Hey guys would love some feed back on this. bought an 82 cb750 with air pod filters, and i stress did not come with original air box. long story short couldnt get the bike to idle. re jetted it , and cleaned/ rebulit the carbs . finally got it to idle but after reving the bike then idle hangs around 2300. im pretty mechanically inclined but these carbs are giving me a run for my money. was told if i get a carb sync tool thatll help. im a new rider of 3 years and askimg if you vets can help. will send attach vid.
Hanging idle 82 750 airpod filters
- Thread starter lkanellis
- Start date
81cb750f
CB750 Member
I've never used pod filters but have heard that they can result in a lot of grief in getting the bike to run properly. I would try getting a stock airbox. Regardless, pods shouldn't affect idle too much. I agree with getting and using a sync tool and would suggest getting the Carbtune Pro Sync tool. BUT, you should check and adjust a few things first before syncing: valve clearances, timing (static), plugs, cam chain tensions, and the four pilot screws, one on each carb. For the pilot screws, check how many turns out they are. These things affect idle to a significant degree as they change the air fuel mixture at idle and when the throttle is slightly open. You should remove them and make sure they are clean as well as the passages, and that they have all the required parts. Careful, there is some pretty small parts (washers, o-rings, springs, etc). Then you turn them all the way in until they LIGHTLY seat. I stress that because they are fragile. Then turn them out anywhere from 1.5 to 3 turns. Most common opinions seem to be 2 or 2.5 turns. There is a long complicated procedure called the idle drop method in the service manual to adjust these to the right turns but it is very difficult and time consuming as not all pilots are very accessible (1 and 4 are, 3 less accessible, but two is tough because the starter and cover is in the way). As a result the bike can be idling for a long period of time, running hot, as you try get your hands under the carbs to turn the screws (unless there is a special tool for this). If you do attempt I would recommend having a fan pointed at the front of the engine and hook up a digital tachometer as you have to turn the pilots in or out and wait for increases/decreases in rpms of 50.
BAHNST
CB750 Addict
Make sure you have no air leaks at the manifolds....
re tool for the carbs there is a honda one-which I believe is often sold as a "CBX1000 tool"...or the motion pro-that i use cheaper...
https://www.motionpro.com/product/08-0119
re tool for the carbs there is a honda one-which I believe is often sold as a "CBX1000 tool"...or the motion pro-that i use cheaper...
https://www.motionpro.com/product/08-0119
Thanks for the info ! theres a couple of things i now need to check. what i didnt mention in the precious post was that ive replaced all gaskets and thuroughly cleand the carbs. raplaced all floats etc. all idle scews are at 2.5 turns . besides rhe carb syncing im wondering if leaky boots connecting the carb to engine could be an issue? doesnt seem like that would be , but to be honest what do i know lol. also wondering if the needle air floats are getting hung up. idles fine now but when i rev it, goes to 2300 rpm and stays until i put it in 1st gear then immediatly comes back down. im def overlooking something i feel. would love to get this bike going bur i fear it might be above my capabilities. i tried attching a vid in my previous post but dont see it now. will try again. in vid it seems like the number 1 exhaust is hottest followed by 2 3 4 getting cooler . lol prob a different issue lol. thanks again for your knowledge and insight !
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