2 Strokes Down Under

I know this has been covered befor somewhat..I am just getting parts sorted for my next project.. idea is to run air cooled cylinders on lc bottom end with rz or banshee crank..I split the motors today and the rz crank slotted into the lc cases with out issue..however they are narrower on the lc...0.5mm either side of the crank webs were the rz has 1mm.. do u think this would be an issue..heating expansion etc..widening each side isnt too much of an issue but if it doesnt need to be done..its alot of time saved..thoughts?

Ok did some more work today..even though the crank fit in the bottom half there was not enough clearance in the to half..so what I did was simply attach a flat 60 grit sanding pad to my grinder I cut it to the exact diameter of the the crank held it evenly and very neatly skimmed the sides it worked perfectly..neatly and importantly gave the clearance I needed . fitted the halves together and crank sits and spins perfectly..

Can i ask why you would put air cooled barrells on lc cases? I can only think you'll end up with less hp with air cooled over lc barrells.

Im sure thats true..so why own an air cooled when you could have an lc..why own an lc when u could buy a modern 600 for half the price with twice the power.. I have had badass motors before..mito 421, lcs, yamagamma,..worked tzr..I love the sound look and the simplicity of the air cooled motors..im not chasing big hpr anymore..Iove building bikes..I have never owned an air cooled befor..but have ridden them..im sure it will provide more than enough fun ,thats why I love 2 strokes in the first place..on the technical side the lc bottom end allows me to run the lighter bottom in the lighter mono shock lc frame..the lc motor also easily allows cdi with ease ..and now can accept a banshee 4mm crank..I think it could be a sweet lil bike..I just cant get the parts fast enough..lol

I'm on board twinrock. This build will be differn't, out of the norm and i watch with interest.
I Can see why you'de want to do it. Modern cdI on the bottom end is reason enought.
Thing i've found is an air cooled's can make good power just can't do the revs of the lc. Like you said you can build somthing faster but a good stout air cooled will be a great street bike.
good job on the home mods to the cases twinrock

Yeah dont think of it as down grading an lc think of it as up grading an air cooled..lol..yeah the street is where im at these days..gone are the weekends of long country roads and track days..I have been lovin the dt200 on the street but struggles highway speeds..and I miss the sound of a twin..its been too long..

twinrock wrote: run the lighter bottom in the lighter mono shock lc frame..

You reckon the LC frame is lighter. But there can't be much in it surely.

I was thinking of going the other way, putting an LC into an A/C frame because I can't find a reasonable tank for the LC but an A/C would give me more choice - I think.

I have never held the two at the same time..but I had a couple of rd air cooled bikes here not that long ago..I remember thinking they seemed heavier built..thicker gauge tubular steel that sort of thing..more like a dt250..as for a tank..thats is the reason I went with lc over rz frame because I would have more options for tank.I was planning on using a 10ltr ag175 tank I have..its perfect and should go on..but at this stage all here say..as I wont have the frame for a couple of weeks to match it up..very frustrating as I have most of the parts but they are spread over the country..I have to wait for them..lol

Oh..the stock air box in the lc frame would limit tank swaps..and lookin at pics on line u may be right..not much in it weight wise..but I think the lc would still be lighter..and the motor will bolt straight in..

twinrock wrote: was planning on using a 10ltr ag175 tank I have..its perfect and should go on..but at this stage all here say..as I wont have the frame for a couple of weeks to match it up..

Are you sure the AG175 fits. I thought the AG175 were all twin shocks. The issue with the LC is the wide tank tunnel caused by the wide top tube to take the monoshock shock. Only a handfull of Yammies used this arrangement, and I don't think the AG is one of them. I think the XT250 and the late modle DT250/400 might fit.

I'm pretty sure both of the following are XT250 tanks.





It hasn't been a priority but I've had an eye out for an XT tank for sometime (about 2 years) and haven't seen anything worth while (damage/rust) or priced sanely (a.k.a cheap ).

I like the line and appearance of that top tank and I think it could be blended in to good effect. I don't particularly like the rear end of the above. Minialist is nice but practicality is also nice.

Ok so I couldnt wait for the lc frame from act next month so today I did a dash to sydney and picked up a 350 aircooled chasis that was on gum tree..u may have seen it..after lookin at pics on line I agree thst the lc would just be too wide to accommodate other tank options..plus I think I like the lines of the air cooled better..altho with out the swing arm they are very similar..so with the frame I placed the ag tank on and it was too narrow..however I think I can modify it to fit..it has a shoulder that I could cut a section out of invert and reweld..as for dt250/400 I have one of those tanks too..it is to narrow also and with no shoulder could not be made to fit..I really like that second rd pic..

If using an LC, ditch the stock LC airbox Justin, just use pods. Its what I did on my LC with the 421. The beauty of the LC is that the battery box isnt part of the airbox like it is on the RZ.

twinrock wrote:Ok so I couldnt wait for the lc frame from act next month so today I did a dash to sydney and picked up a 350 aircooled chasis that was on gum tree..u may have seen it....

Yep, you beat me to it. I was going take a couple of weeks to collect it though.

I'm keen on the rear hub and brake out of it if your not going to use them on this?

Mate all im using is the frame..evrything else will go..thre is only the hub no brake tho..the rear guard and chain guard is in quite good usable nick too..

twinrock wrote:Mate all im using is the frame..evrything else will go..thre is only the hub no brake tho..the rear guard and chain guard is in quite good usable nick too..

Cool! I'll txt you tomoz.

Hubs have been a little tricky to track down. What was the bottom end like? It was pretty good value for money for what was there, but I wasn't that keen on traveling all that way for the rear hub!