need my carb cleaned/ rebuilt

[RobertH121]

Hi my name is Rob and I'm new to the forum.I own a 1979 xs 1100 f and my # is 2h7-028798.I purchased this bike in July and have learned a lot about this bike because of this forum..my fixes have been pickup coils,updated fuse panel and i added accel 3 ohm coils and the bike came with pod filters and I believe,a,Mac 4 into 2 header with no mufflers but there are baffles in the straight pipes,I put. New plugs also which are gap at .34 because accel recommends a.35 gap the bike seems to be suffering a lean condition,exhaust popping,white plugs,and flat spot at half to full throttle,which makes me believe I need bigger jets and a full carb cleaning and synch ..I've down loaded the carb rebuild thread and feel confident about doing the carbs by myself,but I don't have the necessary tools to accomplish this..so here I am asking for advice to the many xs 11 wise men on this site to whom I could send my carbs to rebuild and rejet for me instead of bringing it to a dealership to get robbed and I feel as if I know this bike better than them lol..and a fair price to pay to have them done properly!!!!anyone come to mind that can do this for me..thankyou

[TopCatGr58]

Hey Rob,

It doesn't take any fancy special tools to work on the carbs. A good set of screwdrivers with a variety of sizes...the straight slots for the Pilot Jets especially. The other delicate part is the float mounting pins....they are interference fitted, and just need a delicate hand with set of wire dykes to be able grab the head of the pin to work it out. There are other ways, but trying to PUSH the pin out from the other end and post is where the breakage events occur...due to the interference snug fitting of the head end of the pin....along with possible corrosion due to steel/metal pin vs. the aluminum post. You can MAKE your own float height measuring/setting gauge out of firm plastic...even an old credit card and a mm ruler!

The other thing that is delicate is the PILOT SCREWS....remove them, and then use gentle 2 finger tension when putting them back on and screwing down to that "Gentle Seat" position before backing back out to the 1.5 or so turns out..so you don't WEDGE the fine tips into the carb body and then get them broken off in the bodies!

The other fancy tool that's needed is the vac. gauge for vac. synching and you will need that anyways....because all anybody will be able to do is BENCH synch the cleaned carbs...but they have to be vac. synched ON YOUR BIKE/engine to get them properly operationally synched! That can be done with just a single vac. gauge...a bit more of a PITA and time consuming....but can be done vs. spending the $$ for a proper 4 gauge set!

Any aftermarket type exhaust will cause some decel popping vs. OEM, but like you said...Pods, 4-2 pipes, and white plugs, you are probably running a bit lean and could stand to go up about 3 sizes in the mains and 1 size in the pilots...to 145 mains and 45 or 47.5 pilots...can't recall what the 79 has right off the top of my head! You can get Genuine Mikuni jets from a variety of places. You can simply POLISH the float needle seats and float needles. All of the metal parts can be soaked in carb cleaner, and then just use carb spray cleaner for the carb bodies. You do NOT need to separate the carbs from the rack. Follow the clean/rebuild thread.

T.C.

[SFerinTEXAS]

I would like to also note that the early carbs have a tendency to have the mixture screw tips break off in the carbs .When I got my E all 4 were broken .

[RobertH121]

Thank you for the advice.I will buy a screwdriver set and I'll pick up the synch from amazon..I was thinking about going with the 145 mains and 45 pilots.I saw some on amazon but I'm not sure what the part numbers are for the jets? are there specific jets for specific years for the mikuni bs 34 2 ,I think my 79 f has 137.5 for mains stock & 42.5 for pilots...thank you for your replys

[dbeardslee]

Thank you for the advice.I will buy a screwdriver set and I'll pick up the synch from amazon..I was thinking about going with the 145 mains and 45 pilots.I saw some on amazon but I'm not sure what the part numbers are for the jets? are there specific jets for specific years for the mikuni bs 34 2 ,I think my 79 f has 137.5 for mains stock & 42.5 for pilots...thank you for your replys

My 79F has pods and a 4/1, and I'm jetted 145 on the mains, and 45 on the pilots. According to the Jetting Recommendations I should have 147.5 mains, but on TC's recommendation I dropped back to 145's, and it runs better that way. If that holds true across the board, then with 4/2 exhaust you might do better with 142.5 mains. Not sure if the stock pilots would work better in that scenario, or if you should bump them to 45's. One way to find out...

And one other thing on pod filters. With a stock air box your carbs are supported both front and rear. A lot of folks remove the air box and just leave the carbs supported by the hangers - which is not what they were designed for. Your carbs will tend to bounce around a lot with that kind of setup, and that can't be good for your expensive carb hangers. I highly recommend bracing them in the rear to get rid of the bounce and to help preserve your hangers. JAT

And one other, other thing - what kind of pods do you have?

