350skabarat

Looks like you on limits hey? What you going for? Aggressive drag? What's you exhaust and transfers at? Looks good!

I have a degree wheel and yes they do work nicely, but remember you basically judge when you think the port cracks open? So IMHO I think measuring port roof height to the top of cylinder minus your deck height is much more accurate. But a degree wheel is just as acurate if done correctly. What I ended up doing was using both methods and then got a mean between the two.... Does any1 no what a good blowdown value for bottom end power? I reworked my ports abit and this is where I'm at: Exhaust: 184.2 Transfers: 120.1 Boost: 105.5 Blowdown: 32 What do you guys think? I must also add that I increased my exhaust ports "time area" not only by making it a tad higher but also by widening it by 1.2mm on each side. So I need some help here guys? I wana go for good low end power so I'm not sure if I should make my transfers duration longer to lower my blowdown or increase my transfers "time area" by making them abit wider but not higher. I also wana ask, what's best for a broad powerband; boost opening before transfers or transfers opening before boost. Stock cylinders the boost opens after the transfers. So ya any help would be much appreciated. Thanx

I will definitely give a full review when I'm done. Need a new crank, pistons and rebore so its gana be a while from now so ya.

Sorry I just copied this thread from our south african 2stroke forum so the projection method I was talking about was a method of calculating port timing but I kept getting wrong figures cause I was not taking crank stroke and conrod length into consideration.

Ok I've found out why my projection method didn't work. You need to take crank stroke and conrod length into consideration. I did this and it worked out, my exhaust opens at 89 and closes at 89 before tdc. The reason why I think its not 90 is because I only put two barrel bolts on and never torqued it down properly. If I had I think my deck height at tdc wouldve been less than 0.8mm. Anyways what I did was widen my port from 43 to a little over 45mm. Widened it 1.1 ±0.2mm on each side. Its sitting at 67.5 percent of my 66.25 bore. So its not on the limit but its my first real port job so I'm taking things slow. What I did was take masking tape and paste it in and measure and move it till it was right as you can see. And here is the end result I then calculated if I raise my exhaust by O.3mm I'd add just about a degree on opening and closing so the duration should be on 182 now. I don't wana go more cause I want all the bottom end I can get! I'm also running pc's and I've read they good for a low mid port. I used a dremel extension with a thick carbide tip tip for the sides of the exhaust and then I use a hand swiss number 4 file for the roof. It took me two days like morning till night to do just this! It wasn't that bad to widen the port but to blend it in so its strait!!!! Oh my sac!! Lots and lots of work! Next thing I did was cleanup some casting floors deep inside the transfers, don't have a pick of it. I also sharpened the intakes of the transfers. Next think on the list was the casting of the bottom of the cylinder. If you put your barrels on and flip the case and look by the transfer intakes you can see that this is a restriction no doubt about it! So what I did was put my piston in the barrel and put it at bdc. Checked where the piston is at bdc and marked it. Then I fliped the cylinder and checked if the piston comes past this casting. If it did I wasn't going to grind it but lucky lucky it doesn't come past it. So I measured 2mm and scribed a line. I couldve gone more but baby steps hey baby steps. Lol. Here are the pics I'm sure you can see what a restriction this piece of the cylinder has. By just looking at it. The pic above is after I grinded 2mm off and matched the cases to the barrels. Now I still wana do my transfers as I want a nice wide powerband with more bottom power, I just need a 90 degree piece for my dremel then I'm set. I'd also like some input on this aswell? I have some figures in mind but I'd like to hear what you guys think first? Also what's your comments on stagered transfers with 1degree differences? Oh I almost forgot, best pic of all Lol I know I messed the zero up abit but its not bad

Hey man, see you need those cushions, I don't have but wanted to ask if you know how to check if you need new ones without taking that plate off? is there supose2 be rotational play? I can turn myn with my hands. It takes abit of force though

What exactly is a spark arrestor?

Does not look like it? Take the caps off and measure it all up? See if its even possible for the slide to move all the way up.

Yes but what about that pin that prvents the bearing from turning in the casing?

Do those bearings have a number on them? Wana see if I can get them here in south africa?

Thanx man. Do you maybe have numbers or sizes for the needle bearings aswell?

I'm from south africa and I'd much rather get sizes and get the bearings from my local bearing shop to avoid getting smoked by some asshole. Thanx though. You don't maybe have the sizes?

Hey guys I have a knocking sound in my motor, I suspect that its my bigend or wrispin bearings. Was wondering if someone knew the sizes of the bearings? I need the inside diameter, outside diameter and width. And I also need the crank ball bearing sizes. Please I wana see if I can get these so long thanx.

His running a single carb so can't be an air leak else it will effect both cylinders, check your coil plug wires? That could be the problem, maybe the one side is not firing properly all the time, could be reedvalves? Maybe the one cylinder got damages somehow and has a different psi pressure to the other one. Strange problem actually

The cover does support that shaft abit. If you notch it I'm guessing your case will wear out faster. Don't be lazy dude?

Shot will do so. Ill just get a nice neat spacer machined. Just worried its gana make it weaker? Like maybe the bolts will strip easier if I land a hard jump

Shot will do so. Ill just get a nice neat spacer machined. Just worried its gana make it weaker? Like maybe the bolts will strip easier if I land a hard jump

That would be abit of a problem with the right peg as that plate is bent

That would be abit of a problem with the right peg as that plate is bent

Ya I wish it was that easy but I'm fro$ south africa so ill have to pay customs and all sorts of shit and wait weeks! And do you think I can buy -2 pegs in south africa! Pfffft! Forget about it! So ya I'll just make my own. I was thinking of having 2 1Omm plates plasma cut in a sort of triangle shape then ill just drill two holes and cut and weld the foot piece off on the new plate. But I'm still getting idea's. The only problem is that the right foot peg is not strait. It has that spacer welded on the frame, not sure what to do there.

Have you not shortened your shifter? Thanx for the pics by the way. How does the bike feel with the pegs more back? Do you prefer it to the stockers?

Looking for pics of -2 foot pegs. Wana make my own but just wana get some idea's

Thanx dude!

Hey guys can someone please help me with this measurment on a bone stock shee? im trying to figure out if my a-arms are +1 or not.

Is that tig welded? the welding is gorgeous!!!!!