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Honda spree over revs

Posted: Tue Jul 21, 2020 8:21 pm
by 33jstyer
hi everyone, I have a 1986 honda spree and last year I went to start it and it acted as if the throttle was stuck open. This year I've started to mess with it but have gotten no where. I replaced the throttle cable and I tried a reproduction carb. I have resorted to putting the original carb back on it but it still over revs. The only way I can get it to start is by taking the air boot off of the carb. I can get it to idle somewhat but its still high and it will rev and bog by itself without me touching anything. If I go to put the boot on, the rpms skyrocket. When I take the boot back off, it drops back down again but is still very inconsistent and higher than I would like. Any ideas are very appreciated.

Re: Honda spree over revs

Posted: Tue Jul 21, 2020 10:03 pm
by motormike
That bike has a vacuum leak somewhere. Find the leak is first thing.
Typically, spray carb cleaner on any suspect spots with engine running.
When engine rpm drops, or stalls, the spot you just sprayed is leaking.
Could be as simple as the hose to the petcock came off the intake. Good hunting.

Re: Honda spree over revs

Posted: Wed Jul 29, 2020 6:55 pm
by 33jstyer
after pulling off the carb I found that the rear vaccum line was very cracked. I replaced the line and now I can get it to start with ease and I can drive it with decent power. But the idle is still high and I have the idle screw tightened all the way in. Still a vacuum problem?

Re: Honda spree over revs

Posted: Wed Jul 29, 2020 7:31 pm
by Meatball
Screwing the idle screw IN makes the idle HIGHER...you gotta unscrew it to LOWER the idle.

Re: Honda spree over revs

Posted: Thu Jul 30, 2020 9:07 am
by bonesv
33jstyer wrote: Wed Jul 29, 2020 6:55 pm after pulling off the carb I found that the rear vaccum line was very cracked. I replaced the line and now I can get it to start with ease and I can drive it with decent power. But the idle is still high and I have the idle screw tightened all the way in. Still a vacuum problem?
The air/fuel screw is the somewhat smaller one. The idle screw is the throttle stop screw which does not affect the air/fuel ratio at idle.
The a/f screw turned all the way in tells me that there is a lack of fuel getting to the idle circuit be it by way of an over-abundance of air coming in somewhere not regulated or by way of a too-small or partially clogged pilot jet.
Do you have the air box installed and without any modifications, and complete with a properly oiled air filter in place?

Re: Honda spree over revs

Posted: Thu Jul 30, 2020 10:28 am
by 33jstyer
the stock airbox is installed. I swapped to a remanufactured carb and everything acts exactly the same. The screw without the spring makes the idle skyrocket unless it's tightened all the way in. The screw with the spring has no effect on it.

Re: Honda spree over revs

Posted: Thu Jul 30, 2020 12:04 pm
by Meatball
Theres probably an air leak. Check the crank seals.