Question about 1980 Yamaha XS 650 G

1 Answer

Can't find compression specs for 1980 Yamaha 650G

Restoring this bike, I can't find what the compression should be. I ran a compression test and originally got 120 psi, then I put a little oil in the cylinders and got 240 psi. The engine will not pop with 120 but it did pop ( a little) with 240. Please help.

Posted by on

  • kirsten689 Jul 13, 2009

    Thanks for the tip. I dug in further, and the valves were adjusted wrong, the camchain was loose and the timing was off. Now I just have to rebuild the carbs, It's got Mikuni Kogyo carbs on it but no part number, very frustrating.

×

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Yamaha Master
  • 767 Answers

The compression should be around 150psi, but at 120psi it should pop, try to readjust the valve clearance.
Hope this helps!

Posted on Jun 21, 2009

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

1992 Yamaha XJ600 Diversion head compression number


Hi, Anonymous your bike runs a piston with a 10:1 compression ratio so your compression test should be around 160 PSI to perform a proper compression test you need a pressure gauge either threaded or push in. You will get a higher more accurate reading when the engine is at normal operating temperature along with burnt fingers if you are not protected or careful, cold testing works just fine and it the method I use 99% of the time. If your bike has cams and valves you need to make sure your valve clearance is within book specs Always blow forced air around the spark plug before you remove it to eliminate any uninvited contamination from getting inside the cylinder. Install the compression gauge, twist the throttle grip to the wide open position and kick or hit the starter button long enough for the engine to turn over 5-6 times. Record the reading and repeat the process 3 times to get the average reading. Single cylinder engines must have a minimum of 100 PSI anything less call a Priest for Last Rites, it's time for a top end overhaul. Multi-cylinder engines must have no more than a 10% difference between each cylinder, for you high- performance ******* no more than 10 lbs. per cylinder. To run on today's fuel most bikes have pistons with compression ratio's designed to give acceptable performance using 87 octane graded fuel, this means the average compression readings on most bikes will be 125-150 PSI. I have gotten readings of 200+ on some big inch V-Twins and Thumpers but these are rare #'s and require high octane fuel to eliminate cylinder ringing or "PING" For more information about your issue and valuable "FREE" downloads that you will need please click on the blue links below. Good luck and have a wonderful day.
xj600 1992 problems
Yamaha XJ600 Diversion Specs and Info WhiteDogBikes Blog
Yamaha XJ600S 1992 Service Manual
OEM parts for Yamaha
Yamaha Diversion XJ600N Owner Manual

Sep 08, 2012 | 1992 Yamaha XJ 600 Diversion S

1 Answer

Wiring diagram for a 1980 Yamaha XT250


How do you hot wire a 1980 xt250 dirt bike

Aug 16, 2012 | Yamaha Motorcycles

1 Answer

What is the compression spec on 1999 PW80


Hi, Trav696 for more information about your question and valuable "FREE" downloads that you will need please click on the blue links below. Good luck and have a wonderful day.
pw80 compression spec
1996 1990 2003 YAMAHA PW80 PW 80 ZINGER COMPRESSION TEST VIDEO
YAMAHA PW80 Owner Service Manual
OEM parts for Yamaha
YAMAHA PW80 Owner Manual

Mar 26, 2012 | 2004 Yamaha PW 80

1 Answer

I need a wiring diagram for a yamaha it175g 1980 model. I have diagrams but they don't include indicators, brake switches and the like. I have the Australian model bike which differs from the US model...


Hi, Mrkhlls for this scenario you will need your service/owners manual if you can't find the first and best tool you ever bought for your Yamaha, despair not, for a mere $24 you can download another one.
For more information about your issue and valuable "FREE" downloads that you will need please click on the blue links below. Good luck and have a wonderful day.
1980 yamaha it175g wiring diagram Google Search
Yamaha Motorcycle Wiring Diagrams
1980 Yamaha IT175G Motorcycle Owners Service Manual $24
OEM parts for Yamaha
80 81 IT175 Specifications

Sep 22, 2011 | Yamaha Motorcycles

1 Answer

How much fork oil for a yamaha xs 750e 1980. the 750e seems to be differant to the 750. Any help would be a great help Terry


G'day. When I'm in trouble with a fork oil quantity spec.I use the oil level method of setting up my forks. The spec. is an oil level of 105mm from the top of the leg with the fork fully compressed(spring removed of course).Works every time.
Hope this is helpfull
Regards Andrew Porrelli

May 04, 2011 | Yamaha XS 650 E Motorcycles

1 Answer

Cylinder head torque spec


I am not that familiar with the Yamaha but this is what I could find in my research, I also asked my husband who is a bit more familiar and he said either call the shop and see if they will provide the info or purchase a manual at the shop or online for your bike. I am providing you with the info that I found and I hope that it will help you in your endeavor as I know it can be very difficult to locate some info that you desperately need sometimes.. Thanks in advance and I hope it helps. See below. Stormi

Cylinder;The cylinder shaped space (obviously) in an engine where the piston moves up and down to compress and explode fuel, which generates the engine's power.

