weisco 440 kit-good or junk??

[Jeff Campagna]

I'm looking to go big in my engine and was wondering if anybody can tell me about the 440 kit. I have a chance to get one at a good price. Also what cam works best for trail and dune riding. Thanks guys.

[Knips178]

I have the wiseco 440 kit with a high compression piston. It's being put in right now so i'll let ya know when it's done. But for a cam, your talking about two different types of riding that, to me, seem like you need different kinds of cams. a hotcam stage 1 works good for trails, but a stage 2 would be better for dunes i would think.
anyway i'm sure someone will pop in here to answer you a little better than me.

[H440exconfused]

Originally posted by Jeff Campagna
I'm looking to go big in my engine and was wondering if anybody can tell me about the 440 kit. I have a chance to get one at a good price. Also what cam works best for trail and dune riding. Thanks guys.


I have the Weisco 440 kit, w/stage 2 cam, ride trails mostly, but do ride dunes. I liked it at first, but then I had it ported and polished later, and added better valve springs, then the FCR carb and LOVE it now. I have been running it with no problems for a yr.

Make sure you use the cometic gasket kit, throw away the weisco gasket.

[Hondaluva]

The only prblem with the wiseco is that it is hard to get the advertised compression. Make sure you take a look at all the numbers for compression ratio before final set up. There is nothing wrong with the piston but if you use the wrong gaskets and are not careful you will end up with a slow revving slug. I was already to set my machine up and I found out that I would be running about 9.5:1 compression. With a thinner head gasket and hondabond on the base I got 10.5:1 with an advertised 11:1 piston. So just make sure you do your homework first.

[Knips178]

what your suppose to do is assemble it and torque it down and find out what the compression is at, then either deck your head to the right compression or if possible change the gasket to the proper height to achieve the right compression. At least that's what I found through all the postings i've seen.

[Jeff Campagna]

thanks for all the info, maybe the 426 is a better route with the stage 1 cam. I dont want to jeopardize reliabilty.

[SnellCRP]

You would be fine with the 440 and the stage 2. The only problem with the 440 kits JE, Ross, Wiesco, will all have the piston sitting too low in the sleeve at TDC so your squish area is larger than it should be and what happens is your flame front from the plug can't get into that area to burn the fuel and it just gets expelled as exhaust gas, which reduces compression and; therefore, reduces HP. To get the most out of your piston kit in a 400ex you should try to get your squish to around .035 which will require taking .030 off of the base of the jug and running full gaskets or you can just run thin gaskets. I like to run the full gaskets so I had .030 taken off the jug which put my squish at .036 with a 11:1 Ross 89mm piston.:)

I have the weisco 440 kit and I am very happy with it so far. I too havn't run mine yet, but I will start it tomorrow. Unfortunatly, it doesn't come with the rubber o-ring at the bottom of the jug and the copper gaskets for the exhaust. From what I hear, none of the other kits do either. I personally am glad that that the compression is a little low on the weisco kit. It is the displacement that gives you the torque, not the compression. Yes, it will not rev as fast, but on the trails and on the dunes that 1/8th of a second doesn't matter much. What does matter is the ability to crawl up that hill or giant dune with nothing but raw Honda Torque!:macho

[cals400ex]

Originally posted by SnellCRP
You would be fine with the 440 and the stage 2. The only problem with the 440 kits JE, Ross, Wiesco, will all have the piston sitting too low in the sleeve at TDC so your squish area is larger than it should be and what happens is your flame front from the plug can't get into that area to burn the fuel and it just gets expelled as exhaust gas, which reduces compression and; therefore, reduces HP. To get the most out of your piston kit in a 400ex you should try to get your squish to around .035 which will require taking .030 off of the base of the jug and running full gaskets or you can just run thin gaskets. I like to run the full gaskets so I had .030 taken off the jug which put my squish at .036 with a 11:1 Ross 89mm piston.:)


i assume the small amount of timing that is off from shaving the base isn't noticable? anything to do to get that where it needs to be?

Well the weisco 440 kit started right up! I am extremely pleased with the result. I ran it mid range today, but when I went to turn around, the torque spun that quad like a dream! I can't wait to kick it loose and doughnut until I'm dizzy! I'm not going to baby it durning break-in. I really want the entire ring to seat against the cylinder wall. I hope this school of thought is the right one.:cool:

[SnellCRP]

I am not exactly sure what you are talking about with the timing, but taking .030 off the base is no different than using thin gaskets and as far as the timing chain the tensioner takes up the slack. I may have misunderstood the question though so let me know if I did. :)

[cals400ex]

Originally posted by SnellCRP
I am not exactly sure what you are talking about with the timing, but taking .030 off the base is no different than using thin gaskets and as far as the timing chain the tensioner takes up the slack. I may have misunderstood the question though so let me know if I did. :)


i think the timing will be off by running thin gaskets, shaving the base, a stretched timing chain, etc. however, it probably isn't enough to matter but i thought i would ask.

[nasty88r]

Who makes the thinner gaskets??

[SnellCRP]

When you shave the base of the jug the chain would get more slack because now the cam sprocket is .030 closer to the cases and the tensioner takes up the difference. As far as the gaskets go when you want to run thin gaskets you just take stock 400EX gaskets and take the top layer of the gasket off of the rest of the gasket. So you will actually end up with 3 pieces 2 thin steel gaskets and the fiberous middle gasket. You use one of the thin steels for your head gasket and no base gasket just some type of gasket maker. I don't run my engines with thin gaskets just because I like to not have gasket problems, but someone who does run thin gaskets would be able to tell you better what to use for a base gasket.;)

[Hondaluva]

Who makes the thinner gaskets??


Cometic Gaskets (440)354-0777

They make a .027" stainless head gasket and also a .010" stainless head gasket.

[nasty88r]

So do most people use the .010 or the .027 or do you have to check the clearance for each specific bike??

[Hondaluva]

Well, it depends on a lot of things. Mostly the squish and the deck height.

The Squish Band or "Quench" is defined as that area between
the flat of the piston and the flat of the cylinder head at
top dead center (TDC). On the compression stroke, as the
piston approaches TDC, the compressed mixture of fuel and air
is "squished" to the remaining space of the combustion
chamber where the spark plug and valves reside.
The "squeezing" of the mixture creates turbulence and is
expected to promote a better and more complete combustion.

Deck Height: The distance between the flat "quench" surface
of the piston and the top of the bare cylinder (no head
gasket). Typically an engine is set to zero deck height with
the head gasket (compressed value) defining the "squish band"
value. If the value is negative this indicates the
piston's "quench" surface extends above the top of the bare
cylinder.

Once you determine those measurments you need to use a compression ratio calc. to figure out what your CR will be. Then you can start to adjust the gasket thickness.

Most agree that the proper squish band for a 400EX is .040".

It may sound complicated, but it is a MUST for the proper final set up.

Oh, and I see that made a mistake. Cometic makes a .010" BASE gasket, not head gasket. Sorry about that!!

[RED121572]

Ive got one of their 12.5.1 kits. No problems on my end. Itll climb a tree with little problem.:eek: