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Discussion Starter #1
I want to rejet my o4 bonnie tomorrow and am wondering if I remove everything
except the throttle control linkage (which I understand is tricky to put back
correctly)

I plan to remove the tank, pull the heater connectors, and unhook the TPS, then
the intake rubbers and pull off my air filters (the airbox is already removed)

Will this give me enough freedom to slide the carbs out and turn them slightly
for easy access to the bowls?

Thanks!
 

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I want to rejet my o4 bonnie tomorrow and am wondering if I remove everything
except the throttle control linkage (which I understand is tricky to put back
correctly)

I plan to remove the tank, pull the heater connectors, and unhook the TPS, then
the intake rubbers and pull off my air filters (the airbox is already removed)

Will this give me enough freedom to slide the carbs out and turn them slightly
for easy access to the bowls?

Thanks!
Yes, that will work. The carb boots can be a bear to deal with.

Do you have a set of the stainless hex headed carb screws? If you do, the next time you want to change the main jets you can just drop the bowls. Actually, you can do it with the stock screws but they're soft and easy to mess the heads up...

The pilot jets are tougher to deal with as they're recessed a good bit.

All that said, I had my dealers mechanic do a total rejet while I had the Bonnie in for a valve job. He did everything with the carbs on the bike and with the stock screws (I hadn't received the SS hex screws yet)... It pays to have all the right tools!
 

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IMHO, removing the carbs is a BIG waste of time for a rejet. The tank doesn't even have to be removed or raised some if you are not doing anything with the needles.

Simply get a good mirror, lay a towel on the motor under the carbs (a white towel is best for finding the little things one sometimes drops). Get a good 1/4 " ratchet with an adapter to accept a new #2 Phillips bit or get the proper JIS bit...push up on the ratchet with one hand until you see the carbs move upward a little bit, then turn the ratchet with the other hand.

Caution: The main jets screw into the "needle jet holder". Use a wrench to hold the needle jet holder to keep it from unscrewing. If one removes the needle jet holder, the needle jet can fall out and it is not readily apparent which way it goes back (the needle jet is a small brass ring type thing).

Caution #2: Be sure your screw-driver is the proper size to fit into the cavity where the pilot jet is located, if you plan to change the pilot jets.

SS Allen Head Screw kits: The ones I have seen come with lock washers for the screws. DO NOT USE lock washers on the two screws for the left carb that hold the idle adjust bracket to the carb! The washer will make these two screws too short. If you are concerned about not having lock washers for these two screws, purchase two longer screws for this application.

Take your time and you will be fine...the next time you will be able to do this job in 1/4 the time.:D

Most screws and jets are MUCH tighter than they need to be, so I would recommend you not try to tighten (over-tighten) the screws and jets like they came from the factory.
 

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+1 on what redbird said - there really is no need to take the carbs off. Follow Larry's directions, you will be in good shape.

The only thing I will add, which I just discovered a few minutes ago answering someone elses thread, is that if you DO take the jet holder out, the collar that it holds in place will only actually go in one way. If you put it in the wrong way round, it turns out that you won't be able to even engage the threads on the jet holder. Even so - no need to take the jet holder out. Hold onto it with an 8mm wrench while you undo the main jet.

Here's a link to the other thread I mentioned, 'cos it has pictures in it.

http://www.triumphrat.net/twins-technical-talk/98514-little-help.html
 

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I helped killian101 rejet his carbs a week ago. Had we not removed the carbs, we'd have never gotten one of the screws out. If the carbs have never been apart before, I would highly recommend removing them.
 

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Interesting - I didn't have any trouble getting the screws out of mine.

Well - bearing in mind what pokeyjoe says, I suggest you start by leaving them in place, but be prepared to remove them the instant you ancounter any difficulties. Don't be tempted to soldier forth - you might get into more and more difficulty.

Take this approach, and if it works out and you can leave them in place great, and if not, nothing lost.

The stock screws are certainly very soft- so at the merest suggestion of them rounding, do what pokeyjoe says and remove the carbs.

I did mine using a mini ratchet set - that way I was able to apply good upward force on the driver into the screw head, so that it didn't "cam out".
 

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If this is your first time rejetting your Bonnie you can save yourself a whole lot of aggravation by removing the carbs. Really. The screws can be a bugger to remove the first time. Count on at least 1 & maybe 2 to resist your removal efforts. No worries, the a small vice grip will defeat them.

Another reason to remove the carbs is to check the float heights. That is much easier to do when the carbs are out.

I suggest that you replace the phillips head screws with stainless steel socket or mushroom head allen screws. They are a sign of touch of class for someone who knows what to look for.

There is no need to remove the throttle cables. After removing the hoses & disconnecting the TPS, remove the intake adapter boot clamps, work the carbs free, & then work the carbs boots out. You can then work the carbs out the left side, flip them over, & place them on a short section of wood (like a short 2x4) on the top of the frame & you have plenty of room to work. Steady them, or they will fall.

A thin towel on the engine will help keep things from getting scratched.

