Honda Spree and Elite 50 Forums

Vintage was right.

Since i replaced mine with the correct year 84-85 instead of the 86 bystarter its been running like it should . not more spattering while WOT. Nice and smooth

The vacuum bystarter test is so very important to diagnosing carb problems.

Vacuum pump tester=$118....whole new bystarter=$25....I made an executive decision to save myself a Benjamin and replace a 30yr old part at the same time. If I wanted to spend that much I would buy a new carb and be done with it. If I keep throwing money at this thing like I have been, just trying to get this bbk to work right, I could've just bought a new 2016 Honda. The whole reason I have this is because I got it for cheap, parts are cheap and I can save money by fixing it myself. However, once the cost of parts reaches 5x the purchase price and my repair-time exceeds ride-time by 10 fold....Im peeling the VIN numbers off this pig and ghost riding it off the nearest cliff. OK, rant over.

Bad executive decision..

All you have to do is get a blow gun at Harbor Freight for $4 like the one referenced in the link below and wrap the end of it with a turn or two of masking tape to make a good seal. Then hold it against the hole in the carb intake referenced in the manual. Then see where the air comes out when you hit the trigger. Then hook the bystarter wires (while it is installed in the carb) to a battery and repeat the test while the bystarter heats up. It will take less than a minute and you won't be able to blow air through the hole if the bystarter is working properly. If the bystarter is working properly, you can save the $25 on a new one.

If $4 is too much, do the same thing with a small plastic soda straw, narrowed down to fit in the hole, and blow into the straw. When the bystarter is cold, it will be easy to force air through the hole. When it is hot, you won't be able to blow through the hole.

see:

http://www.harborfreight.com/air-blow-g ... 68258.html

Vintagegarage posted this last year, but I did not see it until now. I have had zero problems between early and late Spree bystarter interchange. I have not seen a "step" cast into 84/85 carbs that could hang up the bystarter air valve.

Can you post pics of what you see?

vintagegarage wrote:The carbs that I have that I think are 1985 carbs have a "step" cast into the side of the bystarter chamber that limits the downward travel of the bystarter's brass piston, while the carbs I think are from a 1986 or 1987 have no such "step". I also think that the brass piston in 1985 bystarters have a different "cold" position than the 1986 or 1987 bystarters and if you try to force a 1986 bystarter into a 1985 carb, the brass piston will hang up on the "step". In other words, using a 1986 bystarter in a 1985 carb won't work even if you cut off the two prong plug and replace it with bullet connecters, and likewise if you use a 1985 bystarter in a 1986 carb, the brass piston will be in the wrong position when cold.. Am I all wet, or is any of this true? I don't think I have ever seen mention of this in this forum, so I assume I am probably wrong?

-- Supporting Photos The Carb body casting air valve bore is smooth all around. The bystarter air valve 'tube' bottoms out at an effectively closed position

vintagegarage wrote:I also think that the brass piston in 1985 bystarters have a different "cold" position than the 1986 or 1987 bystarters and if you try to force a 1986 bystarter into a 1985 carb, the brass piston will hang up on the "step". In other words, using a 1986 bystarter in a 1985 carb won't work even if you cut off the two prong plug and replace it with bullet connecters, and likewise if you use a 1985 bystarter in a 1986 carb, the brass piston will be in the wrong position when cold..

I've put together an optical comparison to show the machined valve passage as well as bystarter mounting points has no noticable change between 1985-1987

1) Take a reference photo of both carbs to the same scale 2) Copy and shift on carb (1985) on top of the other (1987). Set transparency such that both are visible.
Leave horizontal shift preset so each carb can be seen.

Any height difference of the machined height of the air valve passage or bystarter mounting will show as a vertical double image.

Sorry to say, my camera isn't as good as the one mouswheels has, but hopefully these photos will be good enough. The red arrow points to the step in the bystarter chamber that will keep the brass cylinder from going all the way down. Ignore the fat red arrow in the brown area to the right of the photo. I made a mistake editing the photo.



Hopefully the explanation is in the part numbers of the two carbs. The one on the left without the step is 29HAAA with a horizontal T at the end. The carb on the right with the step is part number 29MAYI with an odd character at the end.



based on mousewheels research, I presume the carb on the right isn't a Spree carb, although it came on a 85 Spree I bought, and I assumed it was original.. I guess it wasn't.

Vintagegarage wrote:The red arrow points to the step in the bystarter chamber that will keep the brass cylinder from going all the way down. Ignore the fat red arrow in the brown area to the right of the photo.

Thanks, pic is helpful. The location and shape of the bump resembles a carb damaged by mounting bolt contact.

I looked at that carb again using mousewheels info and he is right. That bulge was caused by somebody inserting in too long a carb mounting bolt I'll edit my original post so that it won't cause confusion for somebody in the future doing a search on "bystarter". Thanks mousewheels!