I'll get up to 15-20 email notifications and then I'll have to come in and delete my subscription to this thread right before I submit my post. Then, the count starts up again. Life would be a lot easier if I would just uncheck the little box that says, "subscribe to this topic and receive email notifications of replies."

 

<div class="FTQUOTE"><begin quote>Originally posted by: HACKMUNCH

HI GUYS, NEW HERE JUST WONDERING IF ANYONE HAS DONE THE TM28 ON A 230. I SEARCHED AND REALLY DID NOT COME UP WITH ANY INFO. JUST WONDERING WHAT JETTING EVERYONE IS USING.</end quote></div>

Too many of us have done the 28 on the 230. I "think" I can speak for everybody when I say we've beat our head against the wall the required number of times before we got the jetting kinda close. [img]i/expressions/face-icon-small-smile.gif[/img]

One guy that used to post around here paid extra to have Sudco tune his 28 for him,,, never did get it to run right,,, I think 50 of these 120 pages are him posting about the tm28,,,, a couple months later he sold the quad.

I think Gforce got his to run ok. He never said that much in frustration, so I assume it was running ok. But he lives at the top of the rocky mountains (7000ft).... The rest of us closer to sea level have all kinds of problems.

Me..... I'm at 700ft and it took me about a month's worth of tinkering, but I think I have a setup that will work if you really want the tm28. The main problem with that carb is the needle. The needle that comes with the carb is WAY too lean. So, THE FIRST THING YOU DO is change the needle to a 5L1. Sudco lists it in their catalog, but they don't sell it. You have to find somebody that actually sells the needle. Once you get the needle you have to go way bigger on the main jet too. Then, once you do all that you'll find it will be running rich on the idle so you'll have to find a #10 or #12.5 pilot jet. No shop will stock them, so you'll have to order them as well. They are the leanest pilots made for that carb.

So, in summary, a 5L1 needle, a fist full of bigger main jets, and a 10 and 12.5 pilot. That should be good with a KN filter, no airbox lid, and an altitude anywhere less than 3000ft. The mountains around here top out at 3000ft and I ride there all the time.

Good luck and be sure to pad all the walls in your shop before attempting to jet this carb. [img]i/expressions/face-icon-small-happy.gif[/img]

Btw, there was a guy that posted a few times here that said he used a 32mm roundslide and he did little more than just take it out of the box. He said he upped the main jet and it ran great. I don't know,,, up until that post, I was thinking the 28 was a big carb for a stock 230 and that was the reason everyone was having trouble. The carb was just too big. But since the guy with the 32 got his running so well and with so little effort, I'm curious now. After all, the stock intake valve size for the 230 is 32mm. Hmmm....

 

WELL THANKS AND BOY I GUESSED RIGHT. I HAVE BEEN PLAYING WITH THE PWK 28 FOR A WHILE AND RELISED WHAT WAS GOING ON. IT SEEMS YOU EITHER HAVE TO RUN THEM WAY RICH ON THE BOTTOM AND LEAN ON TOP TO GET RID OF THE LEAN WOT BOG OR GO LEAN ON THE BOTTOM AND RICH AS HELL UP TOP. A GUY I KNOW SAID THE REASON WE ARE HAVING THESE PROBLEMS IS BECAUSE OF THE SLIDE CUTAWAY. EITHER WAY YOU RUN THE CARB YOU ARE GIVING UP PERFORMANCE. THIS IS WHAT I WAS TOLD TO GET WHICH IS REAL CLOSE TO WHAT YOUR SAYING. 15 PILOT, 5L1 NEEDLE AND 220 MAIN. I LIVE NEAR CARB PARTS WAREHOUSE IN CLEVELAND. I PICKED UP THE 5L1 NEEDLE AND A 15 PILOT, HE SAID IT WAS THE RICHEST NEEDLE AND MOST GUYS RUN IT USE METHONAL. I HAVE A BUNCH OF MAINS SO I WILL LET YOU GUYS KNOW HOW IT TURNS OUT. THANKS AGAIN. ALSO WHAT CAMS ARE MOST OF YOU GUYS RUNNING? MEGACYCLE OR WEBCAMS AND WHAT GRIND, I AM GOING TO MX RACE MINE.

 

ITs not the slide cutaway. That only affects the first little bit of throttle. I tried cutting mine a little bigger a long time ago and it didnt make any difference.

Is there any way I could order a 5L1 needle from that warehouse? Are you in cleveland OH or TN? The last thing I actually done to my carb was put the needle in a high speed drill and run sandpaper on the end of it to make the needle sharper than a 5L1. I had good results, then I tore the engine down for a big bore kit and that's still where I am.

If I remember right, the 15 pilot comes with the tm28. I've tried the 17.5 pilot with no luck. I use a 10 now.

