81 SR250 tracker build help

merc4now

Been Around the Block
{I was asked to move this from 1-800-help to here}

Ok I've posted before and honestly went no where with it (gpz and kzltd). Was made offers on the projects I had and needed to apply the cash to keep my aging vehicles running for family. I do work on the side anything mechanical and electronics/computers for side cash or trades, this came to me via small cash plus trade (two seperate ones). I figure start small to learn the basics and move onto to bigger bikes in years to come. After picking these up I looked for cafe style SR250's and some where pretty cool but for some reason the tracker/brat? style kind of stuck with me when researching what I wanted to do with this. So short and sweet I could use all the help possible to make this 1981 yamaha Sr250

look as close as possible (maybe diff paint but honestly Id be happy to completly clone it) to this

http://www.pipeburn.com/home/2012/6/17/crds-95-yamaha-sr-250-atomica.html. Now made respect goes to SteveG for his "Sr250 Named Mexico" and i'm gonna read over his tread a few times to see how he started and his tweaks as its the closest I could find on this site to the "Atomica" build. But any help would be appreciated. even like simple stuff, can anyone recognize if it has the stock forks/ tire size? what are those style of handle bars called? and that seat just a flat custom seat on a custom loop?

Ofcourse for starters it doesn't run so I'm going to go through some basic checks and see what may be the issuse previous owner thinks it jumped timing. I also have another on the side in back of my garage, so i'd like to build two maybe competly different styles just to play with customizing.
 
Hi and thanks for moving the topic. It usually works this way; Members start a build thread where other members can contribute ideas or help and when you hit a serious/major problem with your build you can ask in the 0800 or other problem sections like electrical/engines/wheels-tires etc.

Because you're not really having one problem but are starting a new build its easier to start a build thread aswell.

Anyway, welcome back and good luck!
 
Ah ok I figured this section wasn't until you where atucally doing the build I'm still trying to research the parts and what needs to be done to even start. Either way what ever needs to be done just looking for some advice for complete beginner from the beginning (to customizing been riding for about two decades now). Thanks for the looking out
 
Hi merc4now,

Thanks for the mention. I also like the Atomica bike, it looks great, but you will realise when you start your own build that the Atomica boys used a few shortcuts that don't show up on their pics. Their exhaust looks like they have either painted over or bandaged the rusty parts of it, the forks have been painted instead of stripping and polishing back to aluminium, there are no indicators, legal rear light, license plate or horn, the engine casings have not been polished, the wheels have not been stripped down - they have powder coated the spokes - same goes for the rear brake plate. It's a very nice bike in the pics, but would not look quite so good in the flesh. All that said, I still think the bike looks as good as, or better than mine in the pics.
 
As for where to start. Strip the bike down totally. Get the frame, swing arm and any other small bits that you want powder coated and start from there. Powder coating is surprisingly cheap and looks great. If I were you I'd look at getting a seat loop welded on before powder coating, your frame looks to have been cut very short.
 
Dude don't cut yours short you did an impeccable job, I love it, like I said I'm reading your post again and again. I'm on the gulf coast and for some reason digging the minimalist look, maybe I miss my old jeep or maybe I'm reaching really far in my desire to own a new yamaha star bolt. I'll do inicators but just enough to be barely legal thinking led's almost hidden until turned on. I much like greenserfer have wanted a SR500 since I learned more about reserecting older bikes and then found this site. I've only seen one and it was in poor condition and about the same price greensurfer paided for his gem, which is well above my fun side project money budget.(atleast all in one dump). I actually picked up a 80's xt 550 in hopes to mimic one but I'm trying to start simpler since that would require alot of modification just to bring it down to normal street and urban riding height (not to mention my seat height being a 5'5 guy) and wheel matching ect ect. Side note I'm not sure I mentioned it I have an xt250 parts bike (piston busted so guy gave it to me as a basket case (no plastics) for $50 figured hey thats what I'd pay for the kick start gear alone, so I have what I believe is everything to make it a kicker.
 
Yeah I love the minimalist look too and my bike would look different if I didn't need it to be practical and legal for UK roads. The front mudguard would be gone for a start. Good work getting the kicker - they are not cheap. The shocks on mine are 235mm long (originals were 210mm, yours look shorter) and at 6 foot I sit easily flat footed on the bike.
 
