Years with Yamaha SXViper

Update, cleaned carbs and fitted them to modded airbox. Added fuel lines also.
38mm cleaned.jpg

Removed that pin and welded it. Now it is same as sxviper cover.
wpump cover.jpg

And what do you guys think about modding that water rail? I want to make it fit straight to viper coolant system. I think that if i cut everything marked on red and then i weld connector straight to side. I may have to use new L-shaped cooland hose, but then i can use just one hose. Hope u understand what i mean 8)
rail mod.jpg
 

that what I thought especially after this week when I removed my air box in my viper and noticed that it was not really sealed compared to my vmax that have clamps with screws.

I thought about asking a question about that but I have my answer now!!!! will do the same when putting it back.
 
That grey stuff is just normal silicone sealant, maybe i should clean it little.

Weather started to get cold so i have to start my triple, it is pretty low when shocks out of air seasonfirststart.jpg

Made new brackets for bigbore motor, also changed rear bracket because it was broken.

engine brackets.jpg
bracket broken.jpg

Changed new cylinder and piston for hauck 780 and modded water rail. Water rail looks awful, it was really hard to weld. Especially it was my second time to try aluminium welding :D

780 rear.jpg
780front.jpg
780side.jpg

I also started to mod those ruined bigbore pipes, but i flanges won't fit stock cylinders... Have to assemble bb motor and then i can mod those pipes.

hauck800bbpipes.jpg
 
Nice mod and lots of hard work through the years, Vipers are great sleds with a lot of possible mods ! Keep the story rolling SX !
Blue
 
Hello, nothing special yet. Found old crankshaft in the box, but i can't figure out where is it from. There is text 8df, how can i measure is it 59.6 or 62mm stroke.

I was also thinking that is it possible make "big" triple with srx or Viper crankshaft and cases and then fit SxR 700 70.5mm cylinders to cases with right spacer like hauck 800bb kit?

I was also thinking that what is difference with viper ja srx hauck 780 kit. Found those cdi timing curves and makes me think that is there something other things what i should know. I don't want to burn that engine immediately��

Timing numbers what i found on forum:

SRX 700

7750rpm - 18 degrees
8000 - 13.5
8500 - 9
9000 - 4

Stock Viper

7750 - 24 degrees
8000 - 18
8500 - 18
9000 - 13
9250 - 11

Pic of Crank:

IMG_20181223_204801__01.jpg

Something offtopic:

My hometown local motorcycle racing, i have riden over +170km/h on main straight with viper. Snowmobilerail goes near railway track and it is not straight or that long, nowaday i would scare a lot to drive that fast��

Here is some link, check it!
https://youtu.be/FnAPQcKKT5I
 
That box is originally from viper crank packet, so it doens't tell me anything.. That 8DF number is all i know, but If anyone knows how to check stroke lenght, some measurements or something let me know.
 
I believe 8DF prefix usually refers to a SRX 600.

SRX 700 = 8DN
SRX 600 = 8DF
Viper = 8EK
700 SX = 8CH
 
Last edited:
Yes, 98-99 SRX bottom ends are the same.
I think just the bore changes.

Things goes pretty hard to understand, but if 98-99 SRX 600 and 700 bottom ends are same? So 98-99 models use 59.6mm stroke crank, because SRX 600 is 59.6mm stroke right?? and bore is 65mm, it makes 197.99cc per cylinder, means 593,97cc?? And then 98-99 SRX 700 would make 668,58cc or does it use bigger bore on those years? 00-02 SRX use 62mm stroke crank and 69mm piston and it makes 695,52cc like viper.
 
Finally got some time to build sled. Today i put some blue heat wrap to speedwerx pipes and started to disassemble the engine. I also assembled all neccessary parts to 780 engine. Got some problems with oil pump, because it was in a box and there were no hoses.... I have to do everything, but one thing is weird thah why there is a "check valve assy", i haven't ever seen them on other engines. Engine was used on watercross racing so there were three extra holes in cases what i have to fullfill. It was a relief that thread was NPT so i found blanks on local hydraulic store. I shortened them and put some hard loctite. Some pics ofc it. Tomorrow i can start to fit pipes, and if everything goes right maybe i can make it run!

blank.jpg

motor_ready.jpg
New brakeline hose, ofc it is blue 8) I also have to clean those stock carbs and change 47.5 pilots to 50
brakeline.jpg
 
More update:

Assembled motor and fitted pipes, now those fit pretty nice. It is still tight, but i hope it will be ok. Now just a lot of welding and sanding. I notice that reverse gear mounting crew was lost so i replaced them both to new. I also notice that brakedisc knock was loose so i made a new, but it is still a little loose. I think that dics is well-worn... Need to replace atleast chaincase lover bearing, it is really bad. One thing that you can see in the pic is that waterline.... Yeah, i didn't notice that SRX rail is totally different position than viper so need to mod it again... It takes a little head 8) Here is almost winter so i'm going to put old 700 back in and ride with that..
I have some plans to mod steering, but let's ride a little first before change engine again...

And pictures:

Silencersadd.jpg

pipeclearance.jpg

Some diy bushings from POM plastic, now it is nice and tight. Replaced only lower part.

diybushing.jpg

Feel free to comment what you think, if you have some nice mods to do, please tell me.
 
Finally got time to ride. I found some parts on forum member so maybe i don't have to mod that water rail, but still need to work on pipes.
Some pics of first ride of season. It is pretty nice that i didn't crash as usually 8)

Now front end works fine with swaybar, but i have to change some joints on steering or whole steering system, who knows...
first ride.jpg

Trails were pretty good, little bumbs, but there is still a lot of dikes. If you can't ride fast enough and "jump" over it, it feel like crashing and then you are going to "space". Direction of speed changes radically.

outof.jpg
This is what i mean...

first ride2.jpg

Damm it sounds so nice ride uphill with speedwerx pipes running 9000rpm. Next time i take gopro and film it.
first ride3.jpg
 
Nice! Did you have problems with the steering that you said it needs to be replaced?
 
Nice! Did you have problems with the steering that you said it needs to be replaced?

Well, steering joints are pretty loose, those "golden" ones especially. So steeringi is not so accurate as it should be. I have made a compromis with steering, so that steering arm is not "lined" with control arms so there is always bumb steering. I think i could mod rack steering like yamaha snowcross sled, then there is not so much bumb steering when i can get steering rack line between control arm level. It is hard to tell what i mean, if i mod it i'm going to put pics and show what i was thinking. I have some measurements, but i have to check what parts i'm going to use. I have little plan, but lets see. Found some pictures of yamaha offical rack steering kit in web, but i know i have to mod it by my self.
It would cost way too much to buy kit even if find some...

rack steerin1.jpg

rack steering.jpg
 


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