What a royal kick in the ass T350

[dyrberg123]

Hi Guys,

Just wanted to share this with you, as many of you have either helped with concrete solutions, or suggestions. I got the T350 giant make over done tonight, so i was thinkig that i wanted to start it tomorrow... But then hey, why not try to kick the thing, 3rd kick and it started, chrisp and loun popping sound - WOW. I warmed it up, and took the chocke off and it instantly settled on 1200 rpm, and good throttle respond. Only smaal noticeable thing is some low noice from the barrels, but remember they are still on std bore, only thing i did was a LIGHT hone and new pistons and rings - all NOS. I have desided if the tune went well i would rebore it during the Winter. Then i went in the house as it was 1030 in the evening here, smiling all over. Sat Down in the sofa, and thought it all over a Little, the it came to me, why the heck didn't i try it? Last time i adjusted the ignition, last year before this tune, i remembered it as i left it a bit retarded compared to factory spec, so i couldn't be all wrong.

I took a desition, helmet on and went for a drive.

Well here is the verdict.

The midrange is a littlebit weaker that before, but pretty intact, so from 3 - 5000 revs very comfy, no issues. Even WOT at 3,5k is working. And after 35 km up and Down in speed i tried to give a Little more without over doing it, remember Again it is old barrels ofcourse with new pistons but i don't have to give it as many miles as new bore demands.
KABOOM from app 6k and up (i stopped at 8k but there was alot left) it really went off, and totally changed the charateristics and the exhaust note / sound. I have had many RD350 aircoolers but this T350 feels more powerfull now. Maybe it is, or maybe it is the bigger difference between midrange and the take off that makes me feel so.

I still have some fine tuning to do, but the jetting still seems great, and the ignition isn't bad at all, so more test riding to come

Just a short refreshment on the data:

Barrels have been shaved at bottom to clean surface.

Baseplate have been added.

Barrels have been shaved at top to get the deck height back.

Exhaust have widened.

Intake the same and lowered 2mm + baseplate.

Bottom of exhaust + transfers have been lowered so they fit the piston at BDC after the baseplate have been fitted.

Kawa H1heads habe beed cut with squish to fit T350. 50/50% area. 1,1mm gab, 140 psi.

Keihin PWK 28 carbs

Y-boot KN

RD400 modified DG chambers with modded stingers 160mm Id 22mm, and new HVC mufflers

DYNA Harley ignition.

KONI shocks rear.

Honda valve springs in front forks as preload, still playing with oil type.. (any suggestions?)

So Thanks Guys, TZ, Ja-moo, and Vintageman

[tz375]

Congrats on all that hard work paying off.

That was a lot of work to come up with a package that would work. Many hours at my end and way more at your end. Enjoy it.

[dyrberg123]

Congrats on all that hard work paying off.

That was a lot of work to come up with a package that would work. Many hours at my end and way more at your end. Enjoy it.

Thanks TZ, i am so amazed that it was possible to predict that way you did.

Since it pulls so well with no hassels, ho do i assure it doesn't run lean somewhere in the spectre without me noticing?

[tz375]

You check plugs and maybe pull the heads off to check for piston wash.

You could hook up an EGT or CHT gauge to keep an eye on things or run it on a dyno with gas analysis. They are more accurate than an O2 sensor

[dyrberg123]

I think i will play it a Little, maybe get an etg to see where i roughly are, and then have it dyno tested NeXT spring after the rebore..

During may long test trip today i came up with two issues, one that has to do with the tuning and one that doesn't.

If any one could help me i would appreciate it. I have my own clues but some additional info would be great.

1. If i ride it half hard in daytime trafic in the city, not reving above 6500 - 7000 revs but almost full throttle accelerating up and Down in the trafic, and stop for redlight, then when it settles at idle it feels almost like it is drowning / choking so i have to sort of flip the throttle to get some revs back in the engine. All of this is while stopped. But when the green light comes and i drive again it goes normally.. First time i thought i was running out of fuel..

Any answers?

2. When in neutral, i get so noise from behind the clutch cover, that dissapear immidieatly after i pull the clutch lever in, and it comes back when i release.

Thanks
Any answers?

[ja-moo]

You might try to set the idle when the engine hot, or adjust your air screws when hot.

On the Kawasaki's the rivets get loose on the clutch basket and make noises just like that. We just live with it.

[Vintageman]

These engines if they have a .001" or .002" more clearance than nominal as new (but still within limit) become noisy. My T305 is this way now (+4000 miles and couple light hones) . My T350 is very quiet and fresh bore that I verified.

I agree with Ja-moo. first verify idle OK hot. If too rich it can idle down after a bit and stall out for example.

However, you add more possible clues if truly related. If you were wide open throttle and then snapped it closed real quick you may be too rich when near WOT or where every you were at.

If when you went WOT on throttle and the engine was not ready for it (too low RPM and or with too high gear for loading) then you snapped it close suddenly well that may mean nothing other than you need CV carbs versus manual slides to manage fuel for you

A good test (written up on web tuners various places) is to run the engine with a little load give it throttle when it is ready for it and back it off fast, if it stumbles when backed off like too rich, then cleans up, the WOT circuit left it too rich.

Back it off just a little and it does not stumble bu.t pulls harder than WOT did it is a little lean WOT ). Takes practice, good road conditions but, I have had good general luck with that method.

Tz375. point about piston wash. My pistons when i pull head did seemed to have a lot of wash (clean sides little carbon in center and towards Ex, but not enough miles to prove that point.

how are the plugs looking?