TORQUE:The tendency of a force to cause an object to rotate. In an engine, the torque is expressed as the force applied multiplied by the distance from the center of rotation. It is the basic measure of the propulsive effect of a powered wheel. Or, said in other words: The measure of the force applied to produce rotational motion usually measured in foot-pounds or Nm. Torque is determined by multiplying the applied force by the distance from the pivot point to the point where the force is applied.


Max Torque
5.5 kg-m @ 7500 rpm

The Yamaha XJ650, also called the Maxim 650, was part of the Yamaha XJ series of high-performance, cruiser-class motorcycles. Yamaha manufactured the classic-style street bike from 1980 to 1983. The Maxim's design and horsepower-to-weight ratio made it a precursor to the modern sport bike.

Engine
1. The 1981 Yamaha XJ650 Maxim was powered by an in-line 653 cc, four-cylinder, dual overhead cam engine with eight valves. The air-cooled, four-stroke motor used four 32 mm Hitachi carburetors. Its bore and stroke measured 2.5 inches by 2.1 inches with a compression ratio of 9.2:1.
Chassis
2. The Cardan shaft-driven Yamaha Maxim had a five-speed gearbox. The air-assisted 1-inch (26 mm) front forks had 5.8 inches (147 mm) of wheel travel. The five-way adjustable spring preload rear suspension had 3.8 inches (97 mm) of travel. The bike had a hydraulic single-piston, single-disc front brake with an expandable drum rear brake. The Yamaha XJ650 had a curb weight of 509.3 lbs with a seat height of 30.7 inches.
Performance
3. The Yamaha Maxim generated 71 horsepower at 9,400 rpm with 39.8 foot-pounds (5.5 kg-m) of torque at 7,500 rpm. The bike's quarter-mile time was 12.6 seconds at 107 mph. Its top-end speed was 120 mph.



Read more: Specs for the Yamaha Maxim Motorcycle ' eHow.com http://www.ehow.com/facts_7379753_specs-yamaha-maxim-motorcycle.html#ixzz15CI4IY6T

Nov 13, 2010 | 1981 Yamaha XJ 650

1 Answer

YAMAHA XS400SG (1980) In restoring this bike, I did not notice that the oil filter is flat on one side and indented on the other. Which side of the new filter faces the engine block - the flat side or the...


If you look at the schematic for the oil pump for your bike you will see it in the lower left hand side. (link to bike bandit below) It appears to me that the indention is facing OUT away from the motor. Look at yours and compare it to the picture to make sure. I hope this helps!

Bruno

http://www.bikebandit.com/houseofmotorcycles/1980-yamaha-motorcycle-xs400sg/o/m8261

Oct 21, 2010 | Yamaha XS 400 Special Motorcycles

1 Answer

Camchain specs on a 1980 maxim 650


Please visit this site www.xjbikes.com theres a lotof info there for our bikes!
Good luck.

( mine is Yamaha XJ750A '81)

Oct 10, 2009 | 1980 Yamaha XJ 650

1 Answer

Bike smokes when


Hey Alan, you did'nt say what mileage but i suspect high mileage on a 1980 bike. A compression test is easy on a 2 cylinder and will probably result in a low reading on the side that smokes. Also the chke could be closing tighter on the carb on the smokey side causing too much fuel to enter and also cause smoking....The short time you need to choke a bike in summer is a small price to pay on a bike that old...so ride and enjoy, you're not damaging anything by riding it that way...by the way, i love those old Yammer 650s...Good Luck to you friend.....Tim

May 09, 2009 | 1980 Yamaha XS 650 G

Not finding what you are looking for?
1980 Yamaha XS 650 G Logo

Related Topics:

356 people viewed this question

Ask a Question

Usually answered in minutes!

Top Yamaha Experts

dhnguyen

Level 2 Expert

281 Answers

Steve Sweetleaf
Steve Sweetleaf

Level 3 Expert

1144 Answers

Tony

Level 3 Expert

2600 Answers

Are you a Yamaha Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...