yamaha porting book

[bcredneck]

i figered some of you guys would like to port your own motor but are scared of messing up your motor so i borrow this book i will be getting more and better pics later tonight but this is basicly whats in it
edit: contrary to what VAhuffie said page 161 to 163 are non motor specific most info on thease pages can be helpfull to most 2 strokes please dont make negitive coments unless you read thouse pages some other pages contain info that is also non motor specific what you do with this info is your choice do not compain that some one was nice enough to make this book avalible online as you wont find it anywhere else ive checked

http://www.3wheelerworld.com/attachment.php?attachmentid=115765&d=1296767675
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[HuffieVA]

"Piston port induction" is an alternative to reed valves on a 2-Stroke, so its not necessarily a book on porting but on "Piston Port Induction" engined bikes like the Yamaha AT 125's and I believe early YZ's and MX's (other companies as well, Rotax used it longer than anyone else I think) prior to the reed valve engines becoming popular, smiler configuration to that of a chainsaw cylinder. It may have some "porting" suggestions but they would be engine specific to the models covered in the book... (What I'm saying is, don't take that book, grab a Dremel and start hacking away at your Tri-Z cylinder, you will not be happy with the results)

[bcredneck]

you have no idea what your talking about theres even info on what reeds to use in the book have you even seen a old yz motor

[bcredneck]

unless i imagind this but then it would have been hard to get this pic
http://www.3wheelerworld.com/attachment.php?attachmentid=115775&d=1296771196

[HuffieVA]

you have no idea what your talking about theres even info on what reeds to use in the book have you even seen a old yz motor

Yea Smartass, I currently have:

1970 AT125, 1973 AT125, 1974 DT125, 1978 YZ250 (reed valve engine) in my garage

and have formerly had

75 DT400 and several 80's and 90's YZ's

Now before you make yourself look foolish read the back cover of the book where it lists the models that the book applies to:crazy:

If the back cover is missing, Ill send you a picture of my copy, would you like to see the 80 - 175cc version as well?

Yes there are still ports in a reed valve two stroke, but you have a model specific repair book, not a guide to porting...

Ill accept your apology in advance:D

[bcredneck]

there are no 125s in my book

[HuffieVA]

But by all means feel free to go out and ruin your port timing by using the wrong book...

[HuffieVA]

there are no 125s in my book

Probably because its for 250 - 400, get your panties out of the wad their in and look at the back cover

[bcredneck]

some people like to get at least basic info on what there doing it also expains basic tuneing and alot of other helpfull stuff people would like to know if you dont whant to read it then look at a differnt thead i didnt come on here to argue with you im posting for people who would like some basic info on porting

[HuffieVA]

Yes its called a repair manual, I was just letting you know that it does not explain the art of high performance two stroke porting like you originally thought (or at least sort of stated), it wasn't to argue with you, just make sure you didn't go out and start grinding away at the ports on your trike or someone elses for that matter... With that being said, there are some good books out there on porting, its just that this is not what this particular book was written for

[bcredneck]

it expains quite alot i just dont have thous pages on here yet im working on getting update: there here now

[bcredneck]

i used this book on a 75 yz 250 but after i was done the owner filled it up with striat gas and took it for a rip so i never got to ride it

[RubberSalt]

I entered the information for the 250cc for image 25 in my program here. It's actualy not to bad on the timinings. 184.4 exhaust duration, 117.4 on the main transfers, 122.2 on the aux transfers, 119.8 on the boost port. This gives a blowdown of 31.1 degrees. Most ported engines have 30-35 degrees of blowdown. This is the time from when the exhaust opens to when the transfers open. This is somewhat similar to what i run on my trikes.