Most of the guys here are running webcams stage 2. The jury is still out in my book whether thats a good idea or not. I talked to one guy that was running a megacycle stage 1, but I didn't get to talk to him long. Vince from http://vincescycle.tripod.com/newparts/lt230s.html always uses megacycle. I have a simulation program that does not like webcams (2 programs actually). It consistently gives lower HP numbers than stock for webcams. However, it says a good 1-2 HP consistent gain using megacycle stage 1. Stage 2 megacycle is also a HP loss. What does all that mean???? I have no idea. Either webcams suck or my software sucks. Somebody needs to be a guinee pig and try a stock cam and then try a webcam and see which one is better (while also not changing ANYTHING else). Till then, we'll never know for sure.

Everybody that runs a webcam stage 2 say the quad has more power though. But I dont think anyone has just done the cam without also boring it or doing something else to the engine. If nothing else, webcams requires you to use different valve springs and I have long wondered if the springs give a power boost, even though the cam grind may not be the best. Now I'm wondering if maybe a spring kit with a stock cam wouldn't be all that bad of an idea. But, like I said before, we'll never know for sure until someone runs a stage 2 and then takes the cover back off and pops the stock cam back in and runs it for a while and gives a report.

 

<div class="FTQUOTE"><begin quote>Originally posted by: HACKMUNCH

WELL THANKS AND BOY I GUESSED RIGHT. I HAVE BEEN PLAYING WITH THE PWK 28 FOR A WHILE AND RELISED WHAT WAS GOING ON. IT SEEMS YOU EITHER HAVE TO RUN THEM WAY RICH ON THE BOTTOM AND LEAN ON TOP TO GET RID OF THE LEAN WOT BOG OR GO LEAN ON THE BOTTOM AND RICH AS HELL UP TOP. A GUY I KNOW SAID THE REASON WE ARE HAVING THESE PROBLEMS IS BECAUSE OF THE SLIDE CUTAWAY. EITHER WAY YOU RUN THE CARB YOU ARE GIVING UP PERFORMANCE. THIS IS WHAT I WAS TOLD TO GET WHICH IS REAL CLOSE TO WHAT YOUR SAYING. 15 PILOT, 5L1 NEEDLE AND 220 MAIN. I LIVE NEAR CARB PARTS WAREHOUSE IN CLEVELAND. I PICKED UP THE 5L1 NEEDLE AND A 15 PILOT, HE SAID IT WAS THE RICHEST NEEDLE AND MOST GUYS RUN IT USE METHONAL. I HAVE A BUNCH OF MAINS SO I WILL LET YOU GUYS KNOW HOW IT TURNS OUT. THANKS AGAIN. ALSO WHAT CAMS ARE MOST OF YOU GUYS RUNNING? MEGACYCLE OR WEBCAMS AND WHAT GRIND, I AM GOING TO MX RACE MINE.</end quote></div>

Do they have an "old quad" series for MX? Or just trying to get in cheap? What bikes would you be running against?

Welcome to our lil home away from home, BTW!

 

Ok well i am running the megacycle 330x2 cam for the klx125 (same as lt230 cams) and it seems to be a good all around cam but i am more than likely going to go with the high lift 393-00 lt230 megacycle cam. the reason why the larger lift cams might not be making more hp is because of low compression and low velocity in the intake track. your only gonna get so much cfms through the 28mm intake track of the lt230 head. i would think with the higher lift cams, porting must be done and larger carb would have to be used to get the larger lift cams to work. the place i got the needle from is carbparts.com and yes they are in cleveland ohio. anyone have any hp #s out of the 230 engine stock and then a fully modded one?

 

i actually have this engine in a mx bike.

 

Really? Did you keep the reverse?

 

ok, calculation of forces,,, as promised: I found online that the cylinder pressures can reach as high as 600psi for gas engines. The area of a 70mm piston is just about 6in^2. So, that's 3600lbs downward on the piston. If I'm remember my statics classes correctly, all I have to do is make a right triangle with one of the angles 17.4846 and another right triangle with one angle 16.8606. And then 3600 x tan(17.4846) = 1134 and 3600 x tan(16.8606) = 1091. For a difference of 43lbs against the cylinder wall by using a +4 rod. That's a 3.8% savings. And I guess the frictional savings would be about the same too, but I'm not a statics and dynamics whiz, so I can't say anything for certain except the cylinder and piston will last longer and there will be less friction using a +4 rod.

 

<div class="FTQUOTE"><begin quote>Originally posted by: PoolGod230

Really? Did you keep the reverse?</end quote></div> see the klx 125 uses basicly the same set up as the lt230 but no reverse, it is a dr200 bottom end, and the head on the klx125 is very similar to the lt230 also. uses same valves,cams exc.