History of the Yamaha YZ80 1974-2001 + Tuning tips , Flaws&Fixes / DirtBikeDudeZ
Vložit
- čas přidán 6. 02. 2015
- The History of the Yamaha YZ80 from 1974 to 2001.
Leave a comment and SUBSCRIBE for more Yamaha YZ and dirt bike infos ;)
History:
The Yamaha YZ80 was a two-stroke motorcross dirtbike produced by Yamaha from
1974 to 2001.
Altough the YZ80 is a good bike for expert mini riders due to an abundance of high
rpm power and good suspension, it has too little low-end and midrange power for
most riders.
The problem is a combination of radical port timing and high gearing.
Like most of the minis, the YZ doesn´t have the quick response to keep up with the
RM´s out of turns.
1993-2001 Yamaha YZ80
Flaws: poor low-end power, non-adjustable forks
Fixes: cylinder and head mods, adjustable base valve
Cylinder mods:
Here is a way to get more midrange power from the YZ80. Turn down the base of the cylinder
.028 inch or 0,7mm and remove the same amount from the squish band of the cylinder head.
This retards the port timing and reduces the port duration, plus increases the compression ratio.
Intake:
Install a set of Boyesen dual-stage reeds for better throttle response.
Expert riders prefer changing to a larger carb (28mm flatslide Keihin) for more overrev.
Gearing:
The stock gearing is too high and should be changed to 12/52, for quicker acceleration.
Gearbox:
Earlier models had problems with the wear on the gear teeth of the second gear.
Yamaha has since improved the gear and pulled all the old parts from stock. If you ever have to
split the cases for engine rebuilding, check the gear teeth for wear. The wear pattern looks like
corrosion. Replace the worn gear and the corresponding gear.
Clutch:
Yamaha recommends switching to stiffer springs. The part No. is: 90501-216A6.
Forks:
The forks can be improved greatly by installing an adjustable base valve kit.
This makes the forks plusher. There are two options for base valves: 1992 YZ125 OEM base valve
or a tuned valve from Pro-Racing or Race Tech.
The stock fork and shock springs are too soft for most riders. The way to check the spring rate is
to set the race sag to 75mm in the rear and check the unladen sag (bike´s own weight without rider).
If the unladen sag is under 10mm, then you need to install a stiffer shock spring.
The front fork sag should be between 20 and 30mm. If the forks sag more than 30mm then you need
to install stiffer fork springs.
1993-2001 YZ100 Conversion:
If you want to convert a YZ80 into a big-wheel 100, it is possible with a combination of aftermarket
engine and OEM parts.
!!!KEEP ON BRAAAAPIN!!!
DirtBikeDudeZ - Auta a dopravní prostředky
Thanks for the showing all the YZs! Back in the 70's I owned and raced the YZ80A, B, C, E, F (all bought 2nd hand). I still have the YZ80G (bought brand new 1980). At the time I had someone give it a radical port job and special reeds, pretty powerful for a small motor. I won and placed in a lot of races on it. The bike has been sitting gathering dust in shed on a farm for around 30 years and rarely ridden since I stopped racing. I plan to do a restoration job on it!
My 77yz80D is going to be for sale. Owned it since I was 9. Still have the pink slip too. So clean and faster than alot of the competition even later years.
I just got my 1974 YZ 80 out of a storage unit. I know this video is old but it sure brought back memories. I got this motorcycle for my birthday when I was 7. I signed up with the AMA and started racing the girls powder puff class. My Dad painted my helmet to match the silver and black. And he duct taped a pink bow on the back of it. I was hell on wheels then. I have all the parts I am going to put this thing back together again. The pic you have in the video will help a lot. Thanks.
I have the 1984 and holy shit do they go
I have the 83, all striped down, total rebuild I’m doing. Also the 84 bike I’m going to rebuild, this video has helped thanks, just finding the parts in the UK in not good
As usual, good job! :)
Czarekkx60 DirtBikeJunior Thank´s! :)
Great video.....Thanks...
ROBERT WEIR Thank´s :) and subscribe for more if you want to ;)
Didn't see the 79 f. F had white Yamaha on the side of the seat
Had them 76’ - 80’ 🍻
good job :)
+Colby Coakley Thank´s man! :)
i just picked up an '84 yellow basket case, redoin it..it looks killer so far
I just picked up an 83 basket case. Haven't started on it yet.
thinking of getting a 1998 yz80 is that a good purchase?
How about the 80s yz? Is it the same 2stroke from 74 to 01?
Buying my first ever bike tomorrow 01 yz 80
First bike ever huh? Congratulations! I hope you're enjoying it so far! There's nothing like it
@@Jaybiv dude I absolutely love it. The dirt is sketchy so I'm going to sell it and try and her a street bike. 2 wheels for life ahaha
How much were they new in 1993
Anybody know which year(s) the YZ80 had a metal gas tank? I'm tryin' to nail down the year of the YZ80 that a friend of mine taught me how to ride on back in '79 or '80 but his bike was used so I know it wasn't a '79 or '80. I also know it wasn't a '74 because his was yellow. I seem to recall that his did have a metal gas tank. I would ask him but he's not around.
It might be a year to late to answer your question but the YZ 80 F was the last of the metal tanks the YZ80 G went to plastic . the year was 1978 or maybe 1979 but i pretty sure its 1978 . I had one in Australia and they were white over here not yellow like America ,. Best bike i ever owned when i was a kid .
Yes the 78 and 79 was the last years for the metal tanks .... i had the 1982 with the first year of the water cooler. My best friend had the 1979
Why so many mods and even faulty gears and clutch springs ? Early bikes from 70s and 80s never had these issues
My favorites are 1986 84 87 and 2001
I have the 2001!
I've got a 1994 and it's the fastest 80 I own or have rode
I had a 93 i wish I would of kept
i have a 83 and it is a rocket.. but mines yellow and black...
I just finished restoring a 1982 YZ80J with a 5X2 engine. It runs like new.
I just finished restoring a 1982 YZ80J with a 5X2 engine. It runs like new. I never change the gear box oil cause I don't know whats recommended. Its filled & clutch has no problems grabbing.
I have 1983
Only thing, you wrote the 1979 as a 1970. :-)
+AjackLee4 Thank´s i corrected it :)
The 1990 one is one I rebuilt in 2014, see it here www.motorcyclerenew.blogspot.com and the progress.