Author Topic: MileHigh Cafe (Read 13482 times)

Retro Rocket · « **Reply #50 on:** May 25, 2010, 09:14:30 PM »

Quote from: Jerry Rxman Griffin on May 24, 2010, 11:16:10 AM

MileHigh,

Hondaman is in the neighborhood. Run it by his place.

Jerry

As Jerry has said, if you are near Hondaman then go see him, if he can't help you no one can, he has even written a great book on these bikes....

Mick

Flying J · « **Reply #51 on:** May 25, 2010, 09:39:12 PM »

you can still shim up the needle with washers. you just have to buy the right ones. I bought some a few months ago but havent dropped them in yet.

rynanza · « **Reply #52 on:** May 26, 2010, 08:41:05 AM »

There was a recent post on here that might be of interest to you. http://forums.sohc4.net/index.php?topic=71245.0

MilehighCB · « **Reply #53 on:** May 26, 2010, 04:06:57 PM »

I just read that thread, looks like perfect directions on how to shim the needles. Gotta love this forum. Can't wait to do this mod and drill out the idle jets.
Thanks, keep ya posted!

wannabridin · « **Reply #54 on:** May 27, 2010, 06:30:47 AM »

if you can find a set of 77 PD card needles, they come with the slots in them. they're the only carbs that have this i believe. i have a set, and i must say, it's handy! but take MReick's advice, go buy you shims that are precision ground to a certain tolerance. i tried messing with shims i got at home depot on my old 96 f3, and i could never get it right! wish i had known about the zuk's shims back then!!

Flying J · « **Reply #55 on:** May 27, 2010, 06:58:39 AM »

I have a Home Depot shims in right now and the bike runs, but the shims dont fit right so i went a bought the right ones on line. Havent installed yet. I have a set of 77 needles. Thats what i tried first to raise the needles but for some reason could not get the bike to run or idle well with them in. Went back to 78 needles with shims and things were much better. I guess my 77 needles are bad. Here is a link to what you need so you dont have to go search the web.
http://www.motorcyclecarbs.com/Jet_Needle_Shim_Pack_12__P10478.cfm

I need to put in my shims. I still cant get my bike to idle right.

wannabridin · « **Reply #56 on:** May 27, 2010, 07:29:40 AM »

good find! well i didn't think about the needle taper shape being different from year to year... that's my only guess! or the needles could be worn out. how many miles were on the carbs?

Flying J · « **Reply #57 on:** May 27, 2010, 10:40:42 AM »

unknow miles off a parts bike.

HellFishTat · « **Reply #58 on:** May 30, 2010, 03:40:15 AM »

do you have the oil tank zip tied in place?

MilehighCB · « **Reply #59 on:** June 01, 2010, 05:10:39 PM »

Yes, the oil tank is simply zip tied in place until I fab up the custom oil tank. I know its a bit getto, but I will make something in time. I cut off the factory mounting tabs, because I knew I wanted a custom tank. For now, it works, but not going to be long term.

Answering a PM, the fuse box was bought on line, there was no local fuse boxes like that.

BTW, shimming the carbs and drilling the pilots, so hopefully this will be the key to my lean issue.
I found the drill bits at Hobby Lobby, no need to order online!!!
keep ya all posted!

MilehighCB · « **Reply #60 on:** June 03, 2010, 11:17:26 PM »

Updates,,,,,,

So first let me correct myself, I found the drills at HobbyTown USA, not Hobby Lobby.

I drilled out the pilot jets, from 0.35 holes to a whopping 0.45mm. I smirk at the whopping, but honestly you CAN see a difference. From almost no hole, to hey there is light coming thru there. My carbs were just cleaned and I knew the holes were open, but wow, you can really see how fast and easily they could get clogged.

Next step, my buddy had an extra set of 77K carbs laying around. Pulled the main needles (with clip positions) and set the clip position 2 down from the top.

Finally rejected the carbs to 130 mains from the 150's I was attempting...

I ran the bike with this setup, and the baffle in the exhaust. Good pick up, smooth power and no issues until about 1hr into my ride. Nice Colorado day, only 75 degrees or so and after sitting at a red light/construction zone (less than 5 min) the bike went into the lean state it had before.

Frustratedly I limped her home. I really thought I had my issue solved and could start to enjoy the bike on long rides with confidence.

I did make a change to the fuel line. I zip tied it down across the carb boot on number 2 carb. It had a rise in the line there, and trying to eliminate ANY potential fuel issues, I wanted to smooth out the fuel flow. Maybe wishfull thinking, hoping.....

I am going to change the plugs again and try to run the bike this weekend. Temps will be higher, mid 80's. so I will see it I have the issues still.