And that book does explain port modifications for more power, it's not just a repair manual. On page 8, in the first picture posted here, it states that it gives demisions for maximum power, this is more than stock... lol read the book before you say what it is not :-p

[bcredneck]

i thought you might like this

[RubberSalt]

I wounder what is in the 80 - 175cc. I really want to see how close I am to yamaha on the 175 stuff lol

[bcredneck]

i was told you can do the math and scale these plans down to work on a different motor but im not shure it would work

[HuffieVA]

lol read the book before you say what it is not :-p

Read the thread before you jump to conclusions, I said that this book is model specific, and what "piston port" meant in the context of the book title... It is a good book for its application, but it is not an overall porting guide, yes it mentions it, it also tells you how to remove the master link on your chain... so it is a basic do it yourself repair manual that touches on a lot but doesn't give any overly in depth information... as for being "close to what Yamaha says" on your 175 I'd be happy to scan the related pages in that book for you but again, its not what "Yamaha" says its what "Clymer" says.... if you want to begin to read an in depth explanation of porting and how it works, try something like this:

http://www.amazon.com/Two-stroke-Tuners-Handbook-Gordon-Jennings/dp/0912656417

I'm not sitting here claiming to be an expert, but I can tell you that "Bob Vila's guide to porting and polishing" (i.e. the Clymer Manual) is not the answer to everything...

Now I'll let you kid argue amongst yourselves, and remember your premix, "after a top of the line porting job" he didn't realize it was a smoker? and his mechanic didn't tell him?

Good luck with your Dremels

[bcredneck]

please do some more reading before you post again

[bcredneck]

and i wasent there for the test ride on the yz250 or i would have said something

[HuffieVA]

Look Kid, what you need to do is read the back cover of the book and compare it to what you said in your first post in this thread...
Furthermore since you want to be technical, your supposed "Porting Bible" covers piston ported Yamaha 2 strokes from 68 thru 76, Yamaha didn't sell there first Tri-Moto until 1980 which was a 125 they later had a 175 (both not in your book and a different design of intake system) Yamaha didn't have a 250 trike until 85 some nine years after your "How To" book stops, I'm not saying you don't have a good reference book, just that it is not what you think it is... Yes it has a brief explanation of porting but it is not any type of definitive guide that covers every Yamaha two stroke ever built, the basic theory is the same but the application is different... Look I know you intended to provide some good info, and you did, but you were just a little off in your explanation of what it was... I didn't jump all over you but simply tried to explain what you actually had, you went off on a tangent, You can continue to argue if you wish but that will never change the actual contents of the book will it?

[bcredneck]

stop posting on this thead you started out by saying that the motors didnt have reeds then this was a repair book and not for porting now you say the info is useless whats next

[HuffieVA]

stop posting on this thead you started out by saying that the motors didnt have reeds then this was a repair book and not for porting now you say the info is useless whats next

You really are thick headed aren't you man...

Here is an explanation for you...

http://ezinearticles.com/?Two-Stroke-Induction&id=395744

As far as the existence of reeds go, read your book a little bit more and you will notice that the earlier models that it covers are reedless and true piston port induction, they went from that to a combo and finally to true reed induction later (this is why your book stops at at 1976), that is a repair book, and if you would have actually read my post I didnt call your info useless just specific to the engines the book covers, those particular engines were never put into trikes as Yamaha didn't introduce the Tri-Moto until four years later in 1980, and it was not above 200cc's (another reference to the specific engines your book covers)

I'm sorry you cant comprehend what I was trying to tell you, but apparently its not going to click until you screw up a valuable cylinder thinking in your mind that your some kind of reincarnation of Klemm Research, rather than a kid that simply misunderstood the title of a book thinking that it was a masters guide to high performance two stroke porting...

It appears from some of your spelling that there may be a connection to what you actually read and what it actually means

So I ask you these simple questions:

Are the early engines in your book reedless?
Does your book give directions on how to repair the engines it was written about?
Do the diagrams showing porting represent a particular model of engine?

If you answered yes to these questions you agree with me, if you answered no, well then your lying to yourself at this point so if your done making a fool out of yourself, stop it because you have already done a heck of a good job.

