View Full Version : The screamer motor report.

White trash
13th November 2005, 08:18
Well, massive thanks to the team at Xtreme Machines, I received my motor parts, carb, clutch and pipe on Wednesday morning. The plan being, to document the rebuild with pics and a few tips for anyone making similar modifications. Wednesday night say the unpacking and after hurling a couple of abbusive texts southwards to Wellington, I found the parts that hadn't been included. Sorry Greg:whistle:

After a trial assembly to make sure every thing fitted, and half a bottle of Jack Daniels, I had to go home coz I felt a bit sick. Weird, must have been been the rice I had for dinner.

Get a text from Aff-man on Friday at work, the 19th meeting is now this Saturday. Shit! Finish at 9pm, wicked, off to Jamies for some quick rebuilding.

The kit included a new crank and rod, I installed new main bearings as the old ones were toast. First tip: my crankcases went together better with a 0.8 mm gasket, the 0.4 mm tightened the mains too much on the crank.

New windowed piston on, the kit comes complete with gudgeon, small end bearing, 2 sets of rings, 2 copper head gaskets and 2 base gaskets. The three port barrel slides on a charm, fit the now seperate head and fire the bolts through. It takes a bit of jiggling to get the long bolts in the right position to screw in easily but be patient. A cross threaded head and barrel bolt is the last thing you want.

Once that's all tight, the new adjustable 3 shoe clutch gets tightened to the end of the crankcase and the fly wheel to the other side. Tip: Make sure the flywheel key is properly home in its keyway befoore you attempt to install the fly wheel.

I reinstalled the original reed against Gregs advice, simply because I'd planned to modify it next week and had suddenly run out of time. The plan is to remove the center bridge between the reeds, and install a one piece reed. Next, on goes the new B1 style carb. Bigger, with a nice flat slide system, you have to be really carefull to install the throttle cable and slide spring as if it doesn't sit properly, the throttle will only open half way. I'd recommend installing the cable before the carb goes on the bike so you can check the operation easily. Another tip: the fuel inlet on the B1 carb is alot smaller the Day1/2 carb, so your fuel line is now too big. Get a line reducer for a truly tidy job (unlike mine), also, the B1s have a remote fuel tap whereas the Daytonas have the tap on the carb. Get a tap. There's a shit load of jetting changes to get it spot on as the B1 also loses the slide needle. This makes correct sizing of the main jet critical and you'll have the float bowl off a few times getting it right.

We than bolted the motor into the bike getting it as true as possible in relation to the rear sproket, then on goes the most gorgeous piece of stainless expansion champer I've clapped eyes on. It's simply gorgeous and as with all the other parts, has none of the "cheapness" usually associated with chinker parts.

The bike is now assembled and ready to ride. (2am and a 15 pack of Steinlager into race day). 4 hours sleep, load the bike up, then off to the track for testing/tuning/running in. Pull the bike out, set it up on my fancy, portable work bench and whip the bowl off the carb ready to install the fattest main available and work my way back. After all the assembly so far, this was the first hurdle. The jets supplied are slightly bigger in diameter than the jet fitted to the carb. "Fuck" was heard for miles. It's not a biggy, I just need to drill out and re tap the main jet hole. The jet supplied with the B1 carb is tiny, don't use it unless you want to melt your new motor.

I fired the standard carb back on which wont flow nearly enough, especially with the hugely restrictive filter but at least I can run the bike in and not worry about it leaning out. Taking off for a practice and the clutch was set too heavy, it wanted too many revs before engaging and getting the bike rolling so rather than fiddle with it there, I refitted the standard 2 shoe clutch and moved out. First impressions were of how tight the motor was, it seemed really horrible and wasn't running too good. As the laps grew it got better and better, overtaking Aff-man was a brease, even using only half throttle. I was getting into it a bit and starting to enjoy the bike when I felt an odd burining sensation on my, ummmmmm, nuts. Glancing down I noticed quite quickly I'd lost the fuel cap and petrol was now soaking through the stretch panel (for my huge package) in the leathers and thoroughly soaking the crown jewels.

So I once again parked the bike and walked the track searching for awol part.

To summarize, the bike is great to ride, with more to come. It's torquier than before, and by no small margin. It's also smoother and once run in is going to rev like a bastard. I just need to get the B1 carb sorted and work with the clutch. Unfortunately, it puts me out of the production class and into mod production but it's definitely going to be more of a challenge to ride and a whole lot more fun. It's still no Polini or B1 but then it's still a class below these bikes so I'm pretty happy.

13th November 2005, 08:34
Sounds awesome. How much did all those extra parts cost all up?

White trash
13th November 2005, 20:22
Sounds awesome. How much did all those extra parts cost all up?

Look at www.xpmltd.co.nz All the prices are on the site.

White trash
14th November 2005, 18:31
And here's a couple of pics. One of the old motor in bits and a couple of "The Screamer" as ridden on Saturday. Still with standard carb and clutch but you can't see them bits anyway.

14th November 2005, 18:33
So I take it that you are going to complete more than one lap at the next event

14th November 2005, 18:58
what a big load of nonsense full on bs about gay we minimotos..........
can i have a ride?

the ghost rider with mini motos pretty faaaaaaaaarkin cool.... welly boys should do a minimoto ride around the hut an river bank before beers on thursday./... you to hitcher!

White trash
14th November 2005, 20:28
So I take it that you are going to complete more than one lap at the next event

With the motor less than 5 minutes old, very much running it in and less than half throttle, I went past Aff-man on Saturday like he was chained to a tree. 'Till my missing fuel cap doused me cods in petrol of course.

The Beast
9th December 2005, 15:20
So it's all run in and going good I assume Jimmy?