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Yamahardman
15th June 2014, 18:01
So i brought a 1980 yamaha ag100 for $200.
It was pretty sluggish to say the least.

Upon taking apart the top end i found the bore to be in good nick. So i took to it with a die grinder and opened the ports up somewhat.

Upon porting it, i decided it needed a better expansion chamber. So grafted an old rz250 expansion chamber onto the front third of the ags original chamber.

Unsuprisingly when started it ran lean, the little vm 25mm carb was lacking in jetting and intake, so i went to a motorcycle wreckers and purchased a tm 28mm carb for $85 and set it up, modifying the original intake boot a little and modified the throttle cable to suit.

Goes like a cut cat now. Does wheelies and all!

Only around $300 spent including bike purchase.
(And quite a few hours shagging around, haha)

Mental Trousers
15th June 2014, 18:12
So you're going Bucket racing then?

Yamahardman
15th June 2014, 18:18
Im unsure to be honest. I did it all as a cheap lesson in porting, expansion chambers and carburation. Id have to race it like a supermptorrad on account that the frame design doesnt facilitate rearsets etc, plus id probably get told to push it into a ditch and buy a fxr150, before my foot were even to come down upon its kickstarter, hahaha.

unstuck
16th June 2014, 06:48
I love my old ag 175, had many a good laugh and a few good trails too. Feel a bit sad I have neglected it so long now, just cannot bear to look at the hot pink paintjob it got.:mad:

caseye
16th June 2014, 19:30
I love my old ag 175, had many a good laugh and a few good trails too. Feel a bit sad I have neglected it so long now, just cannot bear to look at the hot pink paintjob it got.:mad:

Hot? PINK! @#$% R u raving mad? Op's sorry thats that other fella Ness.
LOL. But pink, what were you thinking?
Mates ol 100 AG got thrashed by us almost townies, nothing they couldn't climb or jump.

pete-blen
16th June 2014, 19:43
A little bit of useless info....
The last ever BSA motorbikes made ? " I use the word MADE very losely".... Were infact Yamaha AG 100 rebranded as the
BSA Bushman... and sold only in 3rd world countrys... (surprised there none in NZ....)
The BSA Tracker used the DT motor..

See told yer it was useless info....:brick:


Heres the bloody link.... scroll down.....
http://api.viglink.com/api/click?format=go&jsonp=vglnk_jsonp_14029045768046&key=07fb2a1f7863b1992bda53cccc658569&libId=0f53e307-ed87-4547-aed0-7f99e9d1e832&loc=http%3A%2F%2Fttr250.activeboard.com%2Ft5781346 9%2Fagmans-toys%2F&v=1&out=http%3A%2F%2Fwww.bridportclassicbikeclub.co.uk %2Fbsa_bushman.htm&ref=http%3A%2F%2Fttr250.activeboard.com%2Ff532937% 2Fshow-us-your-bike%2F&title=AGman%27s%20toys...%20-%20TTR250&txt=http%3A%2F%2Fwww.bridportclassicbikeclub.co.uk %2Fbsa_bushman.htm

Yamahardman
16th June 2014, 20:36
I hadnt heard of a bsa bushman untill now! So not completely useless info, haha.

An ag 175 must have a little bit more boogie than a 100 haha.

The hardest thing about my build was that the wire feed of the mig shat itself so i cracked out the arc welder and snotted it up with some 28's then did some back grinding and did some capping runs with some 7024's and it turned out mint. Was a bastard to do though haha

husaberg
16th June 2014, 20:47
In a cylimer manual I have it has the drawings for the GYT hot up 100 port maps i will scan them tomorrow.........

unstuck
17th June 2014, 06:55
Hot? PINK! @#$% R u raving mad? Op's sorry thats that other fella Ness.
LOL. But pink, what were you thinking?
Mates ol 100 AG got thrashed by us almost townies, nothing they couldn't climb or jump.

A local "gang" stole it and painted it thinking no-one would recognize it. But I heard it riding up and down the riverbank while at my folks for xmas dinner. The nice chaps pushed it all the way back through town to where they stole it from, and donated some cash and weed to help me restore it to it's cammo paint job, but have not gotten around to it. To painfull to look at.

Yamahardman
17th June 2014, 08:45
Im seriously thinking of painting mine up in early yz livery yellow with black blocks, haha

unstuck
17th June 2014, 09:30
Mine was this color when I got it. :crazy:

http://www.off-road.com/images/content/AG100-Dont-Ask-3-31-11.jpg

Paul in NZ
17th June 2014, 11:03
I hadnt heard of a bsa bushman untill now! So not completely useless info, haha.


The original Bushman was a Bantam derivative and sold into Aussie mostly. I think they were the last of the Bantams (175cc 4 speed) and were quite good apparently. They are now rather rare and highly sought after by men in anoraks wearing strange badges that look like chickens... I'd quite like one and an original D1 as well for some reason I just can't understand... oh - and a badge...

http://i386.photobucket.com/albums/oo309/tsunami-03/159739844_full_zps467ad621.jpg

They certainly were an early 'trail' bike...

Oh - heres a picture and info on the non BSA version..

http://www.bridportclassicbikeclub.co.uk/bsa_bushman.htm

Yamahardman
23rd November 2014, 07:42
305798

Aaaand here it is now.

Does wheelies and goes fast

husaberg
23rd November 2014, 17:22
So i brought a 1980 yamaha ag100 for $200.
It was pretty sluggish to say the least.

Upon taking apart the top end i found the bore to be in good nick. So i took to it with a die grinder and opened the ports up somewhat.

Upon porting it, i decided it needed a better expansion chamber. So grafted an old rz250 expansion chamber onto the front third of the ags original chamber.

Unsuprisingly when started it ran lean, the little vm 25mm carb was lacking in jetting and intake, so i went to a motorcycle wreckers and purchased a tm 28mm carb for $85 and set it up, modifying the original intake boot a little and modified the throttle cable to suit.

Goes like a cut cat now. Does wheelies and all!

Only around $300 spent including bike purchase.
(And quite a few hours shagging around, haha)


In a cylimer manual I have it has the drawings for the GYT hot up 100 port maps i will scan them tomorrow.........


305798

Aaaand here it is now.

Does wheelies and goes fast

whoops forgot.

can you not find an 125 air cooled?

Oh well if the price was right. I will have a look for a RD Yam reed Valve and reed Rubber unless you have you got any. MY RD stuff is at the old mans but i think there is only plastic ones there though you really need alloy ones as they are ment to be better.

I have a map of the Porting for the GYT kit somewhere I think. no clymer

The mx100 had a closer ratio box from memory.yes it did


DT100A MX100

1 3.18 2.83
2 2.00 1.88
3 1.37 1.37
4 1.00 1.09
5 0.80 0.96

Turns out it is a clymer hot up but i will post it anyway it is old but a start. The MX100 has a 26mm carb vs the DT100 22mm
The thing with Yamaha's is better parts from the hotter models can be fitted, but more so for the 125cc bikes.

I have posted a lot of steering head bearing sizes and fork sizes
I can't remember where? but on the ese thread I think Rob has a link on pg 1000
I think I have posted a MX special porting map that was for a MX100/DT100 (ot sure if they are the same stroke or not)I think that was on a page for either drew or white trash


http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=250368&d=1320829362

http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=250367&d=1320829362