CB1100 Idle speed instability problem

[pdedse]

I'm into linguistics as a language teacher, so fun to hear both sand and salt used...but forgive me if I return to topic

Since my high idle issue just started, I think I want to chronicle exactly what's going for my own and others' reference, things I do or do not do, and results. I know we have the spreadsheet, but a bit more description here.

My bike: 2014 Standard, purchased Jan, '16. Currently near 9k miles, but 8k valve check not done, all other maintenance done as scheduled.

About three weeks ago, after an hour ride, fairly warm day, almost zero stops through country riding I stopped for gas. Idle spiked to 1500 and stayed that way 2.5 miles home. Started right away, same 1500 idle. An hour later, started and idle settled at 1000. Went on vacation till yesterday.

Today: (90+ temp) did the "the throttle twisting reset" (Key on, gauges cycle, then kill switch on, wait for under tank sounds to cease, three slow throttle twists from zero to full. Kill switch to off position, key to off position. Key on, gauges, kill switch, sounds done, start) as MM300 stated a while back (does this come from the owner's manual?).

Cold bike idled at 1400-1500 then dropped to 1200 after a minute or two. Within 1 block idle speed rose to 1500. Rode 2.5 miles to buy Seafoam and added 4oz. Did throttle reset again. Idle stayed at 1500. Did WOT for 2-4 seconds a number of times on local hiway in gears 2, 3 and 4. Couldn't safely get much above 6000rpm because of traffic. Idle speed dropped to 1000 and stayed that way for a number of stops during a 10 mile "spirited" ride.

Stopped bike, turned off engine with kill switch. Let sit for 1 minute, started bike and idle jumped back to 1500. Rode 4 miles and idle stayed at 1500. Shut off engine and restarted, idle dipped to 1200 then rose back to 1500 within a few seconds. Rode another 15 miles mostly hiway, again trying to ride WOT in different gears for 3-4 seconds each time. Idle would not come down from 1500.

Rode about 22 more miles of mainly hiway, did WOT when I could. 1500 up to 1700 idle when I came to a stop. Let bike sit for 30 minutes. Started and idle was immediately 1000. Rode 15 miles, no more testing of throttle and WOT. Each stop bike was at 1000 rpm. Shut off bike, let it sit for 1.5 hours. Started and idle maybe hit 1200 but then came down to 1000 right away. Stayed at 1000 at all stops for 5 miles home. Idled a minute at home at 1000 and it didn't budge.

Not holding my breath that the end result today is permanent, but I would be thrilled, of course, if it lasted a while.

No other "fixes" were attempted, only what was described here. I'll continue to report what happens over the next few days whether trouble returns or doesn't.

Comment: no one wants to, but I could live with this. The thing I don't like is that when I roll off throttle to check speed coming up to traffic or a stop sign/light, it's as if I continue to accelerate. The engine doesn't wind down and brakes have to be used more.

Hope it helps.

I found out about the reset from this forum, earlier in this thread. Not sure if it's in the manual. I just put the 'step by step' of what I did for future reference.

Update on my bike: It's been almost a month since I first did the reset, I've never repeated it after the 2nd time I did it and the bike has performed and idled perfectly, under every riding scenario, since.

That it is good to hear!

Today, Sunday: 90 degrees. Added 2-3 oz. more of seafoam. Started bike, idle for 2 minutes at 1250. Didn't come down any, but within a block of riding it settled at 1000rpm at first stop. Road 2 miles to gas station and idle stable at 1000. Filled tank and idle still stable. Road 5 miles city traffic, stable. Stop and let engine sit for 3 minutes. Start up and 1000. Road 4 miles with WOT in 2nd for 3 seconds hitting 7000rpm. Idle good. Turn off and start, idle stable. Road 2 miles, idle good.

Start up again, idle good. Rode 20 miles through forest, twisty roads, few stops, WOT multiple times in gears 2-4, idle good at stop. Let sit 30 minutes. Idle good at start. Rode 15 miles, normal. Opened gas cap, trying to imitate what initiated the problem 3 weeks ago. Started, idle still at 1000. Road 10 miles home, 5 through some city traffic. No problems.

Summary: once warm, the bike didn't bump one iota from expected 1000 (1050?). I say 1000 because the needle was dead set on the line. I added the seafoam again, did not do any throttle adjustment like yesterday, only rode WOT several times on country roads.

So...what does that mean? Whatever happened at latter part of the ride yesterday (the last 25 miles) stuck and the bike behaved flawlessly today.

I'm encouraged of course to read that MM300 has one month without difficulties and that my day 2 was all good.

I will say this: I've really enjoyed riding the WOT moments! If I keep doing this, I'll need to up the life insurance a 100k.

Note: this is only the second day of riding after the bike sitting 3 weeks.