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Post by ryan_ott on Oct 21, 2023 10:22:57 GMT -5
Now to see if you have better luck keeping yours in place than I’ve had lately. Well I think we figured that out, different intake.
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Post by 90GTVert on Oct 23, 2023 7:03:06 GMT -5
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Post by Lucass2T on Oct 23, 2023 7:48:02 GMT -5
I think you'll have much better luck with it now on this setup too, If I was to be a betting man I would say your carb troubles might just have ended... (let us pray) 🙏 C'mon don't jinx it dude😁 Praying won't help I am afraid. God doesn't know anything about 2t carbs, they weren't invented yet in his time. Unless he recently read Graham Bell's 2t bible or the Dellorto manual.
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Post by 90GTVert on Oct 25, 2023 7:49:28 GMT -5
Here’s the Bonneville X360 intake installed. I have the other Malossi intake for 30-34mm carbs as well, but didn’t want to try it after Ryan’s recent experiences with the carb popping out. Fits OK. Didn’t even have to mod my seat bucket for it to clear the cable. I did swap to a 90 degree adapter vs the standard straight adapter that the PWK comes with. The filter is pretty huge, but so far so good. I fired it up for the first time yesterday. Idled and revved well enough with a quick adjustment that I took it down the road to see how it runs. It seemed to run well cruising down back roads and EGT looked good. Didn’t sputter as much as I’m used to at low throttle. I stopped to try a quick acceleration test but EGT hit 1402 by 60MPH so I let off. Tried again and I let off in the upper 1300s. Idle hangs and richening the mix screw makes it not want to idle so it prob needs a needle adjustment. I think I’m gonna start with a bigger main jet first because it’s way hot and I’ll see how much that changes low throttle. I’m glad Ryan had posted his tune, because the 122 MJ that it came with would have been light years off.
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Post by zekefab on Oct 25, 2023 11:32:25 GMT -5
Iv been following your progress with carb tuning. I have the same engine in my bug eye with maybe 200 miles on it. Thought my jetting was good as I’d hit 80mph on the freeway but then I stalled a Koso egt as I learned more . sadly it lost compression going up hill 3/4 throttle and egt was 13,5🫣. Havnt pulled it apart yet but bought a spare piston/ring. probably should have measured the jug first to see what piston I actually need . interested in your results with this carb. 🤘🏼🤘🏼🤘🏼
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Post by 90GTVert on Oct 25, 2023 16:27:35 GMT -5
So far not so good with tuning. Moved up to a 195 MJ. Still too hot. Moved up to 205. Still too hot in 1/8 mile runs. That’s the largest jet that I have and that is found in Stage6 and Polini kits… at least what’s on ScooterTuning.
I moved the needle up to see if that did anything at all to WOT since it seems to need more fuel down low anyway. Plug is fouling and I couldn’t do a run, but it still got hot if I held it WOT.
The S6 filter is not oiled and I just left it that way. I guess I’m gonna oil it and see if that changes jetting after talking to Ryan about it. I don’t recall seeing a big swing from oiling, but foam should generally be oiled for better filtration so I’d expect it could make some change. Nothing to lose by trying at this point.
If that doesn’t work, then I either need to buy a bunch of bigger jets or try the UNI that Ryan uses instead of the S6 with the bell mouth adapter and see if jetting changes.
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Post by oldgeek on Oct 25, 2023 17:58:40 GMT -5
Good thing you have a pony keg for a gas tank, with outrageous jetting like that you will need it!
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Post by zekefab on Oct 25, 2023 18:17:10 GMT -5
Yes oiling makes a difference. In past I have also used a sock over the filter. You can pull it half way off to fine tune more or less enriching and judge where to go with jetting from that
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Post by 90GTVert on Oct 25, 2023 18:19:45 GMT -5
Good thing you have a pony keg for a gas tank, with outrageous jetting like that you will need it! The good news is, with this gigantic carb it feels like I'm barely touching the throttle to cruise 50MPH. I replaced the spark plug and oiled the filter, so we'll see what happens tomorrow.
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Post by Lucass2T on Oct 26, 2023 1:08:49 GMT -5
Does this polini pwk takes polini jets or keihin jets. If the latter applies, you could start looking in the dirtbike scene for jets.
