20 year car mechanic screwed up the Holeshot install

[Johnny from Chicago]

I followed the instructions to the letter and it idled OK but had a lean spot at 4k in driveway. So bad it would stall. After revving it for a few mins it picked up a miss at idle and stalled. Runs for crap now and I have no idea what I did wrong. I did not lose the tiny O rings. and the shims are all the same(went with 4 to start) went with 110 jets and 17.5 pilots with screws 3.75 out like he says to start. Now I can't ride in tomorrow, the day of the California Carmaggeddon!

[rider123]

First thing I would try is tape over the 1.5" hole(You did cut the hole in the top of the airbox right?) or at least half of it to see if that helps. If the bike runs better then you are lean. I have a hole shot kit at 4 turns out and 5 shims(110 mains) and had to reduce the hole to 1 1/4" and it's still a bit lean up top, will be installing the 112.5's next week. I would also put 5 shims on there for sure. You are closer than I am to sea level so you will need to richen it up a bit. Try 4 turns out and 5 shims and see if that helps.

What do the plugs look like? You should have one full turn of light color on the base ring of the plug. Thats where the ground strap is welded to the plug. Also look at the porcelin. Right down inside of the plug where the porcelin meets the body you should have 2-3 mm up the porcelin of colour, if it is bone white you are lean. If the colour is black and goes up farther than a few mm's you are too rich. I'm guessing you are too lean.

Also make sure the float height is set to 13mm. This is EXTREMELY important! I had my jet kit installed by a shop(big mistake)and had all sorts of problems. After taking off the carbs to look myself the floats were all over hell's half acre. One was 11.5mm seeping fuel and another was 15mm starving that cylinder of fuel. After setting them to 13mm all was good.

Just because someone is an "expert" doesn't mean they will do a good job. My guess is he popped the jets in there and hoped for the best. To be sure he used the right jets, I would take off number 4 cylinders float bowl which can be done without pulling the carbs and either unscrew the jets or use a hand mirror to read what's been installed.

[Johnny from Chicago]

I guess I wasnt clear. I'm the 20 year car mechanic. I've rebuilt so many carbs over the years I thought this would be no different. The bike was running with the stock jets and this pipe before I took it apart and I know that was too lean. So I dont think lean would cause the increased problem after jumping up 10 jet sizes. It dropped a cylinder at idle now like it's rich.

[txbanditrydr]

Sounds like you did the kit install properly - although I think baseline is 5 shims.

Before you tear things fully apart to check float height (very good idea) I'd double check all hose routings and make sure you don't have a vacuum leak somewhere.  Double check the nipple caps on carbs 1 thru 3 and also check the fuel hose routing.

I'm guessing your working on a Gen 2 Bandit 1200 - if not you might post up your bike specs.  Good luck and let us know what you find.

[Johnny from Chicago]

Its a 2005 sz. I am wondering now about the 25mm that you're supposed to trim off the springs. Was he talking about 25mm of a coil like when you lower suspension by cutting off 1/2 of a coil turn, or 25mm of total length. (I did total length). Also, the 3rd carb has a nipple on the float bowl and I cant find anything that goes to it. I think it was connected to something when I took it off but cant remember for sure. I think this thing is too rich and fouled a plug. I need to pull them this weekend. I got disgusted with it last night and closed the door and poured a drink. I went with 4 shims to keep it a little more economical at cruise. I didnt want to take it apart again if it was too rich.(not sure how much diff each shim makes) Thanks for the quick responses. I'll try some stuff then report back. If no luck, I'll be calling Dale on Monday.

[rider123]

No you trim the 25mm off what was there already. I just measured 25mm from one end and snipped with some wirecutters. This is so that the slides are a little quicker opening up when the throttle is cracked open. However even with the stock springs in there you shouldn't have that much of a hole at higher rpm. Did you cut the 1.5" hole in the top of the airbox lid? Maybe covering up the hole when the bike is colder to see if it helps. WHen the bike is warm it will be super rich but when colder it will be closer to what it should be. If it runs better with the hole covered up then you are too lean. If it runs worse you are too rich. Actually 1 shim does make a quite a bit of difference at least on my bike. I've tried 4 shims too and I lost quite a bit of roll on power with that tiny half mm shim. But even without the shim it should still be ok. Try covering up the hole, or some of the hole with masking tape and see how she goes from there. I have a 2005 myself.

However, If you trimmed the springs to 25mm overall length that is your problem. THe slides will dump fuel quicker than the bike will handle it. Fortunately slide springs are cheap. Pull a plug to verify. Even at idle vaccuum you will have the slides lifting slightly dumping fuel in the carbs. I can't remember off hand but I think the the slide springs are around 100mm or so after trimming 25mm or about a 1/4 they should end up at 75mm. If you trimmed them down to 25mm overall(wow) that would be your problem. Do you have the cut bits(longer spring bits) kicking around? You could put the longer spring bits(75mm or whatever) in which should be the right length and see if that cures your problem. I think you may have used the cuttings(25mm) in the slides instead of the longer trimmed spring(75mm). If your plugs are black then you definitely will know. When you crack the throttle do you get alot of black smoke?

