Some Carb Detail Questions

[Anonymous]

I guess I officially joined the GS brotherhood tonight; I pulled the carbs on my 1100E for the first time. Did you guys hear the swearing? It has been covered before, but it is definitely the most ignorant thing I have done relating to a vehicle. Without all the warnings and horror stories I never would have had the nerve to be that abusive to a carb rack....Anyway, I have pulled the diaphragm caps and float bowls to see what I had and a few questions have now come up. Just to refresh the collective memory, my 1100 has a Kerker 4-1 canister system, a modified airbox with the back half of the box removed and a single large K&N filter in place of the stock paper element. The work was done by the shop the PO purchased the bike from and they tuned it and jetted on the dyno. Before my oddessy of maintenance began last year it started and ran well, with the jetting pretty well sorted. So, onto my questions:

1) The needles are adjustable (yay!), but do not look like the Dynojet kit needles I have seen previously (which have all had a very pronounced taper). These have almost no taper at all, looking very much like a straight rod. Are these stock or what? This is a Canadian model bike, did they come with adjustable needles stock in 82?

2) The cam chain tensioner is weeping oil and the carbs (especially #2 and 3) are really dirty with a partly baked on layer of oil and gunk on the outside (inside was very clean). Will carb cleaner take this off or should I use some brake cleaner to clean the bodies up before using the carb cleaner to clean out the float bowls and jets? Stupid question perhaps, but I have never had a set of carbs get this dirty on a bike I rode. The PO didn't seem to hold much stock in washing the poor thing.

3) The float bowls and jets were very clean, with only trace amounts of sediment in the bowls. I plan to just spray everything down with carb cleaner before reassembly. Since it ran and idled very well last summer, I see no reason to strip everything and dip them yet. Any reason to not just spray and then button them up?

4) Tonight's wrestling match has convinced me that pods are going on before I put the carbs back in (I was on the fence before tonight), so I am going to have to rejet somewhat. Since it is already jetted for the modified intake set up, I figure that I can start with one size up mains (currently it has 130's in with the needle on the #3 of 5 positions), which will be 132.5's. This can't be far off what it will need and should be a decent starting point. Any opinions on that?

5) I have found the pilot jet on the exploded view in my manual, but it is somewhat vague as to where it actually is in the body. From the diagrams, it appears to be directly to the engine side of the main jet. There was a boss there with a rubber or plastic plug over it on the carbs. Is this the pilot jet? How do I remove it to check the size?

6) The mixture screw is nicely placed on top of the carbs towards the engine side of things (for a change, my ZX-9 had them buried). Does the idle mixture get richer or leaner as the screw is turned in? I haven't found the number of turns for that screw in my manual (yet), does anybody know what the stock setting is for an '82 Canadian model?

Lots of questions, I know.

Any help/experience/opinions welcome.


Thanks,
Mark

 

[Hoomgar]

The initiation is complete, welcome aboard

I'll have to let the pro's answer your questions though.

I am just on the welcoming committee. :lol:

 

[Jethro]

Be prepared, I'm going through a nighmare trying to get my 83 jetted right with pods. I have since spent about $130 on jets! And it's still not right. I am now at 145 mains, highest spot on the needle, and am lean as can be. I just ordered every jet between 145 and 160- I better get it right now!

Anyway, the mixture screw should lean as you turn it clockwise (in). It gets richer as you go out. At least I hope I have that right. I've about had it with this jetting bull$hit.

Anyone selling a stock airbox and exhaust?

 

[Anonymous]

Anyone selling a stock airbox and exhaust?

Hah! I may have the front half and a nice K&N filter for sale shortly... Can't help on the stock exhaust, though.

Thanks for the info on the mixture screw. That's what it looks like in the diagrams, but I thought I better check before making an idiot mistake or two...


Mark

 

[Joe Nardy]

Re: Some Carb Detail Questions

Mark,

I'll offer up what I can to help here..................

1) The needles are adjustable (yay!), but do not look like the Dynojet kit needles I have seen previously (which have all had a very pronounced taper). These have almost no taper at all, looking very much like a straight rod. Are these stock or what? This is a Canadian model bike, did they come with adjustable needles stock in 82? Sorry, but I can't help with this.

2) The cam chain tensioner is weeping oil and the carbs (especially #2 and 3) are really dirty with a partly baked on layer of oil and gunk on the outside (inside was very clean). Will carb cleaner take this off or should I use some brake cleaner to clean the bodies up before using the carb cleaner to clean out the float bowls and jets? Stupid question perhaps, but I have never had a set of carbs get this dirty on a bike I rode. The PO didn't seem to hold much stock in washing the poor thing. Carb cleaner should get the gunk off. You may want to use a brush to help scrub off the tough stuff.

3) The float bowls and jets were very clean, with only trace amounts of sediment in the bowls. I plan to just spray everything down with carb cleaner before reassembly. Since it ran and idled very well last summer, I see no reason to strip everything and dip them yet. Any reason to not just spray and then button them up? I have never dipped my carbs since they are painted and I believe the dip chemicals will remove the paint. I use carb cleaner and compressed air to clean out all jets and orifices on the carb bodies.

