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Carb replacement options

Started by a.graham52, April 13, 2016, 08:52:42 PM

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a.graham52

So, now that I'm tearing into my father's bike, iv found the #4 carb has seized. Corrosion started from water entering the throttle shaft and corroding all around the butterfly. I let it soak for 2 days and today ended up bending the blade. What years will work on an 86 fj?

FJmonkey

84 to 87 are gravity feed and are bolt on, 89 to 90+ can be converted to gravity feed, Randy has the parts.
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

a.graham52

Quote from: FJmonkey on April 13, 2016, 09:05:57 PM
84 to 87 are gravity feed and are bolt on, 89 to 90+ can be converted to gravity feed, Randy has the parts.

Is it a big deal to convert? I can only seem to find 91+ carbs on ebay. What about 1100? Would those be ok?

Tor-King

Hi a.graham52.

1984-1985 are FJ1000's and their carbs will work as they are gravity fed.  To convert pump fed carbs, you need to replace the T between carbs 2 and 3 with one of these:
http://rpmracingca.com/proddetail.asp?prod=Carb%3ACarbFitting&cat=39

Dean

1993 Yamaha FJ1200
1988 Yamaha FJ1200
1986 Yamaha FJ1200
1984 Honda Nighthawk S 750
1972 Yamaha XS-2
1972 Honda CT70
1974 Honda CT70
1992 Yamaha DT50 MX
2012 Honda CBR250R
2008 Honda CBR125R

movenon

Quote from: Tor-King on April 13, 2016, 09:27:23 PM
Hi a.graham52.

1984-1985 are FJ1000's and their carbs will work as they are gravity fed.  To convert pump fed carbs, you need to replace the T between carbs 2 and 3 with one of these:
http://rpmracingca.com/proddetail.asp?prod=Carb%3ACarbFitting&cat=39

Dean



The needle and seat valves are different with a fuel pump (smaller opening). Here is a link that might help. RPM also has those.http://www.fjowners.com/index.php?topic=5150.msg93596#msg93596
George
Life isn't about having the best, but about making the best of what you have...

1990 FJ 1200

racerrad8

Quote from: a.graham52 on April 13, 2016, 09:09:56 PM
Quote from: FJmonkey on April 13, 2016, 09:05:57 PM
84 to 87 are gravity feed and are bolt on, 89 to 90+ can be converted to gravity feed, Randy has the parts.

Is it a big deal to convert? I can only seem to find 91+ carbs on ebay. What about 1100? Would those be ok?

You will need to break down the late model carbs to install the dual 10mm inlet tees between 1/2 & 3/4 carb banks. You can either cap the stock center tee or you can install the conversion fitting I manufacture: Carb Conversion Fitting

As already mentioned as well, you need to install the larger needle seats for the floats.
Googleypants, a search engine
Needle & Seat Assy (2.3) (Gravity) OEM Yamaha

Now, 1100's will bolt on but I have found they do not work well with the 1200 or larger bore engines. I could not make Pat's original flat bottom slide carbs run on the 1350 several years ago so a new set of converted 1200 carbs went on.

Randy - RPM
Randy - RPM

a.graham52

Quote from: racerrad8 on April 14, 2016, 10:59:35 AM
Quote from: a.graham52 on April 13, 2016, 09:09:56 PM
Quote from: FJmonkey on April 13, 2016, 09:05:57 PM
84 to 87 are gravity feed and are bolt on, 89 to 90+ can be converted to gravity feed, Randy has the parts.

Is it a big deal to convert? I can only seem to find 91+ carbs on ebay. What about 1100? Would those be ok?

You will need to break down the late model carbs to install the dual 10mm inlet tees between 1/2 & 3/4 carb banks. You can either cap the stock center tee or you can install the conversion fitting I manufacture: Carb Conversion Fitting

As already mentioned as well, you need to install the larger needle seats for the floats.
Googleypants, a search engine
Needle & Seat Assy (2.3) (Gravity) OEM Yamaha

Now, 1100's will bolt on but I have found they do not work well with the 1200 or larger bore engines. I could not make Pat's original flat bottom slide carbs run on the 1350 several years ago so a new set of converted 1200 carbs went on.

Randy - RPM

Randy, I just ordered rebuild kits from you. Any chance I could send them back and get credit if the owner of my money gives me the OK on new carbs?

racerrad8

Quote from: a.graham52 on April 14, 2016, 02:24:53 PM
Randy, I just ordered rebuild kits from you. Any chance I could send them back and get credit if the owner of my money gives me the OK on new carbs?

Sure thing.

Just let me know via email.

Randy - RPM
Randy - RPM