The clutch noise in and out at idle is common and to some extent normal. Suz has that bulletin about shaving down the bushing to reduce clearance. I bought a new bushing and it came with washer integrated and that cleaned things up i think near completely. see this post viewtopic.php?f=2&t=9835" onclick="window.open(this.href);return false;

[dyrberg123]

Thanks Guys,

Well Ja-moo, it seems that idle is around 1200 hot so that is fine i guess. If i ride the bike gentle it has no problems when stopping, but if i ride it harder and stop fast for red light it comes down to idle setting as normal, but have difficulties picking up throttle for a while.. Like if it was drowning. But it clears out if i gentle flips the throttle like following the revs up until it clears... But i have to flip it.

Vin - thanks i will try keeping your explanations in head NeXT time. And thx for the link about axial play clutch. Now i know what to do do

BTW what is piston wash?

[tz375]

Piston wash the way that carbon is "washed" off the outer edges of the crown

There are many different images on the web


Another


and a third


If it's too rich, the carbon does not form around the edges because all the oxygen is burned off and the fuel left keeps the outer surface wet and cool. Too lean and all the fuel is burned, leaving the squish area covered in carbon. As you can see form those pictures, how much wash is the perfect amount is somewhat subjective, but is indicative.

[Vintageman]

Tz

Many sled guys talk about is piston wash... don't here much about this on bike forums.

When I pulled my T305 before Ex mod, I had nice little wash and just on the two edges by transfer, plugs were light brown (nice), Really nice per this criteria, but had many hundreds of miles on engine. When I tore my T305 down recently after Ex mod to shave head, I maybe had a 300 miles and only the center was dark... like the too rich version. Plugs were much darker too Don't think I have enough miles for piston wash to have settled. Can't imagine why it would change.... other than maybe I run WOT a lot more than I use too and was always too rich

Dyr.

Here is one other possibility. The stock carbs for T305/T350 have the extra pilot jet before the regular pilot jet. It is in series with the regular one and before it (closer to fuel supply from bowl). Tiny freaking hole in it 0.6 - 0.7 (same units as an air jet forget series # now).

I read somewhere years ago it was meant to prevent a stall when you stop quickly

Ivan ( I think that's his handle on this board too) of Ivan's Performance said it helped prevent a too rich issue if I recall. My guess was too lean but he is more experienced than me. He has a sweet T305 and has a lot of professional experience with jetting

Search his posts... he hasn't had to many since. I think he replied to one of my post. I needed one of these jets and he gave me one. I have never run without. If not I was going to use an air jet but the OD is smaller and need some way to fabricate in place (real sleazy was going to be the good blue or yellow fuel line... the small one you see used on Ski Doo carb primer or gas tank vents lines... bet it would hold just fine.

At the time I thought it was needed for something to do with carb design, but now I think about it the OEM 32mm are just normal VM carbs so maybe an engine phenomena

I hope what I said before about trying two carb position quick was clear (my writings sucks I know and always too long).
If I find the article again I post it.

[tz375]

Plugs should really be white on the tips and color only on the mixture ring after a hard plug chop.

Dyr is using flatslides, so the details may be a little different but sounds like he's a little rich.

Piston wash is less clear after a lot of miles because of the build up of carbon at all running conditions.

[dyrberg123]

Thanks Guys, i will check tomorrow when i have time to test ride again...

Vin, it would be great if you could find the article...

TZ what is the mixture ring on a plug?

[Vintageman]

Dyr,

Did a quick search did not find yet (someday i'll find it). it's like i say just make quick transitions bewteen the carb circuits (i.e. idle-slide cut-jet needle-needle jet and main) see how well the transitions are. It just one of those ride and feel methods.... but thought of this one since i was ASSuming you were snapping your throttle closed when stopping hard.

I do agree pilot circuit may simply be too rich and stall. But please verify that it is differnt if you stop slowly versus stopping fast. And, is there a quick change in throttle position involed in this scenario as well. Or the throttle was fixed at the time. If quick snap involved then the point is maybe the circuit you left passed it over to idle circuit too rich... and maybe idle on rich side as well. If no quick snap I thought of that extra pilot jet in OEM carbs (prevents sloshing of fuel in bowl making it too rich)

I just change my Gt550 to stock pilots 27.5. At one point I had 37.5s in her (another story as i tried to solve a problem). It always idled. So point here even if it idles may be too rich

I'll leave Tz to answer smoke ring. I have seen this ring on four stroke but never been able to find this ring on 2 stroke even doing plug chops carefully. 2 strokes with oil injection just have too much junk is my exuse and I look fo golden brown on average or per a specific carb circuit.

[rocc99]

dyrberg123 - congrats on a nicely running bike. Can I ask what jetting you have in place?

I too am running the D&G exhaust and I also have pod filters. I went up a half step on the main to 113 and still have the stock pilot/needle jets.

I seem to be bogging from mid range all the way to top end. I don't have a tach, but I really seem to lose power towards the top.

Any suggestions as to where to start with some jet changes? Also, any good sources for the jet purchases?

Besides that, I was just curious as to how your exhaust was working? I understand that this exhaust hooks up "dirtbike" style with the spring tension system, so a complete seal isn't likely, but I am getting a ton of oil spit out around the flanges. Here's a picture of what it looks like after a 15 minute ride:

http://i1285.photobucket.com/albums/a58 ... 86f4c7.jpg" onclick="window.open(this.href);return false;

Is this normal two stroke behavior or is something up?

Thanks for the help.

[ja-moo]

I lot of writing to go through, one thing (if it hasn't been mentioned) a too high of fuel level can slosh some fuel with hard stops, causing a rich condition.