[WIkid500]

Here ya go Boys. 2 stroke tuners hand book. Quit bickering and start reading, you might learn something....


http://www.vintagesleds.com/library/manuals/misc/Two-stroke%20Tuner's%20Handbook.pdf

[HuffieVA]

Here ya go Boys. 2 stroke tuners hand book. Quit bickering and start reading, you might learn something....


http://www.vintagesleds.com/library/manuals/misc/Two-stroke%20Tuner's%20Handbook.pdf

Thanks, that's the one I linked to in post #17:D

[bcredneck]

the reedlees motor are not incuded in the perforance section of the book it even says to mod a motor you should get them i have i posted it to give people a basic idea on porting i never told any one to start grinding there jugs and pistions down and i didnt find that link after a few hours of looking so i whent out and found the best info i could find and there are people who own these bikes on this site that could use thous diagams i posted

[HuffieVA]

"i figered some of you guys would like to port your own motor but are scared of messing up your motor so i borrow this book i will be getting more and better pics later tonight but this is basicly whats in it"

Sounds like you were gonna show the world how to port to me?.?.

"contrary to what VAhuffie said page 161 to 163 are non motor specific most info on thease pages can be helpfull to most 2 strokes please"

Hey BC your right the description of how a basic two stroke functions and what theories are used to increase power are indeed not exactly model specific...
I Wholeheartedly apologize...

"nice enough to make this book avalible online as you wont find it anywhere else ive checked"

Ya didn't check too hard, there are almost 40 copies on eBay right now...

http://motors.shop.ebay.com/i.html?_nkw=yamaha+piston+port+manual&_sacat=&_odkw=yamaha+porting&_osacat=0&bkBtn=&_trksid=p4506.m270.l1313

Hey sorry I broke your heart by not agreeing with your original statements about this "Tell all Book" and by the way, this never would have gotten out of hand had you not followed up with your smart ass comments, so go ahead and edit your previous comments a little more, or we could just drop it, as it sounds like you finally understand what the book is, now your confused about how to cover up the fact that you were a little off in the beginning...

I'm all for sharing info and constructive criticism, but when you make a questionable statement, and try to mold it around an answer after you realize you were wrong in the first place I've got little use for ya, anyway, buck up lil camper chances are you've got a bright future, its just doubtful it'll be in high performance two strokes... unless of course you update your reference library

[fabiodriven]

http://www.hookedonphonics.com/

[bcredneck]

ive said countless times this can give you >>>basic<<< info on porting and it dose im done arguing about it

[HuffieVA]

http://www.hookedonphonics.com/

I'd be willing to foot the bill, if you think he'll go through with it...

[HuffieVA]

ive said countless times this can give you >>>basic<<< info on porting and it dose im done arguing about it

I'll give you that, but only if you start counting "After" you edited your original post...

[bcredneck]

if popele can undrestnad waht i say i dnot care abuot splelnig

[Ironbnder]

Your post are always captivating but if you would invest in some punctuation, I would not have to read them 2 and 3 times to interpret the meaning.

[ailll1]

^^I second that, If I can't understand after a first reading what you wrote means, I just won't read it at all.

[dcreel]

^^I second that, If I can't understand after a first reading what you wrote means, I just won't read it at all.

Yeah but.. How can you not read it, if you've already read it? Can you hear me now..? :lol:

[NINJA]

Wait a second, is this James9r9? :lol:

[ailll1]

Yeah but.. How can you not read it, if you've already read it? Can you hear me now..? :lol:

Man, You're hard on my brain! Let's just say I won't lose my time on PARTS that are hardly understandable.;)

[oscarmayer]

interesting, I read again and found what I was looking for. According to the manuals, Yam in 72 made a 250cc enduro engine. claymore is NEVER wrong...... (hundreds of blown honda civic engines later they still have NOT adjuted their torque values for the head, camshaft and other stuff. even though we sent them actual photos of a real factory service mnaual and went all the way to the VP of technologies.).

[2Tim215]

http://www.hookedonphonics.com/
Sorry, but that was mean!!!

[bcredneck]

interesting, I read again and found what I was looking for. According to the manuals, Yam in 72 made a 250cc enduro engine. claymore is NEVER wrong...... (hundreds of blown honda civic engines later they still have NOT adjuted their torque values for the head, camshaft and other stuff. even though we sent them actual photos of a real factory service mnaual and went all the way to the VP of technologies.).
??????????

[Billy Golightly]

Valiant effort. Execution needs some more work.