carbs 74 to 78

chilliwackwestie · Full Member Joined: Sep 26, 2008 Posts: 37

Are the carbs on a 74 the same or different than the 78 carbs ? if so which one is better.
Cheers

jayel · Posted: April 12, 2009, 8:57 am Post subject: Re: carbs 74 to 78

same basic carb, jetting differences and later carbs have the bar mounts acrossed the bottom to hold them in posistion better, most internal parts are listed as fitting 70-79,

xs1961 · Posted: April 12, 2009, 9:20 am Post subject: Re: carbs 74 to 78

Earlier the better as far as UK carbs are concerned... we got 38mm jobbies ,78 carbs shrunk to 34mm.

jayel · Posted: April 12, 2009, 11:13 am Post subject: Re: carbs 74 to 78

think we when to the 34's in 80 here in the states 61, but they always did like us better Razz

except for xsjohn, they knew he was going to get a 80 so they switched Laughing

xs1961 · Posted: April 12, 2009, 11:21 am Post subject: Re: carbs 74 to 78

..Actually youre right, 80 it was... Embarassed

..
something to do with US emissions/fuel saving ?

jayel · Posted: April 12, 2009, 11:42 am Post subject: Re: carbs 74 to 78

yes our beloved EPA (Enviromental Protection Agency) you can bulldoze the top of a mountain to dig coal but by god your not going to run your engine rich enough to not burn up!

xsjohn · Posted: April 12, 2009, 11:51 am Post subject: Re: carbs 74 to 78

You knew I couldn't resist....

Yea……was a Gov’t emissions problem not a carb problem………BS34 basic design was good until the Gov't decided to tkune carbs…...when I first got my 80 it got 55-56 to the gallon…..was so lean I don’t know how it kept from seizing…couldn't ride it anywhere…now it runs perfect and a lot richer and still gets 55-56 to the gallon…..have to wonder what the heck they were thinking……the electronic ignitions were also a bit advanced to keep with emissions standards…..add them both together and it was a total disaster…….fix the problems and you are on your way…and riders and even most so called mechanics couldn’t figure how to straighten this out so a poor reputation developed……nothing has really changed there as I can see…….. Laughing

xsjohn

Retiredgentleman · Posted: April 12, 2009, 12:23 pm Post subject: Re: carbs 74 to 78

chilli;
This is a very useful table, when you start looking at carb internals.
5twins gets credit for this table.

weekendrider · Posted: April 12, 2009, 12:52 pm Post subject: Re: carbs 74 to 78

The '74 had dual throttle cables? 78 a single.

xsleo · Posted: April 12, 2009, 6:12 pm Post subject: Re: carbs 74 to 78

They changed over to the single cable in 76. All the earlier models had dual cables.

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