Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > Yamaha Tech
Engine difference – 3TB vs 4PT Engine difference – 3TB vs 4PT
Register FAQ Calendar Today's Posts
Yamaha Tech Originally the Yamaha XT600 Tech Forum, due to demand it now includes all Yamaha's technical / mechanical / repair / preparation questions.
Photo by Hendi Kaf, in Cambodia

I haven't been everywhere...
but it's on my list!


Photo by Hendi Kaf,
in Cambodia



Reply
Page 2 of 2 1 2
 
LinkBack Thread Tools Display Modes
  #16  
Old 17 Apr 2016
Registered Users
Veteran HUBBer
  
Join Date: May 2013
Location: Wisconsin, USA
Posts: 827
I found different combustion chamber sizes on the older bikes when the hp ratings changed , could very well be they opend them up a bit more or made the ports a little different size , doesn't take a whole lot if done to the right places. A person would need to have one of each head side by side and measure all aspects.
Reply With Quote
  #17  
Old 18 Apr 2016
Registered Users
Veteran HUBBer
  
Join Date: Dec 2008
Location: Denmark
Posts: 1,417
My 2003 model dynoed 34,6hp on the rear wheel with the snorkel removed, and a new exhausttip, and i think a pipercross airfilter. At that point it had over 50.000km on it, so perhaps the powermods just about made it up for the wear in the engine...

My friends ktm640 dynoed with a 10hp loss from the stated HP at the crank, to the actual meassured rearwheel-hp. If it's the same for the xt600, you would be very close to 45 hp on the crank
Reply With Quote
  #18  
Old 18 Apr 2016
xtrock's Avatar
Registered Users
Veteran HUBBer
  
Join Date: May 2013
Location: Norway
Posts: 1,371
True Rear Wheel Horsepower

The SRX is the same engine. Who knows, maybe its all in the exhaust, maybe you got the 44hp when open up with more air and new exhaust.
Reply With Quote
  #19  
Old 9 May 2016
Registered Users
New on the HUBB
  
Join Date: Feb 2011
Location: Northern Scotland
Posts: 16
Valve shrouding
On my 2001 E , the valves were badly masked by the sides of the combustion chamber even at full lift. I marked around the head gasket and opened the head away from the valves. It made a real difference.
Reply With Quote
  #20  
Old 9 May 2016
xtrock's Avatar
Registered Users
Veteran HUBBer
  
Join Date: May 2013
Location: Norway
Posts: 1,371
Quote:
Originally Posted by frozenbiker View Post
On my 2001 E , the valves were badly masked by the sides of the combustion chamber even at full lift. I marked around the head gasket and opened the head away from the valves. It made a real difference.
Ok, so what you mean by badly masked? BTW i tested a 4pt with leo vince against 3tb and it seems similar, in my head it should have been a much bigger difference so i bet the exhaust makes less hp or it never was any less output on the 4pt.
Last edited by xtrock; 9 May 2016 at 11:28.
Reply With Quote
  #21  
Old 9 May 2016
Registered Users
Veteran HUBBer
  
Join Date: May 2013
Location: Wisconsin, USA
Posts: 827
He means the combustion chamber is closed over somewhat around the outside in a portion of the valves , valves can't "breath" fully. Think roof. The XT's aren't that bad , similar to most . The head gasket need to be shaped so they don't stick into the combustion chamber. My klx650's are horrible and 6-8hp gains can easily be had by going 2mm overbore and grinding the chamber open around the outside of the valves to match the 2mm bigger bore.

I haven't seen any of the newer heads to know if they changed the shape , that could easily loose several hp.
Reply With Quote
  #22  
Old 9 May 2016
xtrock's Avatar
Registered Users
Veteran HUBBer
  
Join Date: May 2013
Location: Norway
Posts: 1,371
danimalu if you remove head again you can take a picture.
Reply With Quote
  #23  
Old 11 Jun 2016
Registered Users
Veteran HUBBer
  
Join Date: Jan 2012
Location: North London
Posts: 102
Has the 3tb a big valve head ?

Cheers
Min
Reply With Quote
Reply
Page 2 of 2 1 2

« Previous Thread | Next Thread »

Currently Active Users Viewing This Thread: 1 (0 Registered Users and/or Members and 1 guests)
 

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Engine numbers on bike titles? srileo Trip Paperwork 7 21 Nov 2019 21:19
1VJ and 3TB front fork mix? svakak Yamaha Tech 0 4 Feb 2013 19:07
3TB - 4PT Cases w00d Yamaha Tech 15 13 Feb 2012 21:59
XT600E 2002 Engine Oil Trichelia Yamaha Tech 17 17 Nov 2011 15:25

 
 

Announcements

Thinking about traveling? Not sure about the whole thing? Watch the HU Achievable Dream Video Trailers and then get ALL the information you need to get inspired and learn how to travel anywhere in the world!

