YamaSaki YFSex-250 build

88' blaster said:
how did you do the shifter. if it is like my ex500 at least it is like a shaft to the shifter
Click to expand...
used the stock shifter... no linkage or anything like that.

Did get a chance to beat it up a bit and it took it all and asked for more. Jumps, uneven terrain, corners, ect and no problems at all. Plan to beat on it a few more times before the dune trip this weekend to make sure.

Should have more vids later today or tomorrow. Gonna try and find some sprockets locally to gear it down a little. All the gears are really long on it so I had the fiance ride it and she gave me the green light on gearing. Banshee sprockets should fit this right? No one locally carries anything be oem gearing for the blaster but a couple places have banshee stuff in different sizes and I don't think I can get anything through the mail quick enough for our trip.

- J
 
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Ahhhhh, finally, my interwebz is back up... been down for 3 days and using the phone is aweful for this stuff...

I did a few more adjustments and hacks and welds and this and that and I finally have a quad that is ready for its first REAL "test" ride in the dunes this weekend. LOTS of video from that coming shortly there after.

All in all, Got the motor in, got it running after messing with wiring for weeks, got it all tuned, finished the exhaust (Although im using my single exhaust for now cuz my sparkys havent arrived for my duals), reinforced the frame, mounted the radiator, added lights and such, handlebar controls, modified gas tank, added battery, almost blew up battery, repaired charging circuit, cut off my other fender (that was a fun day when the first one went), mounted up all my plastics.

Not bad for a months work... would have been done 2 weeks ago if it werent for that STUPID resistor in the Kawi ignition switch that i cahsed around for 2 weeks.

I will be making many more adjustments and changes and things so Im not closing this one out just yet and would like to keep it rolling until im totally finished with everything including paint.

Here she is as she sits right now.......


- Justin
 
justin.naekel said:
Banshee sprockets should fit this right? No one locally carries anything be oem gearing for the blaster but a couple places have banshee stuff in different sizes and I don't think I can get anything through the mail quick enough for our trip.
- J
Click to expand...

Yes, Blaster, Warrior, Banshee rear sprockets are all the same. A lot of dirt bike sprockets fit too.

To see a full Cross-Ref of ALL the Yamaha products that use the same style sprocket:

Go to JT Sprockets: Buyers's Guide
Enter in: JTR853



I'm running a 50T on mine. I think anything above or 45 will bump into the stock skidplate and/or rear chain guide. You can see what I had to do for my 50T here: http://www.blasterforum.com/engine-mods-swaps-129/xj550-blaster-29934/index18.html
 
79xs said:
Yes, Blaster, Warrior, Banshee rear sprockets are all the same. A lot of dirt bike sprockets fit too.

To see a full Cross-Ref of ALL the Yamaha products that use the same style sprocket:

Go to JT Sprockets: Buyers's Guide
Enter in: JTR853



I'm running a 50T on mine. I think anything above or 45 will bump into the stock skidplate and/or rear chain guide. You can see what I had to do for my 50T here: http://www.blasterforum.com/engine-mods-swaps-129/xj550-blaster-29934/index18.html
Click to expand...

I have the stock 40 on mine, I found a place locally that has the JT sprockets but i think I will pass for now. It has plenty of get-up-and-go... more than stock so not too worried but gearing it would make it a lot more user friendly.

I will be reporting tomorrow evening when I get to the dunes to let you know. usually I have a ride or 2 in even before setting up camp. lol.

- Justin
 
justin.naekel said:
I have the stock 40 on mine, I found a place locally that has the JT sprockets but i think I will pass for now. It has plenty of get-up-and-go... more than stock so not too worried but gearing it would make it a lot more user friendly.

I will be reporting tomorrow evening when I get to the dunes to let you know. usually I have a ride or 2 in even before setting up camp. lol.

- Justin
Click to expand...

I would gather up your rear tire size, sprocket sizes,gear ratios, max rpm, and plot it all into gearing commander. Knowing what your current top speed is for each set of sprockets can help you get a feel for how much room you have to play with.