Yeah see thats the problem the guy I rescued it from was trying to chop it, before it lost ablity to start, which it has a neat look kinda of for a backyard chopped low low budget deal, but all he really did that I can see is cut the back (shorter then I'd like) and cut everything out of the seat using just the plastic that clips into the latches and put those bars on it oh, and did I mention he put a bike magentic speedo on it? So I have to see whats even stock still or hacked stock? I'll start stripping it soon and employ my little brothers help since he so gracisouly has occupied my computer rooms couch as his living quaters for the past 6 months with what seems to be no intention of finding a better job and his own place. Reguardless look forward to all the help!!
 
It actually looks like the bottom of the tank is now level. Did the PO also replace the shocks with longer ones (IIRC the OEMs are 12.5")? I was also thinking of putting XT550 (15") shocks on to raise the tank to level.

The PO also cut off a fairly significant section of frame about 8" after the shocks that helps stiffen the frame. You should definitely have a hoop welded in.

No idea as to what style handlebars you currently have but the OEMs were 7/8" so as long as the mounts are original most any 7/8" bar that fits you and the build goal will work.

Original gauge was a single speedo/indicator light unit (no tach) with cable drive off the front wheel. OEM fork tubes were 32mm; USA wheels were 18" front, 16" rear; tires were 90/90-18 and 120/90-16 (max - 100/90-18, 130/90-16); Carb – 34mm; Spark Plug: NGK BP7ES; Sprockets: 16/46 (17/42 works better); Chain: 520x102 (103); Battery: Yuasa YB12A-A (5.3125” x 3.1875” x 6.3125”); Oil filter – Fram CH6005. All the stuff in the owner's manual (both owner's manual and shop manual should be available on-line).
 
Once I get a change to sit down and amake a list I will post it to get more feedback,

I'm definatly going to get a loop. I have a small mity mite or something bender I never used so would be a great first use and a certified welder down the street who gives me really good prices if not free for some things. Itll be done right thats why I was asking for guidance.
 
Just saw this thread. Your frame looks nearly the same as mine did when I picked it up. Just a word of advice. If you want a higher rear make sure to put a bit of a tilt up in the new rear and make it a bit longer.
Mine is flat and as you can see it is more of a "bobber" than a "tracker". Wasn't really the look I wanted but I do plan on sticking a cafe seat on once I work all the kinks out.
 
Ok well it was raining so finally got a chance to pull the bikes down and get to work, first order of business make one out the the two (three motors) I have running and rid able. First questions for those who have done these where did you get you gaskets at mainly carb is concern right now. I cleaned one and got to fire but the bowl seal is done and leaks.
 
Got my gaskets from ebay. You can get a full engine set ( http://www.ebay.co.uk/sch/i.html?_from=R40&_sacat=0&_nkw=yamaha+sr250+gasket+set&_sop=15 ) and a carb rebuild set ( http://www.ebay.co.uk/sch/i.html?_odkw=yamaha+sr250+carb+gasket&_sop=15&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.Xyamaha+sr250+carb+repair&_nkw=yamaha+sr250+carb+repair&_sacat=0 ) quite easily and cheaply.
 
Thanks Stevie G. I always worried about eBay quality but guess ill take what I can get. Oh that's why it was so easy for you toto findem there mostly UK providers. I'm in the states.
 
Most OEM Yamaha parts are still available individually (e.g., partzilla.com, powersportspro.com, even the local Yammie dealer). Have not seen a gasket set from a USA distributor but it could be out there.
 
well actually the link Steve G post the very first and cheaper one states it ships from Wisconsin, I'm having trouble finding a kit or gaskets locally for the carbs, as most cycle parts drop downs wont even include an SR250. I may just order one off ebay guess. I need to read through the previous builds and see what people upgraded the jets to since I plan on doing a pod filter.


Side not anyone know the differences between a XT250 both engine and carbs? One of the three engines I have is a xt250 the carb is completely different. I remember reading when I first pick them all up separately that the XT head was a little more open the the stock street one?
 
true true I see that now, may order that set of four gaskets alone or the set of two with needles sucks its $25 shipping though so kinda kills the savings maybe if I order a few more things it would make it worth it I'd rather gave a few on hand versus ordering each time and with three carbs 2 being street stlye I know I may drop the bowl every season.
 
From the Sirius site it looks like the SR250 carb is 1/4 of the rack from a XS1100 so you might be more successful finding gaskets for the XS1100.
 
The xt250 has a 75mm bore, the sr250 has a 73.5mm bore. But the stroke is the same. I'm not sure if its a direct swap on the barrels or not. Something I going to look into if my wife ever stops spending all my cash (unlikely :) )

Don't know about the carbs sorry.
 
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