Question about 1988 Yamaha FZ 600

1 Answer

Octane Well I have been doing some research, not always a good thing, and I think I may have stumbled upon something. I recently did an ignition upgrade( on my FZ 600 this has helped with fouling sparks plugs. After the uprgade I went to stock jets 60 and 115. The engine just wouldn't pull past 7,000 rpms. This bike is supposed to have peak power 36hp@10,000rpms. So i changed the jets to 60 and 105s and has definetely been running stronger. However I still don't believe i should be that far off on carb settings. I have been using 93 octane gasoline. I then read something interesting, that low octane gas burns faster and leaves fewer deposits, and that low octane is good for low compression engines, my bike 9.5:1 not sure how high that rate is? What do you think about the idea?

Posted by on

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert whose answer got voted for 500 times.

  • Master
  • 2,336 Answers

I don't know if the octane makes that much of a difference. I don't know if it's because I'm cheap or what but I've always ran 87 octane in my 350 and they seem to like it. They also pull all the way to 10K with no problems. The ignition upgrade you did was that the one running power from the key source to the coils? Just remember not to leave your key on to long with out the bike running. Constant power to the coils is known for burning them up. Done this a few times on cars. Good Luck!!!

Posted on Nov 10, 2008

1 Suggested Answer

  • 2 Answers

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

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.

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


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



Related Questions:

1 Answer

Stumbling and stallin 2003 Harley RK with Big Bore and stock cam.

Hi Anonymous, and the usual suspects are:
1. Spark plugs in bad condition or partially fouled.
2. Spark plug cables in bad condition or leaking.
3. Spark plug gap to close or to wide.
4. Faulty ignition coil, module and or sensor.
5. Battery nearly discharged.
6. Damaged wire or loose connections at battery terminals,
ignition coil, or plug between ignition sensor and module.
7. Intermittent short circuit due to damaged wire insulation.
8. Water or dirt in fuel system, carburetor or filter.
9. Fuel tank vent system plugged or carburetor vent line closed off.
10. Carburetor controls misadjusted.
11. Damaged carburetor.
12. Loose or dirty ignition module connector at crankcase.
13. Faulty MAP, CKP, and or CMP sensors.
14. Incorrect valve timing.
15. Weak or broken valve springs.
16. Damage intake or exhaust vale.
For a prime suspect please visit website below:
Good luck
Big Twin Carb EFI DTC Intructions codes Harley Davidson Forums Harley...

Jan 18, 2014 | Harley Davidson Motorcycles

1 Answer

2009 Harley fat bob, pings upon acceleration

Hi Jack, and the usual suspects are:
1. Fuel octane rating too low.
2. Faulty spark plugs.
3. Incorrect spark plug for the kind of service.
4. Excessive carbon deposit on piston head or in combustion chamber.
5. Ignition timing advanced due to faulty sensor inputs (MAP, CKP, CMP)
Good luck.

Mar 06, 2012 | 2006 Harley Davidson FXDBI Street Bob

2 Answers

When i change the oil for my 1998 honda cb400 super four should i also change the oil filter? is 92 octane fuel enough or would it cause my engine to ping? should i just use 95 octane?

The oil filter should be changed everytime the oil is changed. Filters get dirty and slow the flow of oil to get to the parts that need to be lubricated and cooled. Oil and filters changed often will keep your machine shop free longer. As for the octane I would stick with manufacture specs.

Apr 19, 2011 | Honda Cb 400 Super Four Motorcycles

1 Answer

Triumph Trophy 900 sounds top endy when accellerating hard. They tell me that this is normal. Engine sounds fine when ticking over with no unusual sounds.

I disbelieve what "they" are telling you however, if this sound is abnormal to you and has drawn your attention to it then I'd say it's your bike telling you there is something wrong.

I've worked on engines for almost 50 years now from 1 to over 700 horse power they all talk to someone that listens and understands the sounds sort of a mechanical language.

Here are a few of the things the engine may be telling you.
Pre ignition would be my first guess without hearing the sound myself, this is an easy fix by using a better grade of gas with a higher octane rating. I have in the past carried small pre measured containers of octane boost and dump one in the tank at each fill of 87 octane gas.
If your pump gas is below 87 then that's the problem and if yo do nothing about pre ignition it'll destroy the pistons and the engine if left.

