Proper LC engine break in 1st 500kms (300mi) counter view

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evan_calgary
Posts: 1368
Joined: Tue Nov 12, 2013 2:34 am

Re: Proper LC engine break in 1st 500kms (300mi) counter vie

#31 Post by evan_calgary » Fri Jul 28, 2017 8:33 pm

I must say Rory is the local expert when it comes to actual in the seat miles on these bikes having ridden and raced a pile of what Yamaha had to offer in the twin years. After having spent some time with the guy he doesn't seem like the type to even embellish when it comes to the mechanical stories.

I am tempted to get the TZR on the dyno with him as jetting coach based on what I have heard. I don't think it wise to call him out on his actual experience as, as far as I know, it is all legit. Quite possible this was due to your jetting Rory? By all regards it seems wildly lean but experience does show it works.

MOST of these motors do not get to the point of actual failure due to wear. Something happens...oil pump fails, jetting wrong, bottom end seal fails, bad rebuild or sit and rust. I can't recall (sure they are out there) a rebuild thread when the person who built the motor is rebuilding it due to actual need after use without failure of a component.

These were super durable and downright cheap bikes when released. They run well. They run long. The banshee side of things can attest to this as well.

Glad your break in went well. It is a topic brought up so often which I understand given the large investment of money and time to rebuild but I don't think the 100+ or even 50km+ time is really worth the amount of discussion it gets. Then again, maybe after I blow up a few motors I will have a different opinion. My TZR runs idle to redline duty the entire time it is ridden. That will be the first to blow if anything and it is basically ust a small, slightly updated RZ which in turn is an updated LC...

hondaror
Posts: 2828
Joined: Mon Mar 03, 2014 8:44 pm
Location: Alberta, Canada

Re: Proper LC engine break in 1st 500kms (300mi) counter vie

#32 Post by hondaror » Sat Jul 29, 2017 9:34 pm

The key to success is jetting and riding them hard.

Thanks Evan for the kind words.

Really glad Scott, that things are cooking on the island!!!
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

Bare
Posts: 1196
Joined: Sun Jan 29, 2006 2:18 am
Location: vancouver

Re: Proper LC engine break in 1st 500kms (300mi) counter vie

#33 Post by Bare » Mon Sep 25, 2017 9:11 pm

hondaror wrote: Sorry, my TZ250s used to get three weekends of riding, then the tear down, inspection and rebuild as necessary. My '81 LC, 106,000 kms on original crank, with a top end rebuild at 50,000kms because of piston slap.
An RZ350 at 50-60 claimed hp, does not compare to a TZ250's 79 claimed hp. No comparing the performance or reliability of the two. The full blown racer requires much more effort, $$$$. The street bike can and was flogged daily, raced, neglected, overevved, modified, wheelied, and it is exceptional with regards to reliability. I don't think you should pretend to know what I put my LC through in 9 years, and I don't appreciate being called incapable, or a liar.
3 Race outings ? Possibly not in Serious races then? That's typ privateer territory.
When Yama supplied the machines and paid the riders to run major race events towards titles.
The riders USED their bikes up at frightening rates.
Telltales on Tachs had heavy usage . Rebuilds were constant.
We had crates of parts and complete fresh engines on hand.. always.

100,000 kms onna lc crank ? that is Utterly Incredible durability :-)
You clearly have Magic Hands my friend.
LC crank assemblies weren't the most durable ever produced.. and rarely reach Half that mileage still healthy... Clearly a major accomplishment therein.
You could be the first owner ...ever.
Wonder if Yama hands out Lapel pins.. as VW did for extreme mileages.

I would love My pistons to hit 50k.....however 20 k remains as a goal.
Whatever.. it's your World. Be happy in it.

hondaror
Posts: 2828
Joined: Mon Mar 03, 2014 8:44 pm
Location: Alberta, Canada

Re: Proper LC engine break in 1st 500kms (300mi) counter vie

#34 Post by hondaror » Wed Sep 27, 2017 1:38 am

I have to laugh. Yes, I was an amateur, privateer rider. I call all races serious events. I also, have as much fun as possible.
I'll take the magic hands comment as a compliment, but frankly, proper and safe jetting (13.8:1 air fuel mixture), and riding the snot out of a 2 stroke, without over revving is key. Missed shifts? Yeah, happens to everyone.
As far as the motorcycling public goes, I'm above average as far as riding ability goes, but Factory rider? Not a chance, not even close. Factory backed? Could only dream about that. As a racer, most didn't give a shit about their bikes, they wanted to finish first at all costs. I was a poor kid, going out for fun. I tried to do my best and tried not to crash. Those things really mattered to me. I couldn't afford to repair a bike after every race, so, I cared about my bikes. I guess you were living the life of a Factory wrench/rider/whatever, no need to test reliability, and the riders just don't give a shit about the bike as long as it's fast and they can win.
Not sure if you know who Ricky Johnson was, but after one of his rookie wins they tore down his YZ250 to see if he was cheating, and they said the engine was so badly worn, it should not have been running.
I worked at a couple of large motorcycle dealerships in the service department in the 1980s. Most RZ500s that went out on the streets in Toronto seized the left rear cylinder. They came into the shops in droves. Jetting too rich, and the bikes not piloted hard enough. The RZ350 line up was pretty impressive too. Everything from empty injector tanks to engine failure from abuse/neglect. AND the crashes, so many down and rashed up.
My RZ500s ran great after rejetting. I also happen to ride the bikes hard. My 2 stroke training came from racing motocross off and on for 9 seasons. Then road racing the RD350, RZ500, and 3 TZ250s. A coworker, Glenn Condi and I finished 12th in a Pro-Am endurance race on my RZ500.
In all my years of riding/racing, I seized my JT60 when I was 14, due to water in my injector tank, and one of my TZ250s due to excessive top end wear, on the back straight at Mosport @ 140mph. Lesson learned. The TZs command attention with regards to hours run.
I currently have 11 RZ350s, most of which, are basket cases. Piles of RZ parts. In the parts are twisted up cranks, that I've never seen the likes of, and I've seen dozens of cooked RDs/RZs. I also have 3 LC engines, as I really like the punch they provide. So, if we both continue on our healthy lives, you'll read more about me, hopefully, about my build, and track adventures, as that's what I plan on doing, riding what I build and/or restore. As far as my world goes? I'm one of the happiest people I know. Many tell me, I'm the happiest person they know. I think that a happy attitude and the cost effective RZs are a great recipe for a fun life.

For the record, I don't recommend shooting for 50,000 kms on a set of RD pistons, but I'm happy to say, I've done that twice...so far.

Oh, with regards to the op, 1/2 a tank of gas is all you need for a good engine break in period. Done it so many times...but start with 3 warm-up cycles, and a head retorque.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

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