Wing tips #5

Tips and Recommendations from Guru Mike Nixon

Moderator: Whiskerfish

User avatar
mikenixon
Early 'Wing Guru
Early 'Wing Guru
Posts: 477
Joined: Thu Dec 10, 2009 1:51 am
Location: Prescott, AZ
Contact:

Wing tips #5

Post #1 by mikenixon » Wed Feb 28, 2018 11:16 am

When premium is not so, ah, premium
When a dealer mechanic in the 1970s, a Wing came in with an odd engine noise on rapid decel. I confirmed this as a very loud and increasingly sharp tapping when the throttle was yanked open then allowed to snap shut. Interesting. The customer insisted on disassembly, and the findings were very heavily carboned exhaust valves and faint witness marks on the pistons. Yup. There was so much carbon that on decel the valve's closing was slowed slightly and the piston actually kissed the valves, making the noise. The customer admitted to using premium gas. Fast forward almost 40 years, I'm training manager at Kawasaki corporate, and a dealer needed help with a bike because of an unsolvable high speed misfire. Upon disassembling the engine, we found something interesting, and it took me back to that aforementioned Gold Wing so many years before: heavily carboned exhaust valves. What was happening was the same as with the Wing. The valves were hanging open slightly at full rev. But in this case the bike's computer, sensing a cylinder compression change and programmed to protect the bike's catalytic converters, intermittently disabled the ignition system to do so, resulting in the misfire. Wow. Bet you didn't know vehicle ECUs were that fancy, eh? Here's the point. Using detergent and solvent laden premium fuel, really designed for crusty old cast iron V8s, is a bad idea for the relatively modern, highly combustion efficient Japanese motorcycle engine. In all but a very few exceptions, 87 octane unleaded is what the Japanese design their engines for.

Grandma on speed
I want to put what I said about K&N air filters into better perspective. When a mechanics instructor I used to have certain sayings with which I reinforced my instruction. One was "pressure differences, pressure differences, pressure differences!" This particular mantra -- and it became just that to my students -- reminded them of the underlying principle behind carburetion, and also electricity (more specifically, voltage), and a surprising number of other things covered in that six week long, five hour a day freshman-level introduction to the main technical disciplines within powersports mechanics. One of my favorite of these sayings though was, "...like putting your grandmother on speed." (What?!) I used to say this on several occasions, for example when we explored why it is bad practice to introduce to a battery a richer electrolyte solution than recommended. Because, I warned, though it might perk up a worn out battery, it would be like putting your grandmother on speed. The battery's useful life is fast-forwarded into a shorter period. There's a trade-off of performance at the cost of durability. It got their attention. And it's true. And it's true of K&N air filters as well. Your bike's engine has built into it X number of hours or miles that it will perform as designed while fed properly filtered air. But giving it bigger gulps by also allowing more contaminants in is simply using up that designed-in, normal lifespan in a bigger hurry. Like giving your grandmother amphetamines. This is my bone to pick with the K&N. It seems wasteful to me to trash any engine, but especially a historical, significant machine by deliberately accelerating its timeline in the name of "free performance". But here's the deal. If it's worth it to you -- and who am I to tell you what to do with your 40-year old motorcycle -- then great. More power to you. I just think you should know all the facts. Poor old grandma.

User avatar
Sandy
Silver Member
Silver Member
Posts: 887
Joined: Tue Jun 17, 2008 9:15 am
Location: Barrie, ON, Canada
Contact:

Re: Wing tips #5

Post #2 by Sandy » Wed Feb 28, 2018 11:48 am

Interesting Mike.
My concern is that I can only get zero ethanol fuel in the Shell super grade.
Every other brand and grade uses up to 10% ethanol.
Non of my GL's are ridden hard so what is best, zero ethanol or carbon build-up?

Also use K&N filters due to easy to clean as opposed to finding a replacement paper filter.
The 76 has been around since new with the K&N and has been using super since the first Randakk rebuild.

User avatar
mikenixon
Early 'Wing Guru
Early 'Wing Guru
Posts: 477
Joined: Thu Dec 10, 2009 1:51 am
Location: Prescott, AZ
Contact:

Re: Wing tips #5

Post #3 by mikenixon » Wed Feb 28, 2018 4:56 pm

Thanks for the comment, Sandy. Well, I can't argue with that.

User avatar
5speed
True Blue Steel Biker
True Blue Steel Biker
Posts: 2890
Joined: Sat Jul 11, 2015 2:37 pm
Location: Nova Scotia Canada

Re: Wing tips #5

Post #4 by 5speed » Wed Feb 28, 2018 7:10 pm

Good to know. I've been putting the high octane gas in mine..
I'll change to the regular gas this summer.

User avatar
Rednaxs60
Billet Alum. Member
Billet Alum. Member
Posts: 296
Joined: Mon Nov 30, 2015 11:14 pm
Location: Victoria, BC, Canada

Re: Wing tips #5

Post #5 by Rednaxs60 » Wed Feb 28, 2018 8:40 pm

Premium versus regular gas is always an interesting topic. Grew up in Barrie, Ontario. Ran snowmobiles for years and had friends that would use nothing but premium fuel, I always used regular 87 octane. Got the same performance and mileage as they did at considerably less cost. Only time I would use premium gas is when it warmed up and there was a probability of pre-ignition.

Use this same philosophy with my '85 LTD GW. Designed for 87 octane so I use it. Better and more complete burn in a lower compression engine. Only time I use higher octane gas is in warmer climates, and only then if I hear or feel the engine having issues.

As Mike mentions, not telling anyone what to do or how to operate their bike.

As for ethanol, ride often enough that the fuel never gets stale. Only time I would be concerned is during extended lay up periods that you see during the winter months in some of our more unfortunate provinces. Having mentioned this, never had issues with not using fuel stabilizer in my EFI Arctic Cat or other small engines when I lived in the colder climates.

Just thinking out loud and YMMV.

Cheers


Return to “Mike Nixon's Spot”

Who is online

Users browsing this forum: No registered users and 1 guest

cron