If not you can order new carb springs for about $15 I think it was when I lost one.

The nipples on the float bowls are drainage nipples they aren't supposed to be attached to anything. Don't sweat it.

If the super short cuttings are the problem and it works fine after putting in the longer springs, take the bike on whatever highway is left in California for a good long run to get rid of any coke deposits in the engine. Lots of high rpm should clean out most of the coking.

NOTE: My measurements of 100mm is just a guess but it should be close to what a non cut spring is(about 6 inches). It's just to demonstrate that you need to use the longer bit not the shorter bit in the slides. If I get time today I'll measure one of my slide springs overall length as I've already trimmed them.

[txbanditrydr]

Spring cutting 101.....

... And the nipple caps refered to are vacuum inlets.  Carb #4 will have a hose connected to it that goes to the pair valve and petcock vacuum connection.

[rider123]

I think he said the float bowls txbandit. Let's ask. Do you mean the nipples at the bottom of the carb floatbowls with a screw above it? Or the nipples on top near the slide cap covers? If you loosen the screw on the bottom floatbowl nipples you should see some fuel dribble out. THe ones on the top are as txbandit says are vacuum lines for synching and #4 is for the PAIR/fuel petcock. I'm assuming since the bike is running it has been connected as the floats without getting any fuel would only run a minute or two before running out of gas. It seems your like 90% there it just something got screwy on the last little bit. I'd check those slide springs as that would do it.

My 112.5 mains came in so if I put them in this weekend I'll probably have to lower the needles at some point and I'll get you an exact length of what I have so you can compare. If you have the other bits of the spring that you cut they will be the right length so don't sweat it just put the longer lengths in and you should be good. I'm sorry I just don't have the instructions for the jet kit anymore so I can't say for sure without taking my carb caps off.

Worse case scenario, you could buy new slide springs and NOT cut them and pop them in there. Some guys on this board have done this with a holeshot kit on purpose to crispen up the throttle down low, though I think you lose a little mid-range.

[Johnny from Chicago]

Yep, I definately cut off 25mm and installed the longer spring portion. I'm wondering if the slides are opening too much too soon and causing the dead spot. The nipple I was talking about is the one on carb 3 on the bowl. I thought it was just open and not connected to anything. It must be pig rich because it ran OK when it was stock and too lean. I'm gonna pull the plugs then recheck the tiny "o" rings and the diaphragms in the top. If I find nothing wrong I'll set it back to stock and see if it clears up. If so I'll know it's not my install work but the settings. Also, I went beyond the 2" hole. I saw on Dales site how he cut out the whole airbox lid except for the retaining portion, so I cut out the top half of the lid where you're supposed to make the 2" hole. I'll try taping that up as well.

[rider123]

Thats probably the problem. It's supposed to be a 1.5" hole on a stage 1. THe picture on Dales site is a different kit in which he gives you a K&N and a modified airbox lid. Is this the kit you bought?(Different kit, I doubt it due to your main jet size) Or did you buy the one we all have which is the first model with the stock airfilter, 1.5" hole cut into the lid? What do the plugs look like? Are they dark and sooty? White and clean? Can the bike drive at all? Maybe taking it for a 20 min drive will at least mark the plugs up enough to read them.

If you cut the box as per the site picture on Dales site you will be super super lean, no wonder you would have a huge hole at 4k rpm. I'm surprised it would even rev up that high with the airbox that open with only 110 jets in there. Pull the spark plugs and see what they are like. I would guess that the airbox is so open there isn't enough fuel getting in there.


Here is a bad ascii diagram of what the airbox should look like with your kit.
 

          ----------------------              <----Top of airbox lid
          I           _             I
          I          /  \   <---- I  -------------1.5" hole cut in the top
          I          \  /           I
          ---------------------
          \                        /
           I         _            I
           I        /  \   <--- I  ----------------- Factory snorkel left IN(do not remove)
           I        \  /          I
           -------------------

Anything larger is going to lean the hell out of the bike. The picture on Dales site is for a different kit altogether. I would guess with that kit the mains would probably be in the 117.5 or 120 range to function correctly. If you are going to pop the stock jets in and plug up all the holes that would be a good time to check the float height. Make sure it's 13mm. In fact before you pop the stockers in there check the float height. Maybe it was like mine which were way too low creating rich loadup at idle. Once set to 13mm all was good.

Remember I'm actually set richer than you and I'm still a little lean up top and I only have a 1 1/4" inch hole in addition to the factory snorkel. You have over double the size! I'm suprised the bike runs at all with that amount of air going in there.

If the airbox lid is totally screwed don't sweat it I think it's like $40 at www.bikebandit.com but remember to follow the instructions for the kit you have. If you want a tip what I did to reduce the hole on my bike is I got a 2" round rubber washer and just cut out 1 1/4" hole out of it and taped it on there so when I get the new mains I just rip it off to get the full 1.5" since it's only taped on.