Gearing Commander: Motorcycle Speed, RPM, Chain & Sprockets Calculator
 
Updates:

Got back from the camping trip yesterday and have some news to report. First, The good news. The frame and fabrication work help up great. No issues what so ever on the chassis. All the welds held up and no noticeable flexing or bending. The cooling system seems to have done its job well and didnt have any overheating issues as all. Had a slight hiccup on the charging system and after 2 hours of going through it all discovered that I had not plugged in one of the stator wires to the regulator/rectifier. Fixed that and all is well.

The mediocre news, It ran pretty good but definately needs some tuning and DEFINATELY needs gearing. It pulled strong if you could keep the revs up but wasnt much down low. The gears were just way to long for it. This should be a relatively simple fix. Also I discovered that there is a little slop in my upper steering shaft holder. This doesnt really affect the bike at all but it is noticeable and kind of annoying. This wasnt like this before so this must have happened when I crashed it a while back.

now the bad. Because I was in so much of a rush to get this thing up and running, I neglected my responsibilities a bit. When i got the motor i made a rookie move and actually trusted the a-hole that sold it to me that it was in good mechanical condition. Well, for what its worth, it seemed to be. seemed to run ok and I figured needed tuning... What I didnt find out until learning the hard way, is that one bolt was MISSING from each of the Cam-shaft carriers under the valve cover.

How did you find this out you ask? Well, let me tell ya. It all started in the middle of the 2nd ride that weekend. Out riding and suddenly a series of taps/clinks (only 3 or 4 then it went away) but the bike ran fine and seemed good after that. Wasnt sure what that was so I decided to turn around and head back to camp. about 1/3 of the way back to camp, the taps/clinks started again but were much worse this time so i decided to shut it down as soon as i could. After the shut down, i went through the motor (from the outside - mind you still sitting in the middle of the dunes) and couldnt seem to find anything that looked abnormal. i hopped on the bike and tried to fire it up again and nothing. The starter clicks but no crank. thinking to myself, "This aint good", i pulled out the trusty 2-way and called for help.

After a long and shameful tow back to camp, I proceded to tear apart bike to find out what the problem was. I became worried right away when i got the carbs off and noticed mettalic flakes in the intake of cyl 1. When I looked closer, thats when I noticed that something wasnt quite right... in cyl. 2, I could look in and see the back of the valve. But, when i look a look into cyl 1, I could see most of what looked like the top of the piston... thats odd i thought. At that point, i pulled the valve cover and noticed the missing bolts and only then realized that the head of the valve is no longer attached to the stem.

F**K!!!!!!!

So, I will be tearing down the motor over the next few days and figuring out what exactly went wrong and find out what the damage is.

On the plus side I do have lots of video of it actually running and riding on the trails that I will upload as soon as I muster up the energy to unload the rest of the truck and find my cameras.

I will also take lots of CSI pictures as I go through that motor.

For what its worth, the failure was not in my fabrication (as it usually is)

- Justin
 
justin.naekel said:
Updates:

Got back from the camping trip yesterday and have some news to report. First, The good news. The frame and fabrication work help up great. No issues what so ever on the chassis. All the welds held up and no noticeable flexing or bending. The cooling system seems to have done its job well and didnt have any overheating issues as all. Had a slight hiccup on the charging system and after 2 hours of going through it all discovered that I had not plugged in one of the stator wires to the regulator/rectifier. Fixed that and all is well.

The mediocre news, It ran pretty good but definately needs some tuning and DEFINATELY needs gearing. It pulled strong if you could keep the revs up but wasnt much down low. The gears were just way to long for it. This should be a relatively simple fix. Also I discovered that there is a little slop in my upper steering shaft holder. This doesnt really affect the bike at all but it is noticeable and kind of annoying. This wasnt like this before so this must have happened when I crashed it a while back.

now the bad. Because I was in so much of a rush to get this thing up and running, I neglected my responsibilities a bit. When i got the motor i made a rookie move and actually trusted the a-hole that sold it to me that it was in good mechanical condition. Well, for what its worth, it seemed to be. seemed to run ok and I figured needed tuning... What I didnt find out until learning the hard way, is that one bolt was MISSING from each of the Cam-shaft carriers under the valve cover.

