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slightlybent47
10-07-2009, 07:27 AM
Hi! everyone this is my first post: I have been reading the thread on the 450 carb on a 400ex so I now have in hand a used 05 450 carb.

Now from what I've read I need to get a 450 throttle cable and I'm assuming that is because it needs to fit the hole where the cable screws into the carb. Will the throttle lever side still fit the thumb throttle?

Then I see the vent tube and it looks easy to take the top vent and move it to the side. What size screw and tap should I use?

Next I don’t need but I want to get a sprat intake boot so I don’t have to alter the old one. The reason I want to have a sprat intake boot is if I don't like the 450 carb mod then it will be easy to just take off the 450 boot and all and put the old one back on.

Next can I just leave the hot start on the 450 carb and not use the hot start plug? Or do I need to plug it off with a hot start plug from Honda?

I'm going to try to make my one adaptor for the stock 400 air box but if that don't work then I may order that adaptor that the guy has put on the other thread. Has anyone ordered one and did it work? Is he a good seller?

Next there is a hole with threads next to the hot start leaver and it looks like something is missing. What goes there? Here is a pic below.

Here is my plan: take the quad with the stock carb and put it on the dino and test it and tune it up as best as the 400 carb can be.
Then get a read out and see where the power is with the stock carb is.
Then with the 450 carb and new boot it should be fairly quick and easy to remove the old carb boot and all and put on the new 450 carb and new boot then tune and run the same test with the new carb set up and then I can see if I got any real gains from the mod.

Witch brings me to another question, Do I need to get a gasket for the intake boot?

I think that’s it, please if I missed something let me know and thanks for your input.
http://i35.tinypic.com/mux08x.jpg


The bike has been bord to a 416, with 12:1 pompression.
Recreational P&P with a stage two hot cam.
Stock head pipe (PORTED) and a white brothers MX4 slip on pipe.
The stock carb has been jetted and the ckoke removed.

This should finnish the build for now.

slightlybent47
10-07-2009, 07:48 AM
I forgot to ask what jetting should I start with on the 450 carb?

Thanks

supertrooper90
10-07-2009, 08:16 AM
I just bought the 450 adapter. It seems like it will work just like he says. He is a great seller. got my part in like 2 or 3 days. The yellow lever is the choke. the hole next to it is for the hotstart. that needs to be plugged.

slightlybent47
10-07-2009, 08:27 AM
Originally posted by supertrooper90
I just bought the 450 adapter. It seems like it will work just like he says. He is a great seller. got my part in like 2 or 3 days. The yellow lever is the choke. the hole next to it is for the hotstart. that needs to be plugged.

Ok thanks I don;t know why I was thinking that was the hot start.
Let me know how the adaptor works out.


Thanks

Bill Martin
10-07-2009, 04:34 PM
I;m about to do the same mod, please let me know how it works.