll definitely "know" becuase the noises will be awful, metal on metal, scraping, loss of power, soft seizing, failed bearings, rods, etc.

And when you blow by that new CB250 or throw a set of chambers on it and go KTM Duke 390 hunting (great bike no offense Mark think you have one), you'll love the way your RD sounds or won't care. They are easy to hot rod, easy to work on and you'll never get embarassed competing with modern bikes of similar displacement, and that's the reason we're all riding them, there's tons of parts, great forums etc, some half century after they were built.

And I tell them whatever you want to do to your RD has already been done, the body of knowledge is vast and it's one of the best vintage bike choices you could make!

[m in sc]

had one.got rid of it for the CB1100

who knows what this guys goals was. however, with the aging group now into these things, we are def getting into the heavier priced but more frequent uneducated douchebag 1st timers that will blow thru this phase in a few yrs.

[Striker1423]

had one.got rid of it for the CB1100

who knows what this guys goals was. however, with the aging group now into these things, we are def getting into the heavier priced but more frequent uneducated douchebag 1st timers that will blow thru this phase in a few yrs.

Me withstanding of course lol.

I'm too into it now to give up. 

[Striker1423]

had one.got rid of it for the CB1100

who knows what this guys goals was. however, with the aging group now into these things, we are def getting into the heavier priced but more frequent uneducated douchebag 1st timers that will blow thru this phase in a few yrs.

Me notwithstanding of course lol.

I'm too into it now to give up.