Have YOU ever wondered who has ridden around the world? We did too - and now here's the list of Circumnavigators!
Check it out now, and add your information if we didn't find you.

Next HU Eventscalendar

25 years of HU Events
Be sure to join us for this huge milestone!

ALL Dates subject to change.

2025 Confirmed Events:

Virginia: April 24-27 2025
Queensland is back! May 2-4 2025
Germany Summer: May 29-June 1 2025
CanWest: July 10-13 2025
Switzerland: Date TBC
Ecuador: Date TBC
Romania: Date TBC
Austria: Sept. 11-14
California: September 18-21
France: September 19-21 2025
Germany Autumn: Oct 30-Nov 2 2025

Add yourself to the Updates List for each event!

Questions about an event? Ask here

See all event details

 
World's most listened to Adventure Motorbike Show!
Check the RAW segments; Grant, your HU host is on every month!
Episodes below to listen to while you, err, pretend to do something or other...

Adventurous Bikers – We've got all your Hygiene & Protection needs SORTED! Powdered Hair & Body Wash, Moisturising Cream Insect Repellent, and Moisturising Cream Sunscreen SPF50. ESSENTIAL | CONVENIENT | FUNCTIONAL.

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

"Ultimate global guide for red-blooded bikers planning overseas exploration. Covers choice & preparation of best bike, shipping overseas, baggage design, riding techniques, travel health, visas, documentation, safety and useful addresses." Recommended. (Grant)



Ripcord Rescue Travel Insurance.

Ripcord Rescue Travel Insurance™ combines into a single integrated program the best evacuation and rescue with the premier travel insurance coverages designed for adventurers.

Led by special operations veterans, Stanford Medicine affiliated physicians, paramedics and other travel experts, Ripcord is perfect for adventure seekers, climbers, skiers, sports enthusiasts, hunters, international travelers, humanitarian efforts, expeditions and more.

Ripcord travel protection is now available for ALL nationalities, and travel is covered on motorcycles of all sizes!


 

What others say about HU...

"This site is the BIBLE for international bike travelers." Greg, Australia

"Thank you! The web site, The travels, The insight, The inspiration, Everything, just thanks." Colin, UK

"My friend and I are planning a trip from Singapore to England... We found (the HU) site invaluable as an aid to planning and have based a lot of our purchases (bikes, riding gear, etc.) on what we have learned from this site." Phil, Australia

"I for one always had an adventurous spirit, but you and Susan lit the fire for my trip and I'll be forever grateful for what you two do to inspire others to just do it." Brent, USA

"Your website is a mecca of valuable information and the (video) series is informative, entertaining, and inspiring!" Jennifer, Canada

"Your worldwide organisation and events are the Go To places to for all serious touring and aspiring touring bikers." Trevor, South Africa

"This is the answer to all my questions." Haydn, Australia

"Keep going the excellent work you are doing for Horizons Unlimited - I love it!" Thomas, Germany

Lots more comments here!



Five books by Graham Field!

Diaries of a compulsive traveller
by Graham Field
Book, eBook, Audiobook

"A compelling, honest, inspiring and entertaining writing style with a built-in feel-good factor" Get them NOW from the authors' website and Amazon.com, Amazon.ca, Amazon.co.uk.



Back Road Map Books and Backroad GPS Maps for all of Canada - a must have!

Your ad could be here, on EVERY page of the HUBB, or the whole website, or as many as you like!

New to Horizons Unlimited?

New to motorcycle travelling? New to the HU site? Confused? Too many options? It's really very simple - just 4 easy steps!

Horizons Unlimited was founded in 1997 by Grant and Susan Johnson following their journey around the world on a BMW R80G/S.

Susan and Grant Johnson Read more about Grant & Susan's story

Membership - help keep us going!

Horizons Unlimited is not a big multi-national company, just two people who love motorcycle travel and have grown what started as a hobby in 1997 into a full time job (usually 8-10 hours per day and 7 days a week) and a labour of love. To keep it going and a roof over our heads, we run events all over the world with the help of volunteers; we sell inspirational and informative DVDs; we have a few selected advertisers; and we make a small amount from memberships.

You don't have to be a Member to come to an HU meeting, access the website, or ask questions on the HUBB. What you get for your membership contribution is our sincere gratitude, good karma and knowing that you're helping to keep the motorcycle travel dream alive. Contributing Members and Gold Members do get additional features on the HUBB. Here's a list of all the Member benefits on the HUBB.



All times are GMT +1. The time now is 11:03.

Contact Us - Horizons Unlimited Motorcycle Travellers Website - Archive - Privacy Statement - Top