On a side note, one thing that has happened during all of this testing/tuning/adjusting issues is this. When I start the bike, choke on, first button push, fires right up, but smokes like a 2 stroke. It was happening before I did the idle jets and clip position. It goes away once I warm the bike up, but wow, its pretty bad at first. This bike has 9K miles on it and has never done this before. Could I have done something by over heating it , or upjetting it?

Anyway, more to come, ideas, thoughts, suggestions welcome.....
Thanks

MilehighCB · « **Reply #61 on:** June 04, 2010, 12:31:33 AM »

So after futher research (gotta love this forum) on my new clip position(able) main needles, it looks like I may need to reposition.

I was thinking to change the clip from 2nd from the top, to third from the top. Sounds like this will richen the mix.
Sound right? What about going 4 down from the top and see it this is too rich? I add this because I would rather run a bit rich and keep things safe and able to run the bike on a longer ride, then find that I am still too lean, and find myself in the position that I have to pull the carbs off again anyways....
thoughts, suggestions.......

Little_Horse · « **Reply #62 on:** June 04, 2010, 09:57:18 AM »

sounds fine, get her done. When tuning I usually go in one notch increments until I like it then sometimes if I have the motivation I make half notch adjustments either way to see if it makes a difference.

Flying J · « **Reply #63 on:** June 04, 2010, 10:55:27 AM »

Have you tried a wot plug chop? Its a good starting point to help verify that you have the correct mains in.

MilehighCB · « **Reply #64 on:** June 07, 2010, 09:12:38 PM »

Im finally RICH! well at least my bike is running rich!
So updates are these, thought I would go all out and try to determine if my bike is ever going to run too rich.

Drilled out pilots, to 0.45, put the clip position all the way to the bottom, and ran 140 mains.
Ran sluggish, went for good back country ride without stop lights and such. I could certainly tell the difference, it was no where near as fast, didnt pull hard, but also didnt have the same issue I have been dealing with.

So pulle the carbs again, pulled the clip up one position. Went for another ride. I am amazed how much better it ran with just a tiny clip position change. I didnt ride far, or stop at lots of lights, but ran well.

I have a haunting feeling that my issue or the bike not running well or showing signs of running lean may be vapor lock. I have read other peoples chats about it and it makes sense. The bike runs perfect until hot, pops an sputters, runs bad. Turn the bike off and a stream of small bubbles migrates up to the petcock, it weird looking. Not a big bubble from a high spot in the line, but more a "pressurized bubble flow".
My tank is supposed to have a vent in it, I asked Carpy about it, and others have said it does too. I have tried to just pop the cap when the problem occurs, and it doesnt change anything.
With my Carpy tank and older style 2 into 1 petcock, it is mounted on the right side of the bike, my K8 carbs have the fuel inlet on the left side, so the fuel line crosses over the carb boots and just behing the hot valve cover.
Today I got a bit creative and wrapped my fuel line in heat insulation material. Basic stuff you can buy to keep heat away from stuff.

So, again my hopes are to eliminate this issue I have been having, but I am begining to think it is not a matter of running too lean. It was nice to see black sooty plugs for once, not snow white ones.

Keep ya all posted,,,,,,

Flying J · « **Reply #65 on:** June 07, 2010, 09:54:11 PM »

What did you use to drill out the pilot? .45 is a 45 pilot?

MilehighCB · « **Reply #66 on:** June 07, 2010, 11:53:45 PM »

From what it said on the jet, it was a "35" or 0.35mm. Hondachopper site recommended a 0.45mm drill. They sell them on line, but HobbyTown USA had them. Buck each.

Flying J · « **Reply #67 on:** June 08, 2010, 12:01:56 AM »

Ill go have a look. There is a hobby town usa around the corner

MilehighCB · « **Reply #68 on:** June 08, 2010, 08:09:56 AM »

The drills were behind the counter, not in the open. The guy did a conversion as they were not in MM. He found the ones that converted over. At home I checked with digital micrometer,and they were the correct size.

On a side note of drilling out the jets. The Hondachopper site is excellent on telling you how to drill them. I was able to use Hemostats to hold the drill and simply spin th jet with my fingers. Holding the drill with Hemostats gave me the "hands on feel" of any binding. It was easy to drill out the jets, I had no problems at all. Yes, went slow and steady but it went pretty smoothly.

Like I said earlier, I was amazed at the difference in the hole that tiny drill made.
Hope it helps....

MilehighCB · « **Reply #69 on:** June 10, 2010, 04:14:48 AM »

Good news bad news......

So I decided to raise the clip off the bottom by one and leave the main jets as they are.
Went for a ride and bike responded so much better. Not flat and sluggish and I was able to ride the bike about 50 miles or just over an hour before the nasty problem showed up again, hence good news bad news....

I am pretty certain it is not a mixture issue, as when I look at the fuel line, there is a void of fuel.

