What's the performance difference between an 86 tri-z and a 85?

[350xman]

Hi Guys
I have a question for all of you tri-z guys. I was reading in the old dirt wheel magazines that a stock 86 tri-z had more power and better acceleration than a 85 tri-z, is this true? Does anyone out there know if stock 86 is better than stock 85 tri-z for motor preformance and handling? How much of a difference is there, are the power bands quite a bit different or not? Does the 86 tri-z hit alot hard in its power band than the 85? I haven't had a chance to ride a 85 and compare it to an 86.
Later
350xman

[1984kxtTECATE]

I will be getting an 85 Z on the 21st as you know, I know the 86 has a 6spd tranny compared to the 85's 5 spd. I also heard that the 86 Z has different forks I am assuming travel and what not. I am no Z expert and would also want more info about the differences about the two years.

[TrikerR]

differences

86: 39mm front forks, 10.00 inch travel. 6 speed transmission. and im sure the coolant over flow tank is in a different location. the rear also gains about .6 inch more travel.

[Darius1502]

Some who have originals of both say its a significant difference. I know I hear alot of folks complain about the 85 forks and power....

I ride my 86 and don't have any of these concens. Yes they are better!!

[Kintore]

Here is something that I will think you will find useful. I copyed it from some member a while back. Here it is

Old Yamaha press release information detailed in ATV News magazine 12/85:

1) Smaller intake port area
2) 6 speed transmission
3) bigger airbox intake tract (thats why the coolant resevoir is on the left side on the engine in '86)
4) completely different jetting on the 32 mm Mikuni carb
5) Smaller front tire6) Rake pulled in .05 degrees (with the smaller tire this adds to a shorter rake of 1.02 down from 1.4 inches
7) Lower profile Dunlop 21X11X9 inch tires
8) 39mm telscopic forks (verus 35mm)
9) Close to one inch more travel up front (10 inches)
10) Increased travel at the rear of 1.2 inches for a total of 9.3 inches
11) Increased compression and rebound damping adjustments
12) Red and White color scheme
13) New piston shape
14) Revised porting for more power

[Mike_Ham_250R]

I will be getting an 85 Z on the 21st as you know, I know the 86 has a 6spd tranny compared to the 85's 5 spd. I also heard that the 86 Z has different forks I am assuming travel and what not. I am no Z expert and would also want more info about the differences about the two years.
Hit the nail on the head :D

[Darius1502]

I think I posted all that stuff from my ATV News about 1.5 years ago....alot of changes...

[CHAINSAW]

The suspension you do notice a difference on, but its nothing that would persuade me to buy one over the other. However, the 6 speed tranny does make it nicer zipping across the dunes. With either 85 or 86, you cant go wrong with a Z!! :)

[350xman]

Thanks for the replies guys. I have a chance to pick up a 85 tri-z for a not bad price but if the 85 tri-z doesn't perform as well as a 86 tri-z then I might not buy it. Does anyone know stock 86 vs stock 85 tri-z how much quicker is the 86 tri-z then the 85 in drag races 0-100 yds and 0-250 yds? Is it(86 tri-z) like 3/10 of second or a whole second faster. I know it depends on the driver but if you had the same drivers changing off bike how much quicker is the 86 tri-z? Does the 86 tri-z power band hit alot hard in the low , mid or high end?
Anyways, I am having a hard time to decide if I should buy it or not because of the possible performance difference. I already have an 86 tri-z and like it. The guy that is selling it is a 150 miles away but he works on a offshore oil platform and is gone 3 weeks out of the month and is hard to match our scheludes up. So, that's why I am asking anyone who knows how these bikes perform against each other.
I ll just have to decide in the next day or two.
Later 350xman

[chris200x]

If you say you can get the 85' for a good price then why not get it? I would jump on it if I were you. Nothing a diffrent pipe and some sprocket changes can't fix.

[TimSr]

Ive seen and read the articles on the 86 motor performance, and I dont understand how they come up with it. Every part on the engine itself is interchangeable other than the tranny internal parts. Im baffled as to how there can be a porting difference since the cylinder head and piston use the same part number for both years. The only thing I can come up with is if they wrote about it before it was produced or the revised 86 part became the standard factory replacment parts for the 85's. Ive held both cylinders side by side, and there is no difference. Ive used them interchangeably and there is no difference in performance.
Its my understanding that the air intake was routed different which is the only logical reason I can think of as to why they used different jetting on the same motor. Im really baffled as to how they managed to get noticeable horsepower improvements on the same motor. If they are seeing more HP from an 86, then they managed to somehow gain it from the intake setup, or something else external to the motor. Different exhaust maybe?

I have an 86 motor on my 85, and I can confidently say there is no difference in the power between the motors, and only the gearing is different. The only motor parts that are not interchangeable are the gears, shifting forks, and shift drum.

As for handling differences, they use the same frame, and change the rake only by changing tire sizes. Thats what I call an adjustment, and not what I would call an engineering breakthrough. The 86 has bigger fork tubes, so if you bend a lot of forks, it might be an advantage of durability. A simple $72.00 spring change makes the 85 forks perform superior to the stock 86 ones.

While there are lots of minor differences, I dont feel any of them are outrageoulsly significant other than the tranny change. Is the 6 speed better? Depends on what you use it for. The 6 speed has a wider spanning range. It can both start a little lower and end a little higher. On the downside, the 6 speed gears are spaced closer together than they need to be for that motor. It means more shifting. I prefer the 6 speed for trail riding, so Im never in that place where one gear is too low, and the next one is too high. For MX racing, the 5 speed is much better. Less shifting through the same range of speed = better lap times. I know mine were. Id expect to see the same results from drags at normal length drag strips. For sand running the closer gearing of the 6 speed might be better in the upper gears but I cant see it being any advantge in the lower gears.

So if you are shopping for a TriZ, my advice is that youll be happy with either one, and since tires, exhausts, and air filters being used now usually arent stock anyways, I doubt your going to find enough performance difference to be disappointed in the 85's which are a lot easier to find.