First Generation Ascots > The Thumper Years: Stock To Lightly Modified

Carburetor rejetting question

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frappy:
Thanks.  Nope, I used a vice grip on the shaft of a "shorty" flat blade screwdriver.

frappy:
Got the jets installed in my FT500 last night and (thanks to J's recommendation) didn't even need to remove the carb.  I also decided not to replace the float bowl gasket and thankfully it doesn't leak after reassembly and testing. Maybe I should've ridden the bike more than once before I changed to the recommended 2x oversize jets, but I'm not looking back.  The bike seems to start, come off choke, idle, and just plain run better throughout the rev-range.

To attack the job, I removed my side covers, seat and tank.  I loosed the clamps on the rubber intake and air box clamps to allow me to twist the carb as needed to get out float bowl screws, remove float bowl, and remove/replace jets.  I also removed the 10mm head bolt on the breather (Honda's fiche calls it a "storage tank") to permit me to move it around when I needed to drop the float bowl (see pic).  Before dropping the float bowl, I made note of the position of the enrichment set-screw lever on bottom of carb (in front of bowl).  I employed a couple of make-shift tools to remove (and later reinstall) the float bowl screws and two jets. I used a screwdriver bit and either a 1/4" socket/ratchet or box-end wrench to remove the bowl screws (see pic).  The Main Jet came out easily with a 7mm (or 8mm) box-end wrench, and for the Pilot Jet I used a shorty screwdriver clamped very securely in a small Vice-Grip pliers (see pic). Once the old jets were out and new ones installed, I reattached everthing in reverse order then moved the carb back to horizontal and aligned notch on boot to corresponding tab on side of carb (see pic). 

Here's the pics of the tools I used to replace my Main and Pilot jets, the breather I loosened and the carb alignment notch. Hint: you will need to apply significant upward pressure on the driver bit and also the small shorty screwdriver, in order to avoid stripping the float bowl screws and pilot jet. I needed a small mirror to see and locate the slot position of the Pilot Jet, I did also need a flexible magnet to recover a float bowl screw when I mistakenly dropped it on the engine.

J6G1Z:
Good job! Thanks for the write-up & pics. This will help other folks that come along later.

One of those float bowl screws is a bit difficult to get to. To remove the slow speed jet, I used a parallel ground gunsmith screwdriver that fit the slot perfectly. I first tried it with a regular screwdriver & almost stripped out the notch.

Another great & simple modification that really helps after the jetting change, is to swap the countershaft sprocket to one or two teeth larger. The OEM stock countershaft sprocket is a 15 tooth. I swapped to a 16 tooth & really liked how it allowed the engine to lope along at highway speeds. Some guys go with a 17 tooth, but on some bikes there is a washer that needs to be clearanced for the 17 to fit.

Modify the bike to build more power, than gear it up to go faster.

J.

WTF304:
Hello guys, I'm new to the forum but not new to this bike. I forget who posted the dyno pull but reading it gave me a little insight on re jetting mine. Have the manual infront of me ( after digging it from my shelf)  and was curious to know something. Now assuming the slow jet ( pilot), is different size depending on where the bike was sold ( again, assuming that basing an opinion on altitude) because the book doesn't really say it's factory/generic size. And i think but could be wrong but i recal somewhere it was listed as a #35, i had one that was setup to ice race and the slow jet was a #52. The main was still a 140 like the book said and i haven't pulled the carb from my stock FT to know if it has been opened up. Is the factory installed jet a #35 ? Or was that just some bs i read ? .... i went to my somewhat local shop today and picked up a #52 slow jet and a #160 main in hopes to fatten up the fuel mix a bit, don't want to run lean. My ice race bike was put together by the PO and that was years ago when i bought it off his hands.

WTF304:
Nvm guys i did manage to find the size spec for the slow jet in the book, it's been awhile ( laughing at myself ) for some reason i didn't think it was stock. ;D

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