Also do yourself a favor & drain the float bowls before you pull the carbs. A short section of tubing on the left side bowl will help drain that bowl, given the limited clearance. I drain the right side first & that gets the fuel tank hose too. That way there's less to deal with on the limited clearance side if the tubing slips off.

A shot of silicon spray on the intake adapter boots will help you get things back together. I put the boots on the carb side first & then grasp both sides from over the top & get the carbs into the intake side. The spray makes it a snap.

Speaking of the boots, remember the little raised nub goes on top, & it faces the engine side. It is very easy to get that wrong.

Yes you can change the mains with the carbs in place, & if you approach that as an advanced technique then in the long run you should be a much happier camper.

Good luck & happy wrenching.
 

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screw driver

When I did my rejet, I did replace the carb screws, left the carbs attached. Be sure to use the exact size screw driver tip on the carb screws and a proper fitting straight slot screw driver. Found one that was close and filed the tip to fit snug in the new jet before I removed the old one.
 

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Discussion Starter #10
Thanks for all the advice. This is the first time I have tried to rejet, so I
will probably take the slow and long way round and pull the carbs right
out. I do not have the SS Allen screw kit, so I might just get that and some
better hose clamps and do that at another time.

Thanks again, I will let you know how it goes!
 

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Discussion Starter #11
That didn't go so well...

The left side went fine, and I replaced the main and pilot jets and then
buttoned up the float bowl and started on the right side. I knew the tension
the soft phillips screws were tightened to, and even though I was careful, I
still manged to round out slighty 2 of the screws such that my screwdriver is
now too sloppy to do an good.

I then took my screw driver and ground a little off the tip so that I could
seat it a little deeper, but this didn't work either.

I will get a set of good needle nose pliers and hopefully they will be able to
grip the head of the screw and turn them out that way. The only other thing I
an think of doing is using a dremel to turn the phillips into slotted, and hope
they come out with the appropriate flat screwdriver.

What I want to avoid is having to drill the head. Any tips would be welcome at
this point!

I will hunt around for replacement screws at the hardware store tomorrow also.
 

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You're on the right track. A pair of vice grip pliers might be the trick to get the old ones out. Dremelling a slot can work, but it's easy to slip and damge the carb body. Try the plier / vice grip plier approach first. Then you can get some nice allen head screws in there, and you'll be fine from then on!
 

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Contrary to B02S4, I saved myself a lot of aggravation by not removing the carbs.

This past year was the first time I re-jetted, had no problem. It's awkward, but not nearly as much trouble as removing and re-installing the carbs is likely to be.

I had already replaced the screws, which I also did in-place, and fortunately I had no trouble removing them after I'd had the bike for two years. I was well-prepared with JIS stubby and full-length screwdrivers, and a mini-ratchet with a Phillips bit with some bite to it (small serrations on the tip, I think that they're sold to use with hardened screws).

I removed the tank both times. It's easier to work on the carbs in-place with the tank out of the way, and removing the tank is far easier than removing the carburetors.
 

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I think it is fair to say that if you are running the airbox then that does complicate things. I have pods & the BC ABEK, so pulling the carbs is a snap.

That said, even if the bike has the wheeze-box it's a good idea to pull it apart at least once, remove the carbs, & see how things work.

Funny how we can approach the same issue & have such different perspectives :D
 

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My guiding principle is that I'd rather disassemble less, if feasible. I used an inspection mirror, and I had the photo in Jenks' guide by my side to identify the internal parts.

Granted, it's an easier job to remove the carbs if the airbox is out of the way. Mine isn't. :)
 

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I like small vice grips for that kind of a job, because you can use the lever action of the vice grip to really dig into that screw-o-softness and grab hold. Once you've cracked the first turn they come out easily, and then you can replace them with a nice hex head stainless steel screw-o-wonder.

The stuff everyone else said works too.
 

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Discussion Starter #18
Now that the job has been done, I am glad that I displaced the carbs this
time, just because I got a good look at inside the bowls, where all the hoses
go and so on, with the airbox removed it wasn't that hard, but next time I know
I will not need to go through all that.

As for those peskey screws, well I was unable to find hex head replacements,
but I can order them, as well as mixture thumb screws and put them in over the
winter. For now I bought philips screws for $2.50 but they have a much larger
and deeper head and are easy to get out.

A few weeks ago I did the airbox removal, it took most of the afternoon but it
went well and decided to defer the rejetting until the other day. I did ride
around the block but the bike was now so lean with the wrong jets it was almost
unridable.

Last night I went for a ride in lovely 2C weather with the new 150 mains and 42
pilots. Wow! I knew there would be some performance gains from an airbox
removal and rejet, but I didn't expect this! The bike pulls SO HARD now, it's
incredible, I love it. I also didn't expect the noise to change, the bike seems
to growl even louder now :)

Anyway, thanks for all the help! Now I will focus on a major brake upgrade for
this winter...do these mods ever stop??
 

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They never stop.....unless you really want to. Each to their own on that one.

Newbonneville sell a handy dandy screw kit for the carbs, with all the screws and washers already selected for you. Makes it an easy job, instead of sourcing them all yourself. Just an FYI.
 
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