YZ250 Blaster Build Log

[Tbrock77]

Just straight rad/heater hose might kink. So with size you need probably be looking for heater hoses.

We'll have to see what happens. Radiator hose is cheap so if it doesn't work out it isn't a huge deal.

Didn't get the yz yesterday because of the rain and the current owner not getting home until late but we're set for today so by the end of the night I'll have some pictures and some info on the bike.

My light bar is also supposed to arrive today

 

[Tbrock77]

Light bar came today can't make the mounts yet but you can see in the pics how I want to mount it. Hooked it up to a battery just to see how bright it is, it's definitely bright enough for a blaster headlight haha

 

[Herpderplol]

You said the YZ does not have a lighting coil. How do you plan to charge the battery on the go? if you plan to i suppose

 

[Tbrock77]

You said the YZ does not have a lighting coil. How do you plan to charge the battery on the go? if you plan to i suppose

I don't plan to. I'll have to charge the battery if I use the lights, no big deal.

 

[Tbrock77]

Headed home

 

[harley1-5]

for coolant hose you can use automotive heater hoses,when there is a bend a spring inserted into the hose will prevent kinks

 

[Tbrock77]

Bike runs but is only making 115 psi compression. I haven't been able to find where it should be for a 1987 but I've seen above 200 for the newer 250s. Coolant in the engine oil by the looks of it. Coffee brown oil means coolant in there right?

I think I'm going to split the cases, new crank bearings, seals, gasket and top end. I'll see if I know anyone who can true a crank, if not I'll send it off.

 

[bansheedave]

Bike runs but is only making 115 psi compression. I haven't been able to find where it should be for a 1987 but I've seen above 200 for the newer 250s. Coolant in the engine oil by the looks of it. Coffee brown oil means coolant in there right?

I think I'm going to split the cases, new crank bearings, seals, gasket and top end. I'll see if I know anyone who can true a crank, if not I'll send it off.

If your going to tear it down, split the case and go threw it, you shouldn't be worried of oil condition...lol

 

[Tbrock77]

If your going to tear it down, split the case and go threw it, you shouldn't be worried of oil condition...lol

Just wondering what coffee brown oil means

 

[Herpderplol]

Usually with coolant or water you will get some gray solids forming. But im not 100% sure

Maybe its the type of oil? black coffee? lighter like you add creamer? theres a lot of "coffee" colors IMO

 

[Tbrock77]

Usually with coolant or water you will get some gray solids forming. But im not 100% sure

Maybe its the type of oil? black coffee? lighter like you add creamer? theres a lot of "coffee" colors IMO

Definitely not just oil. It is coffee with cream haha. A very light brown, I looked around on google and it appears that it is indeed coolant in the oil.

 

[Herpderplol]

yeh the light brown would be coolant and/or water

 

[Tbrock77]

Got my shocks and my radiator today. Shocks are just like they were described, really happy to have them in hand

The radiator doesn't fit behind the Alba Bumper but does fit behind a stock bumper. I thought I might run into this problem so the options are, use a stock bumper, refab the alba bumper or machine the radiator to lose a couple heat pipes.

 

[jus_me]

Don't put the new shocks on upside down..

Nice rad,, Whats the dimensions?

 

[Tbrock77]

Don't put the new shocks on upside down..

Nice rad,, Whats the dimensions?

I didn't install those shocks, just how I bought it! Haha

It is 8 1/2 by 14? by 2?, I can't recall the second 2 but I know it's 8 1/2 tall which is causing the issue

 

[Herpderplol]

I had tried to post earlier about the bumper thing. before all the radiator talk

i was going to say i would have built a custom bumper much like the alba, but make that mesh plate on the front the same size as your rad.
then put some solid mounts on for the rad and it would be perfect

 

[Tbrock77]

I had tried to post earlier about the bumper thing. before all the radiator talk

i was going to say i would have built a custom bumper much like the alba, but make that mesh plate on the front the same size as your rad.
then put some solid mounts on for the rad and it would be perfect

I'm not sure if I have access to a pipe bender or not. My dad's friend is going to help me with the welding and fabrication of the mounts, he works for a tool manufacturing engineering firm so I will have to run it by him and see what he says. I can't make the bumper too much wider because the wheels might hit when I turn and I do really like the look of the alba bumper so I want to try to get that to work.

 

[Tbrock77]

Pulled the yz motor today, not good but could be worse. It seems they chain came off at some point and broke the case, someone epoxied it. The motor was covered in mud, oil and grease which is why I didn't see it before I bought it. Cylinder is scored terribly and I'm 99% sure the piston in there is NOT the right size, the 1/8 gap around the piston lead me to that conclusion. I haven't taken it fully apart yet and probably won't until I get new cases and everything to rebuild the motor.

 

[best]

Whoa, dude, lots money gonna be needed for that 87 motor.
Think it over, the narrow ratio transmission? work on a pipe?

I have a KTM powered Blaster.
Seriously excess power, but what a quad needs is gears. Specifically more gear range.
Look for a 6 speed wide ratio transmission behind an engine that fits.
I am (very slowly) working on a true Blaster powered Blaster because of the excellent gear ratios.

Some rad picts for you. YZ Otis was my inspiration, with his Mojave rad:

So here is mine:

Tucks up out of the way nicely:

Steve

 

[Tbrock77]

I'm looking into my options right now, the YZ is going to take a lot to rebuild. I do have a LT250R motor that's ready to go, I was trying to keep it in the yamaha family and I'm not sure how easily the lt motor would fit in the quad.

as for the radiator, I would like to mount it up front for simplicity reasons and the added airflow never hurt anyone.