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Post by 90GTVert on Oct 26, 2023 7:20:51 GMT -5
Does this polini pwk takes polini jets or keihin jets. If the latter applies, you could start looking in the dirtbike scene for jets. Keihin 6mm hex jets (99101-357). I just ordered the 6 jets they have from 200-230 (overlapping just in case sizes don't match up to what I have) for basically $30 from Niche Cycle. I wanted to get something on the way to be prepared if oiling doesn't reduce the jetting requirement significantly. There's an $8 kit from amazon of generic jets to 250, but super cheap generic jets worry me a bit. amzn.to/3rYiS9P
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Post by 90GTVert on Oct 26, 2023 17:54:43 GMT -5
I fired it up this morning and let it warm up. Went to leave and it took nearly 1/8 mile to clear out and ride normal, so I thought it must be really rich at idle. I stopped to do an acceleration test and RPM was hanging and not returning to idle for quite a bit, like it's too lean. It did that every stop after. I always record EGT at 60MPH in my 1/8 mile data, so here's a rundown of how everything has gone so far. 185 MJ : 1391F 195 MJ : 1374F 205 MJ : 1345F 205 MJ, Needle Raised 1 Notch, Air Filter Oiled : 1288F 2 changes at once in the last one, but I think it's mostly from oiling the filter because it was hot WOT with the fouled plug when I tried the same setup minus filter oil the day prior. Keep in mind that it goes mid 60s in the 1/8 so it gets hotter than those numbers. Most of my best runs with previous setups tend to be between 1190-1225F EGT at 60MPH. Just to throw a wrench in the works; my EGT started to randomly quit working right before this. I replaced the sensor with the carb. I should have done one more set of runs with the old sensor or used the new sensor on the 28mm carb at least one round. It is the exact same sensor though and had similar resistance readings to the replacement. If I had jets to go richer, then I could get an idea if it's right by watching the times to see if they improve as EGT approaches past results. Well... if I wasn't getting belt slip. Now the belt is slipping more and more. So I was hoping the CVT would hold up and work for a full round of carb tuning, but it's slipping quite a bit now. That throws off times and RPM data that could normally be used to see if it's wanting to pull higher with different jets. When I did test runs right before the carb swap it was 13,650 at 60MPH in accel runs (avg). It's now worked it's way up to just shy of 14,000RPM at 60. Where it's really noticeable riding is taking off. It just feels like it takes a bit for it to really grab. My 60fts are in the 2.50s avg where they are usually 2.30s or even 2.20s averages. I've got almost 1,300 miles on the belt, but I also upped the spacing not long ago so I'm assuming I'll either need to replace the belt or drop the spacing. One glimmer of hope is that I have seen it do some good 0-60s while going slow at lower speeds, so it makes me think the carb does have potential to offer some improvement. Could just be a fluke or it liked running leaner than is safe for actual riding though. I was looking over this guide, because the circuits in different carbs act in different ways or have more influence in different areas. I often link the pilot jet more directly with the idle mix screw and generally if it will idle well then I'm OK with the pilot, but I think I may need to move up on that as well as their guide points to that having a lot of influence off idle up to maybe 1/4 throttle. Possibly a larger pilot and leaner mix screw setting would help? Or maybe it's needle straight diameter? I'll get there eventually. www.keihin-na.com/assets/1/7/slide_valve.pdf
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Post by 90GTVert on Oct 27, 2023 8:02:42 GMT -5
I’ve got the CVT apart, so here’s some fun stuff. 1300 mile drive belt is about 18.95-19.15mm, depending where I measure. One new belt is about 19.25mm. Another new belt, same thing, is around 19.4mm. New spec is 19.5mm. I’ll prob clean up the old belt and take some shims out. See if I can get a little more out of it. Gonna sand the vari faces at least to try for a little grip. When I took the variator off it was sticking a little. Opened it up and the steel o-ring is pinched. Can’t push the boss back through it, and shouldn’t anyway. No spare so I found a high temp o-ring and I guess I’ll find out if that’s a bad idea. I’ll be trying to get some replacements though.
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Post by jackrides on Oct 27, 2023 12:14:32 GMT -5
If you have a couple extra jets, you can always try the old way of finding the largest micro drill bit that will drop thru your #205 and use the next larger size drill bit to enlarge an extra jet. A pin vise would do it unless you want to spend time centering the jet (with the drop thru method) in a 1st class drill press.
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Post by 90GTVert on Oct 27, 2023 12:26:06 GMT -5
If you have a couple extra jets, you can always try the old way of finding the largest micro drill bit that will drop thru your #205 and use the next larger size drill bit to enlarge an extra jet. A pin vise would do it unless you want to spend time centering the jet (with the drop thru method) in a 1st class drill press. I had that thought, but buying jets is just as easy as buying drill bits and saves time and effort. Figured I’d just work on the CVT and maybe low/part throttle a little. Just got done setting the mix screw to 3.25 turns out for best idle speed. Actually 3.5 was best but err for safety…. especially with today hitting 80+ and weather back in the 50s and 60s for highs next week. Normally if an air controlling screw is 3.5 TO for best results, I’m figuring it prob should have a smaller pilot jet…. but it hangs like it’s too lean even with how it was with the screw 1-2 TO. Keihin says the pilot jet is most effective off idle to 1/4 with the needle straight diameter doing it’s thing most from 1/8 to 1/4. I’m gonna switch the JJL to JJK and see what happens. That will drop straight diameter 0.01mm. If that doesn’t work, then I guess I’ll pop in a 55 or 58 pilot. 🤷♂️
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