Carb maintenance update ...

Hey all,

Well the '95 VFR750 is running !!!! YEAH!
Thanks to all for the input, really appreciate it !

Since I really did not want to tear down the carbs, I started with John
Johnson's advice: found good carb cleaner, drained the fuel and filled
with cleaner. Let soak, drain, let it dry.
Poured fresh gas in, and Woohoo ! There it goes. A few stumbles first,
but now throttle response is good throughout the rev range.

Thanks again !

Olivier
'99K1200RS Yellow
'98VFR800 Yellow -> I DID find bits in my oil pan: 2 collars and 2 metal
bits broken off from something. Ok, now off with the engine to get to
that tranny ...





>
> ------------------------------
>
> Message: 6
> Date: Thu, 3 Jan 2008 22:34:27 -0500
> From: John Johnson
> Subject: Re: Carb maintenance help
> To: Olivier Gerouville
> Cc: vfr@xxxxxx
> Message-ID:
> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
>
>
> On Thursday 3Jan, 2008, at 4:02 PM, Olivier Gerouville wrote:
>
>
>> Hello and happy new year everyone !
>>
>> Well, I need to verify that the carbs on a '95 VFR 750 are working
>> correctly. I guess they need some maintenance. So, I've never been
>> close
>> to a carburetor before (thank you FI !). Haven't seen much helpful
>> info
>> in the archive, and I'm interested in any advice or useful "how-to"
>> reference.
>> In the shop manual, it says "Vacuum chamber and float chamber can be
>> serviced with the carburetors assembled", so do I need to take the 4
>> carbs assembly off of the bike, or can they stay on to do this (I have
>> the tank and airbox off). Do I simply spray carb cleaner in there ??
>> I don't understand how to get to the jets (main jet, needle jet, slow
>> jet). Are they "in" the carburetor ? Can I take them out ? Do they
>> need
>> cleaning ? How ?
>>
>>
>
> Woah, woah, woah. Don't be taking those carbs apart just yet (though
> you're probably going to have to eventually).
>
>
>> I would also appreciate any pointers on a more general issue (for
>> those
>> of you with snow outside and the bike stuck in the garage). This
>> '95 VFR
>> came to me in march '07 in bad shape (lots of fried electrical bits,
>> toasted brake pads and discs, ...). Back in october, I finally got it
>> all fixed, took me a while to get it to start, but it finally did,
>> so I
>> let it run for a good 30 minutes, to get it hot. Here we are, 3 months
>> later, I put everything back on (front-end, brake everything, new
>> filters, and bodywork). Crank it up .... NO GO! The best I can get
>> is it
>> will start and run for about 30secs. then stalls. So, after my
>> frustration has come down, I take off the tupperware: I have spark to
>> all 4 plugs, and they are slightly wet. I switched to new fuel, and it
>> gets to the last "T" before the carbs, but still no go, so I'm
>> guessing
>> the problem is inside the carbs. Another thing I noticed is that as
>> soon
>> as I open the throttle the bike obviously stops trying, cranks slower,
>> and dies.
>> Any pointers here ??
>>
>>
>
> First off, it does indeed sound like your carbs are plugged up, and
> if they've been sitting with gas in them since March, it's no wonder.
> I'd start with an in-carb cleaner. Here in the US, the brands to look
> for are Berryman's B-12 chemtool, and SeaFoam carburetor cleaner. I
> think that Yamaha sells the SeaFoam product re-badged. I don't know
> what's available over there, but you're basically looking for a
> witches brew of xylene, toluene, and other carcinogens.
>
> The usual method is to drain the gas out of the carbs, and pour the
> cleaner in until they're full (obviously, you'll need to reinstall
> the drain plugs, and to make sure any overflow doesn't get on you or
> on painted surfaces. IIRC, the instructions tell you to leave the
> stuff in there for 30 minutes then drain out. After that, try fresh
> gas and see what you get. If it works well enough to hold an idle,
> you can then put 5-10cc of the stuff into a full tank of gas and ride
> it around, paying extra attention to low throttle settings (because
> those circuits tend to clog up worse).
>
> If that doesn't do the job, you're looking at removing and tearing
> down each carburetor, and preferably putting all metal parts into a
> container of carburetor cleaner (it eats plastic and rubber!). I've
> _read_ that hot ethylene glycol coolant will do the job overnight
> without the eating rubber part, but I've never tried that myself.
> Basically you clean all parts, make sure all removable jets are
> spotless, and spray a bunch of carb cleaner under pressure through
> the non-removable ones. Make sure there's no deposits on the needle
> or its seat (use a magnifying glass!) and re-assemble.
>
> Oh yeah. There was a guy who hung out on Usenet's
> rec.motorcycles.tech forum who had fine carburetor cleaning
> instructions. Use your favorite usenet archive (e.g. Google-groups)
> to search for 'krusty kritter' or 'kaybearjr' and 'carb cleaning' and
> you'll come up with the instructions.
>
> HTH!
> Johnj
>
>
_______________________________________________
vfr mailing list
vfr@xxxxxx
For subscription and delivery options:
https://lists.cs.wisc.edu/mailman/listinfo/vfr