280 lbs. 750sx-f build

[Waternut]

Mod the engine and put the freakin total loss in... Go to Lowes and get a drill bit and tap. All total loss setups require case modification. You'll always wonder what it would've been like if you had put it in so you might as well do it while you still have it. Unless you can spot an MSD setup for fairly cheap...

Why does the hood need modification for the chamber? Mine fits with tons of room.

 

[sxi4evr]

well ya know on the case where the pickup plate is supposed to mount theres some edges molded in which kind of give like a radius around the center of the crank, well the radius of that doesnt match the radius of the pickup plate. also, the flywheel comes out too much and hits the ignition cover so i would have to mill it. hard to explain...but ya. it doesnt work:rant:

and the hood was modded from the guy who had it before me, he put a piece of pvc in where the big black stock air intake was and it hits, just a quick hack saw job :Banane09:

im thinkin im done puttin money into this thing and from here on out im goin truck and then sj :dance:

 

[Waternut]

well ya know on the case where the pickup plate is supposed to mount theres some edges molded in which kind of give like a radius around the center of the crank, well the radius of that doesnt match the radius of the pickup plate. also, the flywheel comes out too much and hits the ignition cover so i would have to mill it. hard to explain...but ya. it doesnt work:rant:
:

Yeah the flywheel cover has to be shaved down. How far off does the pickup plate mismatch the case and do the mounting holes mismatch as well?

 

[sxi4evr]

i think the mounting holes would have worked but with the case not lining up it couldnt of been clamped down. did you have to shave your cover for the msd?

 

[Waternut]

Well yes and no... The MSD system requires shaving the flywheel cover but I bought a cover that was already shaved down.

 

[sxi4evr]

so i got it all put together today and started by 3 with some breaks and trips to tractor supply for clamps an home depot for bolts. It started in about 10 secs of cranking :biggrin: then off to the lake :headbang:

the lake was cold!!!! it was about 40 and cloudy all morning so i wasnt gonna go but it warmed up to about 50 and the sun came out so i decided to go. Tomorrow should be warmer.

I sucked, :1244: i almost fell like 5 times just turning and i flipped over and was dunked under water trying just a 180 turn :bad3: then beore i could get back in the saddle she stopped pissin water so i killed it and swam it back. i forgot to tighten the bolts from the manifold to the head pipe, no biggie

 

[sxi4evr]

vid: i deffinitley need to tune it...too lean on the bottom

pics: yeah

 

[BruceSki]

the pole looks way shorter than the old one you had on there.

did you notice a difference with that? good/bad?

i give you props riding in cold ass water... i did that last year cause i was excited after i spent all winter building my ski up.... this year f that... i hate cold water. ill be out mid-end of april depending on the air and water temps.

i think two weeks ago the temp at the inlet of the ocean was 37.... thats frostbite/hypothermia cold.


hope you get it running correctly soon so you can enjoy the summer

 

[Waternut]

i forgot to tighten the bolts from the manifold to the head pipe, no biggie

Two things...

First, I remember you ported the motor. Did you hone the cylinder and replace the rings or just leave it alone? If you put new rings in, it didn't look like much of a break in.

Second, if your head pipe bolts were loose, you will immediately see a massive improvement once you tighten them down. So it may not be carb troubles but I don't know. I didn't touch my carb when I ported it on my 750.

 

[sxi4evr]

ya the i like the pole way more, once i get used to ridin again i think it will deff be to my advantage!

i did hone it and they are the old rings, and remember, its a different pipe too. but i'll see what its like today. i'll get some more video of how it goes

 

[sxi4evr]

current mod list...
hull
wammer footholds
wammer turf
cut rear bond rail
hood mods with handholds
handling
-2 sj pole
lowered bracket
2 inch breather tube
UMI steering system
Blowsion shortened conversion turnplate
Blowsion 0* bars
D cut R&D rideplate
PJS scoop grate

performance mods
sport port templates
MSD enhancer
Factory limited pipe with jetcraft turbomuff
R&D intake mani. with R&D reeds and stuffers
wsm .5 over pistons
new cylinder and bore
sbt crank-
mikuni 46 sbn
skat-trak 10/18 prop
stubby pump cone
a little before and after for the ski...

 

[N3vrSat1sfied]

remember that that cold of weather will affect your jetting as well! Colder the air the leaner it will run

 

[sxi4evr]

ya, i learned that doin nitro rc car engines. those little engines are super sensitive.

its 50 deg. right now and is supposed to warm up later on so when my dad gets back from flyin his rc planes im off to the lake!!!

 

[Waternut]

i did hone it and they are the old rings, and remember, its a different pipe too. but i'll see what its like today. i'll get some more video of how it goes

New hone and old rings may bite you in the @ss...:nutkick: I wish you the best of luck though.

 

[sxi4evr]

a quick edit...

adjusting the carb didnt do much for bottom end tuning the pipe is what i'll do next. :Banane09:

 

[Waternut]

I wouldn't consider that video running like a dog. Running like a dog to me is when I can barely get out of the water. Either you held the throttle during one of those jumps or it started racing... If you didn't hold the throttle, it's either really lean, the idle is really high, or you have an air leak. Did you pressure check the engine after putting it back together?

 

[sxi4evr]

well i was riding around with the throttle about half way in, it makes all of its power going from mid to high and takes a sec for the revs to get there. i think i might of been holding the throttle in...my finger was numb after about five min. of riding with thick work gloves on.

and no, i didnt do a compression check cuz my compression checker is crap, but it deff. had comp...i couldnt turn it by hand. and also its got all new gaskets on the top end.

 

[Waternut]

and no, i didnt do a compression check cuz my compression checker is crap, but it deff. had comp...i couldnt turn it by hand. and also its got all new gaskets on the top end.

No no... I'm not talking about compression testing. I'm talking about an engine pressure check. It basically ensures that the crankcase, intake, base gasket, crank seals, etc. are sealed up properly. You basically pull the pipe and carb off, install test plugs or something in the carb and exhaust manifold and pump up the engine to 7-10 psi through the pulse fitting and see if it holds pressure. Do a search on it... If the engine has a tiny air leak, you'll never be able to tune the carb and it'll run like ass on the bottom end because that tiny leak is messing with the fuel/air mixture. The problem goes away at higher revs because you're pumping so much air into the engine that a tiny leak isn't going to affect you much. I know you don't want to pull the engine again but a small air leak in a 2 stroke is a serious issue that can lead to seizure. I've rebuilt both of my engines and both had air leaks that needed attention prior to running them.

Here's a quick "how to" I wrote up a while back... http://pwctoday.com/f64/how-pressure-test-your-engine-166854.html

 

[sxi4evr]

hmmm...i should prob. do that. i dont see where it could be leaking though, new crank seals, cases sealed with plenty of yamabond, last year, and all new gaskets on the top.

 

[Waternut]

I've had leaks start at everyone of those things... I've had leaks come from brand new gaskets even so I always install gaskets with that permatex copper spray now.

Never under estimate a kawi... They will find a way to fail. I pulled my 750 engine around 10 times last summer for various issues.