Yamaha RD500 RZ500 2-Stroke Engine - Yamaha Power Valve System (YPVS) explained!!

[@leslieaustin151]

VERY interesting, but I’m glad I’m not working on it! Thanks. Your workshop combines the very old with the very fast. That is impressive. Les

[@thebracketfactory]

Thanks for watching Les. Weather getting better so hoping to get out in the Austin soon!

[@daviddjerassi]

EXCELLENT video step by step you show both power valves nothing to chance thank you i loved the video and learnt a lot keep safe.

[@thebracketfactory]

Cheers David 👍

[@shauntaylor9251]

Had a RD125LC when i was young and mad , it kicked at 3000rpm and again at 8000rpm Always wanted a 500

[@keithgarland3404]

Never seen a power valve system, like this, on two stroke engines. So interesting, and well presented.

[@thebracketfactory]

Thanks for watching Keith 👍

[@craigwatt7695]

Simply fantastic. Thanks Bracket Factory

[@thebracketfactory]

Cheers Craig!

[@nazdagg1945]

2 strokes were banned in the US before this era of technology, what a shame. good explanation.

[@homeblt]

Thank you so much for this. I’m a first timer…rebuilding the top end to get the old girl running again!😅

[@thebracketfactory]

glad you found it helpful - good luck with the re-build!

[@1xARM]

I had two 500's... and a 350 when I was young. Loved it. Kinda slow standard really, here in Australia, but I just tidied up the ports. I guess you'd call it a shade above blue printing. That and a few other things. After that it was pretty quick, SUPER fun to ride.

[@thebracketfactory]

They were (and still are!) a lot of fun .. 🙂

[@RachaelSA]

I want that motor! My first 3MA used to wear down that flat on the power valve, and my dad, a precision toolmaker, welded it the first time, the second time it happened, he made new ones with a different aluminium alloy and coated them with the same stuff he would vapour coat onto cutting tools and been over 20 years, and it never happened again.

[@thebracketfactory]

You were lucky to have a dad like that!! Actually the 3MA parts are almost identical to the RD500 lowers Its effectively half an RD500..

[@paulspringthorpe332]

Thanks for an excellent video - it’s a good idea to Loctite the power valve cap screws - they have a tendency to work loose over time - the temptation is then to over tighten the screw which can crack the tab off - don’t ask how I know 🙈

[@thebracketfactory]

That's a good tip Paul 👍

[@RussellBaker]

A 350YPVS and a couple of TZR's owner, I think it was the most elegant system, all the other's copied it to lesser degrees trying to avoid the patent, and yes those valves got gummed up with all sorts of gunk. Really noticable when a seal would start going on that outer cover.

[@thebracketfactory]

The TZR (1KT) his pretty much identical to the RD500 - the barrels and heads are pretty much the same - so it was effectively half of an RD500 (but with a better frame!)

[@kiztime1234]

9:55 for me it was some shim steel, was a real prick of a thing to do insitu.

[@thebracketfactory]

I bet that was a right pain!!

[@kiztime1234]

@@thebracketfactoryYeah I was still a kid, didn't really know any better! Made a big difference to the running of the bike though.

[@brandonotte3359]

Very well done! I have the 90 Fzr400 with EXUP valve. Does that rd500 have 2 crank shafts?

[@thebracketfactory]

Hi Brandon, yes it does have two shafts - I have done another video which gives a full overview of the engine which you might find interesting. A also have an FZR1000 Exup but the exup valve has seized solid - a very common problem! They need to be used!!!

[@shabbos-goy9407]

My pal bought an RD500 new. He told me these motors would nip up. One pot gets too hot. Old wives tale I cannot be sure...

[@kiztime1234]

I did nearly 50,000km on mine when I was 18, never blew up 😂

[@thebracketfactory]

wow - wonder what the power valve mech looked like after 50k!! @@kiztime1234

[@ChrisBirt]

Hi do you know if tzr250 powervalves fit the rd500 Cheers

[@thebracketfactory]

I think that they are very slightly different.. I have both so I'll check.

[@lahoz84]

Is there any modification to do on those valves to get more power?

[@thebracketfactory]

the only real mod is to just make the exhaust ports bigger, but that can't really be done in isolation - all the ports would need to be worked on together.

[@lahoz84]

@@thebracketfactory thank you!

[@Sunday_Builds]

Is that the same toothbrush as you use for your teeth?

[@thebracketfactory]

Congratulations Sunday Builds - you are the first viewer to spot the toothbrush! Your prize (the toothbrush) will be in the post to you... 👍