I'll tell you what I'll install the 112.5's on my bike tomorrow and I'll do some measuring for you and post it here so you can compare. I wouldn't give up you are basically %90 done you just went a little jihad on the airbox cutting. Try if possible to tape the entire portion of the airbox top so it's closed EXCEPT a 1.5" hole(and the factory snorkle of course) and see how it goes before you do anything else. If you wanted to just tape everything for now except the factory snorkle and see how it runs. It will get rich after a few mins of warming up but if it immediately runs better then you know what the problem is. I would order a new airbox lid so you can cut the proper 1.5" hole in the top, if the old one can't be salvaged.

[rider123]

K I'm in the middle of this job but here is the spring length after I trimmed it:

110mm or 4 1/4" at least around there I'm using a tape measure not calipers

[rider123]

Holy F@ck! I popped in the 112.5's and I almost crapped my pants with the amount of power I got out of it! I think I may have to wear Depends(R) undergarments just to ride this thing now   . 1st just short of 1/2 throttle is almost uncontrollable. 2nd at half throttle the front end gets very very light with it coming off the ground on any little bump. I'm scared to go past half throttle now, especially in the city. The roads are jammed pack on Saturday so there was no point going on a highway just to go 20 miles an hour so I drove around town on the roads I know would be at least clearer. I'll pull the plugs after the engine cools which will give me an idea of what it's doing at cruise/bombing around town but it feels awsome. I'm actually scared of this bike now, not that it was that slow to begin with. But now its almost ludicrously fast. I didn't change the turns out on the pilots still at 4 so I'm imagining cruise won't be burning up too much more than what it did before which I was getting crazy good gas mileage at least on the highway. I dropped the shims to 4 from 5 for now to test. I'll have to do some plug chops and see if it needs more or less needle but it seems pretty good. I ripped the tape off the hole so I have the 1.5" hole there now. Actually I think its a touch more as I had to cut it with a hacksaw and while pretty good I think it's a bit oblong. Also my pipe is a little more free flowing than the Holeshot pipe at 2" not 1.75" so I guess I just needed that little extra jet.

So here are my final settings for now Johnny I hope this helps:

Airbox lid with a 1.5"(ish) hole in the top plus the factory hole with snorkle in.

112.5 mains  4 shims(may change but very very close)

17.5 pilots  4 turns out from lightly seated

Slide springs cut to 110mm or 4 1/4" (was measured by a measuring tape not calipers)


For yourself I would try taping up the top until you only have a 1.5" hole and see how it goes. Let us know if you need any more help. I think you're like 90% there.

Here is a little tip if you need to change the jets without pulling the carbs entirely. If you can loosen the boots enough like your going to pull the carbs with the amount of slack with the cables you should be able to shift the carb left or right one carb width so you can take off the float bowls with everything attached. For example to change the right set of carbs, 3 and 4 I took off the TPS lead and the #4 petcock vaccuum tube and shifted the carb bank to the right enough so I could get an allen key under there and change the jets. Same thing on the left, just shift everything to the left and it will give you enough wiggle room to change the jets without pulling them entirely.

After taking the TPS switch off(throttle sensor on #4 carb) and the vacuum tube for the petcock you should be able to have enough slack with the throttle cables and enricher circuit cable still on there to wiggle them so you can get at the jets. You may have to move the handle bars slightly to give one cable or another a little extra slack but it saves a ton of work.


Also I took a look for you on the number 3 float bowl and yes there is a nipple there with a screw beside it. THat's a floatbowl drain nipple. I guess because it's an inner carb mikuni went the extra mile and put a nipple on there so you can attach some hose and drain the floatbowl out the side. Don't worry I don't have anything attached to it either.

[Johnny from Chicago]

Got out there to mess with it a little today. I'm on kid duty so no test rides today. I taped up the airbox and started it and it ran OK. No more miss at idle and the dead spot at 4k is gone. Then I took the tape off while it was running and it didnt change a bit. So I gues the airbox was not the problem. I wonder if all the float bowls were not full yet or a float got stuck and caused it to flood and temporarily drop a cylinder. Anyway it runs much better now. I let it idle for 10 mins and then revved it up. No flat spot or drop out but it has a lot of popping in the midrange, and my muffler spring vibrates when I rev it. (thats a new occurrence). I'm going to try adding one more shim to the needle as it sounds like a lean pop not like a blubbery rich pop. Now you got me wanting to go 112's with that message but I havent even ridden it yet with the 110's. Thanks for all the quick responses. I'll have my bike running right this weekend I think.

[rider123]

No no, ride it with what you have I'm just showing you what I ended up with as an example, every bike is different. THe popping at midrange will be reduced if the hole is taped up to only 1.5". Also your absolutely right an extra shim would help in that area as well. Good to hear all is well. Good luck and good riding!

[Johnny from Chicago]

Got to work a little on it. Added 1 shim more, making it 5 shims. 3 3/4 turns at idle. 17.5 pilot jets and 110 mains. Half of airbox cut open. Almost no pops at 4-6k in driveway now. Drove it. Runs great down low to 4k. Feels lean from 4-6k then pulls like a raped ape from 7k up. I feel like taping up the airbox or just having 1.5" hole is leaving power on the table. I think I need to go to 6 shims or 112.5 jets or both. I'm going to try the shim first since it's easier to do on the bike. If that's good I'll try the jet too just for comparison. Never happy with "just enough".