[mrhammer2u]

Here's where I bought my Mikuni jets....

http://www.jetsrus.com/a_jets_by_car..._BS_series.htm

[MarkD]

Welcome, Rob. Here is a pretty good vid on the general idea of rebuilding carbs .

https://www.youtube.com/watch?v=95nlrP-yn2I

I used stock sized (manual recommended size) jets- genuine mikuni from jet r us. After I removed the pilot screws, I took each separately, and then I reseated them LIGHTLY, WITHOUT the holding spring, as a method of counting the turns with no spring resistance . That way, I knew exactly how many turns I was going in when I would install them with the spring , so as not to break off the tip of the screw. The PO had left 2 broken tips in my carb bodies, so I was pretty paranoid about doing the same thing.

[motoman]

Hi my name is Rob and I'm new to the forum.I own a 1979 xs 1100 f and my # is 2h7-028798.I purchased this bike in July and have learned a lot about this bike because of this forum..my fixes have been pickup coils,updated fuse panel and i added accel 3 ohm coils and the bike came with pod filters and I believe,a,Mac 4 into 2 header with no mufflers but there are baffles in the straight pipes,I put. New plugs also which are gap at .34 because accel recommends a.35 gap the bike seems to be suffering a lean condition,exhaust popping,white plugs,and flat spot at half to full throttle,which makes me believe I need bigger jets and a full carb cleaning and synch ..I've down loaded the carb rebuild thread and feel confident about doing the carbs by myself,but I don't have the necessary tools to accomplish this..so here I am asking for advice to the many xs 11 wise men on this site to whom I could send my carbs to rebuild and rejet for me instead of bringing it to a dealership to get robbed and I feel as if I know this bike better than them lol..and a fair price to pay to have them done properly!!!!anyone come to mind that can do this for me..thankyou

As T.C. stated.........aint no rocket science involved either buddy........Trust us oldies here, you can handle putting back the way they come apart.

[TopCatGr58]

Mark has a pretty good idea. I remember reading a similar thing with the fork tube caps...using a magic marker to INDEX the cap so that one could see where to position it to start putting pressure while starting the threading to help reduce chance of cross threading.

SO...you could do a similar thing....no spring, just start the pilot screw into the housing...then while pulling up slowly unscrew it until it actually comes loose...STOP mark the screw where it will align with the same point/position of the carb body...ie. the front....or even mark on the carb body as well.

Then put the screw back in, and slowly screw in till it just stops...and notate how many turns it made by counting the turns..easier with the marks. Then you're ready with the spring in place, knowing how many turns it will take to reach the gentle seat position...and then you can back it out the 1.5 or so turns out for your starting point. JAT!

T.C.

[RobertH121]

Thank you so much for the advice and wisdom.I purchased the bs/30/96 pilots jets are these the correct pilots for my 79 f? & what rebuild kit do I purchase?I'm worried that I have to replace o-rings e.t.c and want to be prepared ...

[dbeardslee]

Thank you so much for the advice and wisdom.I purchased the bs/30/96 pilots jets are these the correct pilots for my 79 f? & what rebuild kit do I purchase?I'm worried that I have to replace o-rings e.t.c and want to be prepared ...

Those look like the right pilots, but what size did you get?

I got hunting around for genuine Mikuni jets last night and found that Niche Cycle Supply carries a nice selection.

As far as kit's - you're probably better off just buying the parts a la carte. I'd recommend pilot and main jets, needle and seat, and bowl gaskets. The rest of the stuff you can just clean well.

[RobertH121]

I went with 45 pilots and 145 mains for pod filters,accell coils and wires 3 ohm,and Mac 4-2 exhaust but with straight pipes with baffles..and will do on the gaskets,needle and seats..thank you again for replys

[RobertH121]

I bought pod filters on Amazon and they have a gap between the air jets so they don't restrict the carbs I think..there was no brand name on them but I paid 20 ish dollers for them and the quality I'm impressed with and they don't seat over the opening of the jet/ air holes...just need to pick up k & n oil for them..

[RobertH121]

Thank you all for your help and inspiration..ive read a lot of the threads on carb cleaning and tips but I'm a little confused with the float settings and how too' s I have calipers and then I see threads on setting floats with gas hoses ? Which do I go with the calipers or filling floats with gas or is it both? I'm confused about how to approach this? Do the carbs need to be filled prior to putting back on the bike?

[dbeardslee]

I bought pod filters on Amazon and they have a gap between the air jets so they don't restrict the carbs I think..there was no brand name on them but I paid 20 ish dollers for them and the quality I'm impressed with and they don't seat over the opening of the jet/ air holes...

Don't bet on it. The pods I had to take off my brother's G had a little gap too, but a lip will disrupt the airflow enough to still booger up the deal.