Mikes keihin carb kit

[rude]

G'day Bruce, I've got a standard 78E, answer to your question is no, some modification to the sidecovers is needed to fit around the pods

 

[bruce_46]

Anything major?

 

[rude]

Re shape the opening on the sidecover where it fits over the standard airfilter rubber boot, to keep the standard battery and electricals I decided to make my own, pic below, since the pic I've painted them satin black

 

[bruce_46]

Nice look. I don't think I want to cut much of the side cover off though in my case. This project I'd. Still like to keep it looking reasonably original. I'll make a new battery tray etc though anyway co I want to use a much smaller dry cell battery.

 

[Henkies]

Hi there, I still try to improve idle with the Keihin Set.The most improvement i made was to connect the vacuum tubes, so you only need one choke.When I was thinking things over i noticed that the right carb has a screw the left one has not. What does this screw do?

 

[mrriggs]

Hi there, I still try to improve idle with the Keihin Set.The most improvement i made was to connect the vacuum tubes, so you only need one choke.When I was thinking things over i noticed that the right carb has a screw the left one has not. What does this screw do?

That screw is just a plug. The carbs are originally made with the idle screw on the left side. Since that would be awkward on a dual carb setup, the right carb is drilled and tapped to put the idle screw on the right side.

 

[scarface6477]

hey guys im trying to get these carbs going right but im having a few problems. im also not to familiar with anything other than cv type carbs. 1st issue is idle. when we start the bike cold , the idle races without any choke and without blipping the throttle. i thought that the slides were sticking but im not giving it any throttle so the slides shouldnt be opening. as the bike warms the idle drops a bit. without giving the bike throttle or ckoke why would the idle race? 2nd question is how does the idle thumb screws work. how do i raise and lower the idle? it does not seem to effect the idle when turing in or out. 3rd issue is the air screw. so this is an air screw? not a fuel mixture screw? does backing the screw out give more air? or turning the screw in restrict air? thanks in advance!!!!! Ive been reading through all the info but still cant find an answer to my first question. thanks.

 

[mrriggs]

If the idle is racing and the idle screws are not working then you probably have the cables too tight. You need to have some free play in them when the throttle is closed.

Yes, the air screws meter the low speed air bleeds. Screwing them in makes it richer, turning them out makes it leaner.

 

[scarface6477]

thanksa riggs! hopefully will do the trick. allo. like others have hAd happen, the rubber intake boots have begun to crack. i think i read somewhere that stock ones will work. you ever hear that?

 

[gloucesterfd]

Hi all, im having a problem with one of my carbs over flowing through the vent tube in the bowl. i have had this problem for a while. i recently installed a new float and needle and it stoped for a few weeks. I had to pull that carb off yesterday to repair a torn boot, reinstalled the carb and went for a test ride, now it is overflowing agin. anyone have any ideas why this is doing this and what could be done about it? anyone had this problem?

Thanks,
John

 

[Eckl]

I just fired mine for the first time and the left side overflow runs constant too. Was looking for an answer as well


Also, when I perform the dead cylinder method to adjust the idle, I cannot not seem to get the right carb to idle down. Slack in line and slide all the way to bottom visually. Left side idle... no problem.

 

[rude]

Initially I had the overflow problem on one carb, upon closer inspection I found that the fuel wasn't coming from the overflow but rather from where the bowl meets the body, the gasket was not seated correctly in the channel in the bowl, worth checking. For fast idle problem, check that the cable is seated correctly in the slider, on one of mine it was not seated correctly causing fast idle even though it all looked good from the outside
cheers

 

[Eckl]

Mine is leaking from the overflow for sure. I connected the supplied hoses and routed it to underneath the bike. Any other leaks would show up top then. Good idea though!

 

[gloucesterfd]

I solved my problem for now. I pulled the #1 carb off this morning and took a look at the needle and seat. there were 3-4 small pieces of trash sitting in the seat. i cleaned the seat and reinstalled the float and needle, put it back on the bike, fueled it up, and no leaks. if anyone out there is not running a inline fuel filter, I would advise you to. untill today i was relying on the screen that is on my harley petcock but found that to be insufficient. Hope this helps anyone with the same problem.

 

[Eckl]

I'm off to the garage to check mine!! Hopefully it's just some crap in there, I do run a fuel filter though.

 

[Eckl]

So I found the float binding on the overflow tube. It was actually stuck in there pretty tight. I had to pull hard enough to free it that I was uncomfortable with the force I was using. Either way, I squared up the floats and set my overflow from 20mm to 19mm.

Also found a how to page here: http://scootrs.com/tech.cfm?tip=float

Cheers!!

 

[brat]

Tried everything to get these dialled in properly. mixtures are a nightmare to tune for me. Runs really rich even with the extra jets supplied. can't get it.

I use to get 240km per tank on my stock carbs with pods, boyer, straight pipes (small baffle) now get 95km. Going back to stock for now. giving up on these.

 

[malloym]

yea, i'm trying to get my dialed in.. I can get the bike to idle, but will die when trying to criuse or accel.. also get alot of popping and jerking.

 

[Eckl]

I'm having idling issues. Pops BAD on the right cylinder, then the plug fouls. Slides stick terrible, consider this pretty dangerous. Wish I would've have sprung for something different.

 

[mrriggs]

I'm having idling issues. Pops BAD on the right cylinder, then the plug fouls. Slides stick terrible, consider this pretty dangerous. Wish I would've have sprung for something different.

Yeah, you're not alone. You have two options; cut your losses and throw the whole mess in the scrap bin, or replace all the defective parts and try to make them work. I got sucked into option 2. After spending so much money on them I couldn't justify throwing them away, and in good conscience couldn't sell them to anybody else. After getting all the bugs worked out, I am quite pleased with how they perform. It always starts on the first kick, idles flawlessly, and has violent throttle response.

When I first installed the carbs they were running rich, wouldn't idle, fouled plugs, lurched, spit, sputtered everything that so many have described. When researching jetting, I discovered that the slides, needles, and air bleeds were all the same as an off the shelf 2-stroke carb. The only difference is the jets which were made smaller to try and compensate for the overly rich needles. Too small, in fact, for the bike to idle correctly.

What made a world of difference with these carbs was stepping up the needles. I've gone up six sizes from what came in the carbs and still think it may be a tad rich. With larger (leaner) needles you can then step up the slow jets so it will idle correctly. The slow jet/air screw will effect the transition but they are the only way to adjust the curb idle. So you need to set the idle with the slow jet/air screw then not touch them. With that locked down, the only way to change the transition is with the slide cutout or needle diameter. Replacement slides are really expensive so your only other option is the needle diameter. There are no replaceable air bleeds, leak jets, or needle jets on these carbs so the needles are all you have to fine tune them. The diameter tunes the transition, the clip position tunes the cruise/part throttle. So, all-in-all these carbs are really easy to tune, once you get the sticky slide problem resolved.