Honda-SOHC

sorry, yes that the one called dust cap but I am not sure it achieve the same function than the static one. I think the damaged one ensure no air leakage at the passage of the rod. so bit more than a dust cap. it is annoying to see that the gasket is still in productuin with the carbs rebuild kit but w/o these rubbers... maybe they are not so critical and would be fine w/o.
best,
mgy

Thanks,

Basically it is the tiny black rubber in the centre of the top cover and referred as 16014-300-014, hopefully visualized in pictures below.

The part assembly (top cover, holding ring screw and rubber) is discontinued and I suspect it would be even harder to find the rubber part. The repair kit only provide the gasket that goes inside the carbs.
Best,
Marc

ok, I feel better now... wires are fine but worth checking. then still my advice would be to check the needle clips are in the same position nbr 4. and check your jets are stock...

i went through the exercise and just discovered that i had one cylinder (usually running at 80-90defF coldest) with a clip at nbr 3 where all other were at nbr 4... i have been trying to tune this bike for a year now. went through pilots/mains/float levels. now my carbs are in a ultrasonic cleaning. 1/2 hour 45degC. you would not believe the amount of dirt these things accumulate over the years.

if you are stuck with ideas and have some spare time and do not know your carbs... go for the full mounty clean up. the only drawback is getting the spares to rebuild. cant find the rubber that goes on the top cap cover where the slide rods go through...

cheers
marc

I would still recommend to keep it at 1 turn just to make sure you are not cumulating issues. Do you have an easy start up? Do you know the size of main and pilot jets as well as position of the needle clip?

As in many cases, there often cumulating issues with something not working well. I just went through a full dismantling of my carbs and I can tell you it is worthwhile at least to make sure this is set up issue. Then it should be a one at a time iterative process to fix it.
Best,
Marc

Yes, I will probably do better taking a kit than going on a separate list of items even if I don't need all. My only concern (either way) is to make sure the spares are ad'hoc. I suspect there are many different versions depending on years, model and history of the bike... could be that my Keihin are not even the original ones. will check the ref of the carbs, thanks.

Humm, I guess you are suggesting riding the bike to a professional mechanic for a complete rebuild of carbs... I will check with my mechanic what would be the charge.
Thanks,
Marc

Thanks Chris,

This is actually the post that triggered my question initially... The post clearly debates about whether the measurement should be from the lip or from the gasket surface but the below text between the pictures seems to indicate the measurement should be from the valve in open position ''so the valve pin tip is just barely touching the float tang''. Doing the work on the spot with the carb mounted is not easy as you would not see when the tip is barely touching the float tang and contrary to the description, in my carbs it does not seem that I have any spring on the valve (it looks like it is gravity). I would be interested to know if the 750K1 should have a spring in the float valve. That may explain why it looses rev as I wait at red light.

Wrt the approach I have taken and which I am sharing with the forum to get some feedback, I am now pushing the float at the highest point so when the valve is in close position I make sure I still have some little gap between the float and the top of the carb (i.e. the float does not bang onto the top of the carb which of course would prevent full closure of the valve). I may have a level a bit higher but I think as long as it is not over the gasket (which I will notice as it will leak from here). The assumption I am making is that high level (but no leak) is not affecting the carburation as what is moving the full up into the jets is the suction pressure and the diameter of the jets (i.e. it does not depend on how much of the jets are immerged into the fuel)... Any further experience to share on that one?

Wrt to Dennis post and table, do you know what means 4 for the needle jet? Is it a length, diameter or just the level where the pin should be attached at the top?

Best,
Marc

Hi,

I am running 4 in 4 standard but I think I have no bafle at the end of the pipe. I also have velocity stacks but I tried as well standard air box without being able to get a steady idle between 1000 rpm to 2000 rpm.

If I go with moving the needle up via the pin, has anyone tried to change the pin set up in situe, I.e carbs on the engine? Is there an easy access from the top of the carbs?

It seems that my starting problems come from gas not accessing the chambers despite new slow jets. Few supporting symptoms are:

- I usually.need to open up the idle screw at cold start taking the risk to foul the plugs. I can run a battery load without any succes otherwise. No need to say the choke is totally useless;
- My starter is actually a can of carb cleaner that I spray like a full on the velocity stacks.

Rather than changing the needle height pin, do you thing using a bigger slow jets, say #42 instead of #40 could help?

Thanks...