mikenixon wrote:Hi, gltriker. No, no bad effects, no fallout. The experience of mechanics everywhere confirms this. Not only is not harmful, it will gain you at least 10 psi and possibly 20 psi cylinder compression per cylinder. And the carbs, as I say, will work better, because they will get a stronger signal. They actually richen slightly.
As for accelerated valve wear, no. The 0.002" is invisible vertically. It's horizontally that makes the difference.
Hello, Mike! Please, be patient while I add some observations to your Topic. I am long-winded. Keep in mind this 1975 GL1000 engine has a nicely functioning, unmolested set of 1976 carburetors installed, and stock air filter housing and OEM Honda air filter element.
I'd already reported, several weeks ago, that I had reset the trike's intake and exhaust valves' clearance gap to 0.006". Since doing that seemingly little thing, several weeks ago, I have put, at least, an additional 900 miles on its odometer. Although those valve gap clearances were increased by 0.002", I haven't retested the individual cylinder compression results, yet. Eventually, I will.
Seems that small valve clearance gap increase, has unexpectedly presented measurable benefits that ties in with your statements I have highlighted above, in blue.
I am very
surprised, and pleased, that my trike's engine fuel mpg has increased, too! Honest! No exaggerations.....none!
Prior to my getting very interested/invested this Spring, after 25,000 trikified miles, with understanding how the change to the 'lower' final drive gear ratio, with a highly modified GM 3.73 to 1 rear axle assembly, and the exhaust system modification were affecting trike's engine performance, I had always utilized the number of miles that had elapsed on the trip odometer since the last fill-up, when it became necessary to flip the fuel tank petcock lever to its 'Reserve' position.
For the first 3 trikified years , (2013 - 2015) 117-119 miles was the typical trip odometer distance displayed at the time petcock lever flipover was necessary. Then, guestimating I could reasonably expect 4 gallons of fuel had been consumed, I accepted 29-30mpg would be the answer. During those first 3 years', 15,000 miles, my maximum speed was rarely faster than 60mph. true 60mph = 4,000rpm.
As I gradually became more confident in my trike's operational integrity, and my ability to operate it safely at higher sustained speeds, the average mpg at the higher engine speeds seemed, of course, to diminish a little.
In my 2016 quest to reduce exhaust system noise, after the first 15,000 miles elapsed, I replaced the H-D tapered mufflers (eBay) with H-D slash-cut units (eBay). When I discovered they were Catalyst mufflers, I envisioned only the worst. Not so. At that time, I reported, they woke the engine up! I always thought I was pushing my luck, though, if I attempted to ride more than 145 miles before filling the fuel tank again.
Coming back from the Canadian Rally last September, 2017, trike ran completely of fuel about 100 feet from my driveway. A few miles less than 150 miles was delivered on a full tank of fuel.
But, in addition to the conservative group riding speeds of 55mph in Canada, after crossing the Border into the US, I had run down the Interstate for 70 miles, at an average, sustained 75mph at approximately 5,000rpm.
Anyway, since removing the horrendously loud Rush mufflers I'd installed first thing this year, and re-installing the Catalyst mufflers that I'd voiced concerns about in the not-too-distant past, I've utilized a more precise method to calculate mpg now, as well.
But, I still adhere to the, let's see how many miles I ride until the fuel petcock lever has to be repositioned to 'Reserve'.
A week ago, it starved for fuel at 131 miles on the trip odometer.
This afternoon, 130 miles elapsed on the trip odometer.
26 miles later, I refilled the fuel tank this afternoon with 156 miles displayed on the trip odometer. The pump displayed 4.751 gallons of 87 octane gasoline was dispensed. Smart phone calculator results were 32.8 mpg.
Most times, since the valve clearance gap was increased, the flip to Reserve event averages around 123-125 miles on the trip odometer.
Still, it's better than the previous best standard of 117-119 miles.
Seems as though I can actually detect a difference in overall engine performance with some fresh fuel fill-ups, too.
THANK YOU VERY MUCH, Mr. MIKE NIXON!