I have trimmed the fuel line as short as possible, as to not have a large valley/peak. Insulated the fuel line from heat as much as possible. I emailed Carpy regarding the tank and the built in vent on the cap. Didn't get much to go on except maybe drilling a hole and putting a one way valve and vent tube. Awww, maybe not.....but could make it cool.

I know my vent on #2 carb is working, or at least when I have taken the carbs off, I drain the fuel from the bowls thru it, so it flows. (quick after thought...yes fuel flows out, but is there a one way check valve on the end of it?? maybe not allowing air into it??? my memory serves me as there is a nipple or something from the factory on the end of that factory hose.......thoughts....

)
My next idea is to vent the fuel delivery line itself. Put a Tee in it and run a vent line higher then the fuel line. While I do not know WHY I am getting a lack of fuel in the line, it is certainly there. I have tried to ride with the cap open, and when opening the cap after the "vapor lock" synario happens, there are no changes.

Another thought that creeps into my head is the potential of float height playing a role. I adjusted the floats based on not having fuel coming out the over flow. While I admit, and possibly I have created my own frustration by this, but is it possible that I have just enough fuel in the bowl to run at cold to warm temps, but then after the bike gets warm/hot there is not enough fuel in the bowls to fight the heat that the motor produced. I am not quite sure how sensitive the carbs are to the amount of fuel in the bowls. When I first got the bike running, there were a couple carbs that flowed out the over flow, so I adjusted the float setting to mimic the carbs that did not over flow. Again, maybe I have a problem, maybe I am grasping at straws.....

Any suggestions, thoughts concerns would be appreciated.
Thanks in advance....

Little_Horse · « **Reply #70 on:** June 10, 2010, 07:28:50 AM »

It sounds to me like your tank is vapor locking. The next time it does it pop the cap and see if it goes away. The reason I say this is because you mention no fuel in the line, or a lack of fuel. If it does report back and we will discuss solutions.

MilehighCB · « **Reply #71 on:** June 10, 2010, 07:26:41 PM »

I have tried popping the cap, and seeing if I get fuel flow. It does not change anything. When I shut the bike down, after a ride and when it has this issue, I notice at times a stream of tiny bubbles going from the carb to the petcock.

I would think that if there were pressure building in the tank, when I popped the cap, it would equalize and allow flow to the carbs like it did when cool.

I may try to line the outside of the tank on the bottom with heatshield, maybe the increased temp of the tank is effecting flow?

I want to check that tube that vents the carbs, maybe there is a problem with that. Can someone tell me if that should allow air into the carb or just vent out? Meaning shoud there or is there a one way check valve on it from the factory?

Thanks in advance.....

void909 · « **Reply #72 on:** June 10, 2010, 08:59:11 PM »

Man I don't really Know much about anything but i have been following the thread and I got an idea. When you get the bike home after your ride you should shut her down and switch to a different tank or one of those hangable gas jugs with fuel line and petcock. Even use different lengths of fuel line at different heights. See if it make any difference. At least then you can rule out the tank petcock and lines. If that makes no difference then at least you will know its not a carb issue.

MilehighCB · « **Reply #73 on:** June 10, 2010, 09:29:11 PM »

Thanks for the idea, that maybe a way to determine if its pre-carb or carb related.
keep the great ideas coming!!!

HedNut · « **Reply #74 on:** June 16, 2010, 12:24:25 PM »

Very curious.... so it's running out of gas in the engine/carbs? If I'm understanding correctly....
I have 2 thoughts on this....pardon me if I repeat anything somebody already said. But either your tank is causing a vaccume/vapor lock and not letting the fuel flow (but you said you popped the cap).

OR

Dirt... You say you have a new tank on there...but it doesn't take much to bung up orifices in the carbs. Perhaps a fleck of the new tank got in the line...? In the petcock orifices!?...messed up petcock rubber in the valve?? who knows, but i'd check that all the way into your carb bowls. One way of knowing if it's restricted gas flow...is that it will cruize around no problem (cause it can keep up with filling the carbs as per demand)... but when you honk on Bo-Bo for a bit....she runs the carbs dry and starts to loose it...dies.

Reason I say this is, time and time again...tinkering with old bikes and snowmachines up here...I've run into this symptom a few times (if I'm understanding you correctly)
1) Check your petcock for obstruction....take it apart...clean it, carefully reassemble.
2)fuel line...blow it out
3)Carb fuel inlet, rail...and main needle into the bowls..... blow em out, clean them....

4) Test....leave your bowls off the carbs (prop them over a clean bucket...for gas collection)....hook up the gas tank....turn on the petcock...gas should start coming out of each main jet with a good flow (push up each float with your finger) see if it cleanly stops the flow, starts....etc.

Just a thought....

Try that.

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Author Topic: MileHigh Cafe (Read 13482 times)