Another thing is one or more valves out of adjustment "hydrolic lifters" or not they do get sloppy and could be due to poor oil, wrong oil viscosity/grade, just worn out engine oil needing a change that fix isn't a total fix but changing to a better quality oil check your manual to see what is recommended, not all engine oil is created equal.

Another thing is the overhead valve system is driven by a chain, this chain has a tension-er and if it's worn this chain becomes loose and will rattle in there something real bad. Not only that because of the slack in the chain it will alter the valve timing which will no doubt affect the engine performance and possibly cause pre ignition. If this chain is loose and not serviced it will brake and I've seen them where they had almost cut the engine into two pieces.

So you got pre-ignition, poor oil, cam chain or even to lean a gas mix at high speed which will cause pre ignition as well.

Apr 04, 2011 | Triumph Trophy 900 Motorcycles

2 Answers

What octane level of gas should I use for a 2003 Honda Shadow ACE

Usually premium (92 octane). That's what the bikes are designed to run on. Sometimes you can get away with using 89 octane. But try your best to never use 87 octane fuel, unless you're stuck somewhere and that's all you have available to you.

Oct 29, 2010 | 2003 Honda VT 750 CD Shadow A.C.E. Deluxe

1 Answer

99 gsxr carbs running to rich, idle screw thinking is the problem how do i adjust>

Most if not all manuals will tell you not to touch this...probably for a good reason. BUT, theres a few rules to this, each carb has one, you turn it out until the bike stumbles, make sure you know the count. Then you turn it in until it stumbles, also making sure to count. Then you simply turn it in/out so that it is between those two points. Sounds easy doesn't it...but its not always straight forward. Are all the carbs running rich? it is just a couple? Because if you synchronize them you may fix your problem and have a faster/better running bike. Another thing to consider is what air restrictions you have. If your bike is bone stock, as in, no modifications of any kind to the air intake or the exhaust, it might just be a plugged up air filter, not allowing enough air to get through. Or if you went from a modified piece to a stock piece that is more restrictive, that could have the same effect. I hope this helps.


Oct 21, 2010 | Suzuki GSX-R 600 Limited Editions...

1 Answer

My bike is cutting out its got 5700 miles on it is it the plugs maybe? is there a fuel filter on it tho its injection. some times when im trying to take of it dies. i goose it and it doesnt do anything it...

yes theres a fuel filter.
doubt its the plugs.
you dont need octane booster or even anything above 89 octane.
chances are you have a problem with the ignition coil(s).

Aug 08, 2010 | 2003 Suzuki SV 1000 S

2 Answers

2000 Suzuki vs800GL Intruder Engine stumbles

If you use a High octane gas, this may happen on the VL1500, You should only use regular Gas, and you will see a difference.

Apr 25, 2010 | 2002 Suzuki VL 1500 Intruder LC

1 Answer

Battery is draining while off, can push start insecond gear recently added octane boost??? suggestions?

adding the octane boost is no harm. . make sure battery is good, connections are good. it could be a small short, but unlikely for a newish bike

Aug 26, 2009 | 2008 Triumph Daytona 675

1 Answer


I think it is the stp octane that is making your exhaust smell. It is a different chemical besides gas going through the system. I think after you do the treatment once you should expect good gas mileage from your bike without another treatment. Isn't it made to clean the system. You don't need it every fill up do you? If you do, I don't think it's work the extra gallon of mileage it it? Wouldn't that equal like $10 per gallon for the stp octane booster, instead of the $4 per gallon we pay at the pump? Also is the stp made for bikes? Hopefully you aren't ruining something in your bike using it.

Nov 20, 2008 | 1994 Suzuki RGV 250 R

Not finding what you are looking for?
1988 Yamaha FZ 600 Logo

Related Topics:

320 people viewed this question

Ask a Question

Usually answered in minutes!

Top Yamaha Experts


Level 2 Expert

61 Answers

Steve Sweetleaf
Steve Sweetleaf

Level 3 Expert

1128 Answers

D. E. Hev

Level 3 Expert

1132 Answers

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

Answer questions

Manuals & User Guides