Need help with tuning...
#31
Pardon me for skipping most of the content but I read something on the first page that required me to voice an opinion, so if I missed something I apologize in advance.
Anyhow, this whole "put a CV carb on, they are the best" is BS. I've ran CV's, Super E's, Mikuni's, Bendix, Linkerts and SU carbs and by FAR my favorite is the SU.
The SU is easy to tune so long as you actually research a little about how to do it. They are stone simple pieces that damn near anyone can work on. Not only that but I went from 32 mpg with my Super E to 50+ mpg instantly by putting the SU on. Just about the only gripe I have with the SU is the lack of leg room, therefore I put on an elbow intake manifold and have plenty of room, plus it looks cool as hell.
If you want to get rid of the SU I'd be happy to take it off your hands. Oh, and the SU is a CV type carburetor.
Anyhow, this whole "put a CV carb on, they are the best" is BS. I've ran CV's, Super E's, Mikuni's, Bendix, Linkerts and SU carbs and by FAR my favorite is the SU.
The SU is easy to tune so long as you actually research a little about how to do it. They are stone simple pieces that damn near anyone can work on. Not only that but I went from 32 mpg with my Super E to 50+ mpg instantly by putting the SU on. Just about the only gripe I have with the SU is the lack of leg room, therefore I put on an elbow intake manifold and have plenty of room, plus it looks cool as hell.
If you want to get rid of the SU I'd be happy to take it off your hands. Oh, and the SU is a CV type carburetor.
Variable-venturi, in which the fuel jet opening is varied by the slide (which simultaneously alters air flow). In "constant depression" carburetors, this is done by a vacuum operated piston connected to a tapered needle which slides inside the fuel jet. A simpler version exists, most commonly found on small motorcycles and dirt bikes, where the slide and needle is directly controlled by the throttle position. The most common variable venturi (constant depression) type carburetor is the sidedraft SU carburetor and similar models from Hitachi, Zenith-Stromberg and other makers. The UK location of the SU and Zenith-Stromberg companies helped these carburetors rise to a position of domination in the UK car market, though such carburetors were also very widely used on Volvos and other non-UK makes. Other similar designs have been used on some European and a few Japanese automobiles. These carburetors are also referred to as "constant velocity" or "constant vacuum" carburetors. An interesting variation was Ford's VV (Variable Venturi) carburetor, which was essentially a fixed venturi carburetor with one side of the venturi hinged and movable to give a narrow throat at low rpm and a wider throat at high rpm. This was designed to provide good mixing and airflow over a range of engine speeds, though the VV carburetor proved problematic in service.
Last edited by Mr. Wannabe; 06-21-2011 at 10:24 AM.
#32
Pardon me for skipping most of the content but I read something on the first page that required me to voice an opinion, so if I missed something I apologize in advance.
Anyhow, this whole "put a CV carb on, they are the best" is BS. I've ran CV's, Super E's, Mikuni's, Bendix, Linkerts and SU carbs and by FAR my favorite is the SU.
The SU is easy to tune so long as you actually research a little about how to do it. They are stone simple pieces that damn near anyone can work on. Not only that but I went from 32 mpg with my Super E to 50+ mpg instantly by putting the SU on. Just about the only gripe I have with the SU is the lack of leg room, therefore I put on an elbow intake manifold and have plenty of room, plus it looks cool as hell.
If you want to get rid of the SU I'd be happy to take it off your hands.
Anyhow, this whole "put a CV carb on, they are the best" is BS. I've ran CV's, Super E's, Mikuni's, Bendix, Linkerts and SU carbs and by FAR my favorite is the SU.
The SU is easy to tune so long as you actually research a little about how to do it. They are stone simple pieces that damn near anyone can work on. Not only that but I went from 32 mpg with my Super E to 50+ mpg instantly by putting the SU on. Just about the only gripe I have with the SU is the lack of leg room, therefore I put on an elbow intake manifold and have plenty of room, plus it looks cool as hell.
If you want to get rid of the SU I'd be happy to take it off your hands.
I'm not saying its better, I have no data to that fact, but I know its no worse than any other carb out there.
#33
I've started putting the top end back together today after receiving all my new parts yesterday.
New valve guides and seals, new pistons and rings, as well as all new gaskets.
I'm taking my time and checking everything to make sure its right this time. It will take a few days to get it back together.
I also decided to get a new oil pump. Figured it can't hurt...
Lee
New valve guides and seals, new pistons and rings, as well as all new gaskets.
I'm taking my time and checking everything to make sure its right this time. It will take a few days to get it back together.
I also decided to get a new oil pump. Figured it can't hurt...
Lee
#34
I've started putting the top end back together today after receiving all my new parts yesterday.
New valve guides and seals, new pistons and rings, as well as all new gaskets.
I'm taking my time and checking everything to make sure its right this time. It will take a few days to get it back together.
I also decided to get a new oil pump. Figured it can't hurt...
Lee
New valve guides and seals, new pistons and rings, as well as all new gaskets.
I'm taking my time and checking everything to make sure its right this time. It will take a few days to get it back together.
I also decided to get a new oil pump. Figured it can't hurt...
Lee
#35
If you get another oil pump, remember shovels are about volume and not pressure. High performance oil pumps don't do much good in most cases.
Second Mr. Rowdy's statement. Previously, I measured the angle to make sure it was 60 degrees between intake ports. This last time, I fitted the intake ports to my intake manifold. Worked a lot better and have a better seal.
Second Mr. Rowdy's statement. Previously, I measured the angle to make sure it was 60 degrees between intake ports. This last time, I fitted the intake ports to my intake manifold. Worked a lot better and have a better seal.
#36
#39
#40
Had a 73 through here last year was doing the same thing , knurled the guides , installed seals & new valves . Bike would start & run fine but would cut out or backfire when restarting after sitting a bit , always fouled plugs and lots of oil on top the piston everytime . Ended up being when the motor came up to running temp oil was getting past the guides & the guide holes in the heads . Had to ream the guide holes and go oversize guides to stop it , bike ran like a champ after . Older shovels with short reach plugs had issues with guides getting loose in the heads , something to keep in mind if you've done everything else
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