4) Tonight's wrestling match has convinced me that pods are going on before I put the carbs back in (I was on the fence before tonight), so I am going to have to rejet somewhat. Since it is already jetted for the modified intake set up, I figure that I can start with one size up mains (currently it has 130's in with the needle on the #3 of 5 positions), which will be 132.5's. This can't be far off what it will need and should be a decent starting point. Any opinions on that? SHHHHHH! Don't tell Earl you're going to use PODS! My guess is that you will need to go higher on the mains. Your current setup is somewhere between stage 1 and stage 3 for the Dynojet kit. There is a significant difference in the main jet sizes between stage 1 and stage 3 in the Dynojet kit. I don't think the 132.5's will be extremely lean but I would be careful to do full throttle plug checks to be sure.

5) I have found the pilot jet on the exploded view in my manual, but it is somewhat vague as to where it actually is in the body. From the diagrams, it appears to be directly to the engine side of the main jet. There was a boss there with a rubber or plastic plug over it on the carbs. Is this the pilot jet? How do I remove it to check the size? Yes, the pilot jets are located under these plugs. They should have a flat blade screwdriver slot cut into the tops.

6) The mixture screw is nicely placed on top of the carbs towards the engine side of things (for a change, my ZX-9 had them buried). Does the idle mixture get richer or leaner as the screw is turned in? I haven't found the number of turns for that screw in my manual (yet), does anybody know what the stock setting is for an '82 Canadian model? Sorry, can't help here too much either. My '83 seems do be pretty indifferent to mixture screw settings. I ended up with mine 2-3 turns out. I believe turning the screw out richens the mixture. Somebody else can confirm or refute that.

Lots of questions, I know.

Any help/experience/opinions welcome.


Thanks,
Mark

I hope this helps. Good luck and keep asking the questions. I still owe you some answers for all your help with the forks.

Joe

 

[pano]

Mark I have the same bike with this set-up. Fortunately I am not having the crazy problem that Jethro is having. I lost hair getting it right though so I know what Jethro feels like.

K&N pod filters
Dynojet kit with the dj138 mains
Needles on the fifth notch from the top
Slides drilled per Dynojet
All other jets etc are stock sizes.
V&H supersport canaster

I started out with the DJ138 main and needles on the middle position (3rd from the top) as Dynojet instructions. I had sputtering off idle so I raised the needle by setting it to the 4th notch from the top. I then had sputting off idle after it warmed up and a flat spot at 3-4k rpm. I raised the needle to the 5th notch from the top and I have no sputtering, no flat spots, and the plugs do not look lean or too rich.

My idle screw are at 3-4 turn out for 3 carbs and 4-5 turns out for one

I do need full choke on start and then reduce it slowly while it warms up which takes about 5 minutes. I bought larger pilot jets to see if this solves the problem but have not tried them yet.

 

[Anonymous]

My guess is that you will need to go higher on the mains. Your current setup is somewhere between stage 1 and stage 3 for the Dynojet kit. There is a significant difference in the main jet sizes between stage 1 and stage 3 in the Dynojet kit. I don't think the 132.5's will be extremely lean but I would be careful to do full throttle plug checks to be sure.

I have been thinking about that and I will be going to 135's as a starting point instead. I am also going to step up one size on the pilot jets to help out the bottom end. I don't mind if it starts out rich and I need to lean it out, but too lean is to be avoided. I plan to do the initial tuning by feel (the "old fashioned" way ) and then fine tune it with an O2 sensor when I get it reasonably rideable.

I hope this helps. Good luck and keep asking the questions. I still owe you some answers for all your help with the forks.

Helps much. I am sure I will have evened off the question/answer ratio before this is done...

I do need full choke on start and then reduce it slowly while it warms up which takes about 5 minutes. I bought larger pilot jets to see if this solves the problem but have not tried them yet.

I had a similar problem with a stage 3 kit on my 86 GSXR. Stepping up 2 sizes on the pilot jet completely cleared it up and made the bottom end run much better.


Mark

 

[Jethro]

By the way Pano, I don't know how much you have been following my jetting saga, but it seems the #50 Mikuni pilot jets have really helped my starting. Of course, the float bowl cases had the starter jet fuel ports clogged on two of them, that might have something to do with it, but the pilots seem to have helped too. Anyway, at least that's some progress.

Mark, mixture screws in (clcokwise) will lean out the mixture. Mixture screws out will richen.

 

[pano]

By the way Pano, I don't know how much you have been following my jetting saga, but it seems the #50 Mikuni pilot jets have really helped my starting. Of course, the float bowl cases had the starter jet fuel ports clogged on two of them, that might have something to do with it, but the pilots seem to have helped too. Anyway, at least that's some progress.

Changing the pilots is #6 on my revised to do list.

 

[KEITH KRAUSE]

Jethro, just another thought. Do your carbs have any spacer(s) that would be re-installed with the new DJ jet needle? If so, any chance you or a previous owner forgot to install or installed any spacer(s) in the wrong order?

 

[Anonymous]

Boys don't want to rock the boat, but stick with your stock airbox, side wind, change of weather and rain will drive you crazy trying to keep your bike running correctly. Try 115-125 mains depending on your season temperatures with stock air box(removing air box lid can lean out for summer temps), 47.5 primaries(which also has an influence through the whole range), needle up(clip dropped), for stock needles(fat ones). If pods are a must try 170 mains with the same needles and primaries, that's what worked for me on open stock carbs on my old dragbike. If you can find them early Yamaha XS1100 needles and 140 mains work great. Just my three cents.