How did you find this out you ask? Well, let me tell ya. It all started in the middle of the 2nd ride that weekend. Out riding and suddenly a series of taps/clinks (only 3 or 4 then it went away) but the bike ran fine and seemed good after that. Wasnt sure what that was so I decided to turn around and head back to camp. about 1/3 of the way back to camp, the taps/clinks started again but were much worse this time so i decided to shut it down as soon as i could. After the shut down, i went through the motor (from the outside - mind you still sitting in the middle of the dunes) and couldnt seem to find anything that looked abnormal. i hopped on the bike and tried to fire it up again and nothing. The starter clicks but no crank. thinking to myself, "This aint good", i pulled out the trusty 2-way and called for help.

After a long and shameful tow back to camp, I proceded to tear apart bike to find out what the problem was. I became worried right away when i got the carbs off and noticed mettalic flakes in the intake of cyl 1. When I looked closer, thats when I noticed that something wasnt quite right... in cyl. 2, I could look in and see the back of the valve. But, when i look a look into cyl 1, I could see most of what looked like the top of the piston... thats odd i thought. At that point, i pulled the valve cover and noticed the missing bolts and only then realized that the head of the valve is no longer attached to the stem.

F**K!!!!!!!

So, I will be tearing down the motor over the next few days and figuring out what exactly went wrong and find out what the damage is.

On the plus side I do have lots of video of it actually running and riding on the trails that I will upload as soon as I muster up the energy to unload the rest of the truck and find my cameras.

I will also take lots of CSI pictures as I go through that motor.

For what its worth, the failure was not in my fabrication (as it usually is)

- Justin
Click to expand...

Nothing is easy! Good luck on the fix. Glad to see stuff on your end is doing well.
 
I bought a CBR600F2 engine off CL like that one time. At least I paid like scrap weight for it ($50 knowing the last time it ran, it came to a violent end)

I parted it out on Ebay not long after that... because the dropped valve broke the #2 piston where the wrist pin went through the piston. The whole ring land separated and the oil ring was no longer contained.

Hopefully, your valve didn't beat around the engine nearly as violently considering you shut it down at the hint of wierd noise (good move BTW).
 
sicivicdude said:
I bought a CBR600F2 engine off CL like that one time. At least I paid like scrap weight for it ($50 knowing the last time it ran, it came to a violent end)

I parted it out on Ebay not long after that... because the dropped valve broke the #2 piston where the wrist pin went through the piston. The whole ring land separated and the oil ring was no longer contained.

Hopefully, your valve didn't beat around the engine nearly as violently considering you shut it down at the hint of wierd noise (good move BTW).
Click to expand...

HAHAHA, I had an F3 engine do that to me... on the #2 as well... only that one trashed the entire engine in the sense that the piston was basically non-existant, the con-rod broke and busted up the block, crank was bent and it put me through a ditch and barbed wire fence on my side.....

this one didnt seem too bad. as soon as the sound got bad, i shut it down right away. was at idle when it happened basically as I was taking it easy on the way back to camp. My F3 motor was at 11,000 RPM while i was knee-down in a corner at 70MPH...

- Justin
 
Updates Updates Updates!!!

Finally got all moved out to Las Vegas and finally getting settled in a little bit. Still havent gotten all the way into the blown motor yet as I just havent had time but I finally got ahold of a new motor for replacement - well kinda.

I know that the head on the old motor is trash. Everything else seems to be ok but I wont know for sure until I get it apart, but my guess will be that the head, the piston and possibly the jug are trash. Im really hoping that the con-rods and bearings are good still and that nothing ended up down in the bottom end.

What I picked up yesterday (or got the wife to pick up for an early b-day gift for me) is a replacement motor that has a bad crank bearing but runs fine otherwise. I am thinking that between the 2, I should be able to build up one good motor. My blown motor has a good bottom end and a bad top end, the new motor has a bad bottom end and a good top end.

And to help on it, the guy I got the motor from is a freelance motorcycle mechanic and an avid dirt rider so I finally have a new riding buddy here in las vegas. Oh and he flys RC stuff too so I have a flying buddy too. All is working out and the gods seem to be pleased with me. lol.

now to get into the motors and get a good running one. Hope to have it done by the end of the week.

