Author Topic: Just joined from Minnesota  (Read 438 times)

Offline DavidMN

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Just joined from Minnesota
« on: October 20, 2020, 07:35:34 pm »
Just bought the Concours Oct.8. It's my first Concours and I really like it. It has a wide power band, smooth power flow, and great brakes. It has nice soft suspension and directional stability on curves. It already had some mods that I would have made myself: handlebar risers, rear lowering links, and a modified side stand.

I've been a self-employed motorcycle mechanic for 10 years now. I test-rode many different models and types of bikes. I owned a 2002 GSX-R600 that I took to many track days, so I've had some sport riding experience.

This Concours idled very roughly when I bought it, but seemed fine on throttle. Of course it runs perfectly after I rebuilt the carbs and changed the oil. I drained 7 quarts of oil/gas out of the crankcase. It is amazing how well it ran that way. I also put on a new rear tire and rear brake pads and took care of many other details. It had 46,000 miles.
2002 ZG1000

Offline Boomer

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Re: Just joined from Minnesota
« Reply #1 on: October 21, 2020, 01:26:18 am »
Welcome David  ;D

7 quarts of oil/gas? Holy crap!  :yikes:
I assume that you have also replaced the fuel petcock with a new one and checked all 4 pistons for symptoms of hydro lock?
George "Boomer" Garratt
Wickford, UK


Offline DavidMN

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Re: Just joined from Minnesota
« Reply #2 on: October 25, 2020, 12:43:50 pm »
You know, I've seen several extra quarts of diluted oil in quite a few bikes that I've fixed in the past few years. It's not that uncommon. I had the tank off and tested the petcock for about 2 days and it did not leak a drop. I think the previous owner must have left it on prime for a long time. One of the float needles leaked pretty bad, so that's what filled the crankcase. I've had many customers that didn't know what PRI was, many of them thought it was OFF. I've had to convince them it was quite the opposite.

I haven't noticed any symptoms of damage from hydrolock, so I don't think there is any. Before I bought it I noticed the engine had less mechanical noise than two other Concourses I tested. After I fixed the carburetors and synced the throttles and adjusted the idle mixtures, it idled dramatically better. Now the idle is very smooth and strong and it runs smoothly at 70-80 mph. It's a healthy engine.

But, what kind of a piston check are you talking about?
2002 ZG1000

Offline DavidMN

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Re: Just joined from Minnesota
« Reply #3 on: October 26, 2020, 06:12:06 pm »
From what you said and some other posts mentioning bent connecting rods, I decided to check mine. I pulled the spark plugs and positioned each piston at TDC and measured from the bottom of the plug holes down to the pistons after cleaning the surfaces. They checked 1.135", 1.130", 1.130", 1.132". I'm pretty sure there is no damage to pistons or rods.
2002 ZG1000

Offline Boomer

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Re: Just joined from Minnesota
« Reply #4 on: October 27, 2020, 04:07:20 am »
Cool, sounds like you got a good one.  ;D
They are prone to hydrolock if the petcock leaks whilst a float needle is held open by crud.
Some use petcock rebuild kits but my experience is that they fail sooner.
If you replace a leaking petcock with a new one from Kawasaki (~$90) then you can pretty much forget about it for 10 years.

George "Boomer" Garratt
Wickford, UK


Offline DavidMN

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Re: Just joined from Minnesota
« Reply #5 on: October 27, 2020, 07:21:58 am »
There are other petcock options too, like an aftermarket auto-shutoff type or an aftermarket manual-only type, but right now I'll keep using the one I have. I know it could fail, but I so can many other things.

I do a lot of carburetor repairs and I know my float valves all shut off positively because I always check them with air pressure when I do carbs. One needle on this Concours leaked because the viton tip had begun to separate from the metal. I've been seeing this a lot for the past few years. You can't see it unless you push the tip with your finger under strong magnification and bright light. The needles look like new, but the viton loses it's bond with the metal on one side and the tip shifts slightly off-center so it can't touch the seat all the way around and it leaks.

I know debris like rust particles can also cause a float valve to leak, as well as fuel varnish, corrosion, and wear.

Hey, is it true you can't post anywhere on COG without paying money?
2002 ZG1000

Offline Boomer

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Re: Just joined from Minnesota
« Reply #6 on: October 27, 2020, 11:51:10 am »
No, you can join COG for free as a Forum Only Subscriber, but you only get 6 months for free. After that ya gotta join the club and pay.
They just changed it last month, so after being an active contributor on the email list-server and forums since the mid 90's and a paid-up member of COG for about 10 years in the late 90s and 00s I decided I'd had enough of their politicking and quit the COG forum. This forum existed years before the COG forum anyways, in fact this used to BE the COG forum before the politicians got involved and caused a big split.

I replaced the float needles in my 1989 carbs about 5 years ago. They had no signs of separation of the coating but it was visibly worn.
They are cheap enough, unlike the diaphragms. Luckily the diaphragms seem to last really well.  ;)

I've never been keen on manual petcocks. If you forget to turn it off, and a carb is leaking,....  :yikes:
With the vacuum petcocks there is an automatic system that shuts off the fuel as soon as ya stop the engine.
Of course that is all moot now as new bikes are all fuel injected, so only the old carb bikes are affected.
Some on here have disabled the vacuum side of the petcock and fitted electric solenoid fuel shut off valves and I guess that would work too.
George "Boomer" Garratt
Wickford, UK


Offline just gone

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Re: Just joined from Minnesota
« Reply #7 on: October 27, 2020, 12:46:54 pm »
First off, WELCOME DAVID  :grouphug:

Disclaimer: I've never owned nor ridden a C10,...but, in addition to petcock maintenance and replacement
I thought there was an overflow tube install fix to the carbs that would prevent hydro-lock...no? Yes? Seems like
something that David would be able to do by himself without Steve's assistance.

Offline DavidMN

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Re: Just joined from Minnesota
« Reply #8 on: October 27, 2020, 04:26:57 pm »
I saw that idea, pretty cool and kind of funny, because I've seen posts elsewhere years ago that go the other way. They take old 1970s carbs and eliminate the brass overflow tubes because they sometimes split down the middle and cause a leak. I have seen it myself. I think it happens in storage from water condensation freezing. Yes, I could add brass tubes, I just think it's a lot of unnecessary work. I think I would fix my carbs due to other symptoms of leaky float valves that I would notice before it got bad enough to cause hydrolock.
2002 ZG1000