- Justin
 
did you ever figure out a gauge setup? if not look into mychron gauges or digitron. thats what we used to use on our race karts and they are pretty sweet. do you think when you get the quad geared where you want it, it will feel like it has alot more power than a blaster motor? that sucks on the motor btw, but i guess if you have the money, it will be a good opportunity to upgrade. idk what is available for that motor, but maybe high compression pistons and such?
 
myusername said:
did you ever figure out a gauge setup? if not look into mychron gauges or digitron. thats what we used to use on our race karts and they are pretty sweet. do you think when you get the quad geared where you want it, it will feel like it has alot more power than a blaster motor? that sucks on the motor btw, but i guess if you have the money, it will be a good opportunity to upgrade. idk what is available for that motor, but maybe high compression pistons and such?
Click to expand...

Uhhh, im sorry. Did u say something? I wasn't... uhhh... I was distracted.

But really tho. Not much for upgrades but a mild port match is in order. Got a new top end and some pics coming tomorrow when im not on my phone.

- justin
 
So its not THAT bad.....





That should buff right out I think.... no? Are you sure?


f**ck! I was really hoping that nothing broke through the piston, but of course it did. My luck isnt that good. So now me and the mad scientist gotta tear down the engine and replace the piston rings I fried... sorry, fast and furious moment.

I actually drained the oild and was able to find 100% of the piston peices in the oil. I would normally run this as is without splitting the case, except there are other parts of the valve stem missing and I dont know where they are. I know there is one chunk lodged into the top of the piston but without getting that out and pulling another valve for comparison, I cant be sure that it is all out.

So my diagnosis and cause thoery (Which is kind of embarassing for me because I should have not assumed that the motor was fine) is this:

1. Someone had been meddling around in the head because I noticed that the cam carrier blocks had writing on them in paintpen noting that they were from an 03 engine... the motor is supposed to be an 05.

2. there was a total of 2 bolts missing from the cam blocks. 1 on the intake side of cyl 1, and one on the exhaust side of cyl 1.

3. the valve in question had a misaligned tappet on it. This could have been post breakage though.

4. 1 exhaust valve was missing a tappet completely and thus only one exhaust valve was operating out of the 2 for cyl. 1.

5. the cam block for cyl 1 intake was tweaked badly (right where the missing bolt was). This may have also been post breakage but the heel of the cam was more than 4mm away from the tappet when the valve should be closed. This actually also could have been the cause as the lobe of the cam would smack the tappet instead of smoothly push it and then closing it. Thus, causing a bounce and spring loaded slamming shut of the valve which could easily break the head of the vlave off over time.

So, the next step is to try and peice together the vlave and see what im missing there. I might be able to get away with a simple flush of the crank case, but I wont know for sure. I am not worried about the missing hardware in the top of the head as I dont see any way it would have migrated to the case. and it didnt appear that the hardware was there from the begining.

I think I will still split the case to be sure as I would hate to put money back into this motor only to have some little metal bit that I missed come dislodged and trash my freshly built motor.

Considering this is the 3rd motor in this one quad, and I am ANAL about proper maintenance and oil changes, I would think that perhaps I am trying to push this little blaster FAR beyond its intended mechanical design limits...

Either that or y'all f**ckers here put a curse on me for tainting the yamaha gene pool with a half-breed yamasaki. if so. i hate you all and stop it.

more coming later today.

- Justin
 
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myusername said:
did you ever figure out a gauge setup? if not look into mychron gauges or digitron. thats what we used to use on our race karts and they are pretty sweet. do you think when you get the quad geared where you want it, it will feel like it has alot more power than a blaster motor? that sucks on the motor btw, but i guess if you have the money, it will be a good opportunity to upgrade. idk what is available for that motor, but maybe high compression pistons and such?
Click to expand...

I did find some gauge solutions online but Im not terribly concerned. my finances wont allow anyway. Im already WAY over budget on this and to add to it, I just got the wifey a quad of her own (250 water cooled chinese quad) that I had to basically do a full rebuild on and new bearings all around and fluids and gaskets and such. All done there so Im back onto the yamasaki again.

In terms of the gearing, it feels like it has more power now than the stock blasty motor. It should be pretty freaking insane once running right and gear properly. The issue was that the gears were a) WAY too long for the gearing, and b) I was in soft, high-drag, deep sand. runnin the thing on packed dirt or pavement it was stupid fast. But keep in mind, stock blast motor ~17hp (generously). Stock nin250 motor, ~37hp. just gotta harness it correctly.

- Justin
 
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