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Post by ryan_ott on Jul 20, 2017 5:27:46 GMT -5
Have you tried different needle settings? You can use a thin washer under the clip for a half size if the next size up or down is too much.
In all honesty to get all stages perfect is short of a miracle. If cruise and top speed operation is good I'd just try to deal with it. I think that's why the larger 4t bikes have pumper carbs, squirt a little extra fuel to makeup for the imbalance from transition.
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Post by tsimi on Jul 20, 2017 6:07:27 GMT -5
ryan_ott Yeah, you're probably right. It isn't that bad at the moment and I am sure when I get the clutch rpms a bit more up it will be lot better. I guess that's part of the 2T game. Tuning, tuning, tuning till satisfaction.
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Post by tsimi on Jul 20, 2017 18:30:27 GMT -5
ryan_ottWhat are typical symptoms of reed block going bad?
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Post by ryan_ott on Jul 20, 2017 18:49:03 GMT -5
As long as the bike starts easily and you don't get too much fuel mist back into the air box they should be ok. Really if you pull them out and you can see light where the should be sealing they may be worn. I've also had new reeds that didn't 100% seal. Do you have a lot of miles on them?
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Post by tsimi on Jul 20, 2017 19:01:52 GMT -5
I never pulled them out since I put together that MHR Rep. engine. That was around 2500 km ago. I used 2 gaskets and permatex to seal the intake and reed block and to remove, clean and re-seal it would be a pain in the ass.
There is a tiny bit fluid (oil? ) inside the airbox intake but not more than usual. Maybe it is time for a inspection and evtl. replace the glass fiber reeds with carbon fiber?
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Post by tsimi on Jul 22, 2017 7:14:27 GMT -5
So I finally got around to install a few more parts and do more adjusting. I am happy to announce that all troubles are gone! I installed the yellow Malossi torque spring and I also adjusted the carb again and ended up with 35/96 jets with the idle screw at 1.75 turns out. She pulls hard again, from bottom to top, all the way. I would say even better then with my previous setting. I am super happy now. I just need to do a slight roller weights adjustment and probably drop the main jet from 96 to 95 and it should be perfect. I also wanna say big thanks to spaz12 for recommending the Polini 2G clutch. That is THE best clutch I have used thus far. The Polini guys really did a fantastic job with that clutch. What makes her so special is the possibility to do little step adjustments to it to get the clutch to engage at the right rpms. The manual says, use the blue springs and set the distance to 20.5mm which will give you 7000 rpms engagement, which is spot on. I did set it up that way and she really engages exactly at 7000. Now in my case I wanted to have 7500rpms. With the HIT clutch or any regular clutch you would struggle to set the clutch to engage 500rpms later, but not with this Polini 2G clutch. The manuals says turn the nut 1mm in to raise 500rpms. So I did that and look at that, she exactly engages at 7500rpms. Awesome isn't it? Not sure you guys remember but my clutch bell couldn't cover the HIT clutch completely which didn't really affect performance but still wasn't ideal. This is not happening with the Polini clutch and Wingbell. From now on and eternity I will only use the Polini 2G clutch, even for my future LC build I'll get the 107mm 2G Evo III clutch. Maybe it is the Malossi torsion control, maybe the Wingbell fins or maybe just my imagination but today with outside temps of 36 degrees Celsius I had barely any CVT fading. Here some pics.
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Post by oldgeek on Jul 22, 2017 12:28:19 GMT -5
That's good news! Nothing quite like arriving to a tune that you are happy with, it can be so frustrating along the way.
Thanks for the review on the 2G clutch. I have been considering trying one for quite a while. I am hoping that because it only has 2 shoes it will be sturdier than the 3 shoe clutches. It also looks to have beefier springs which could help it from fading as much. They only come in 107mm?
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Post by spaz12 on Jul 22, 2017 13:53:03 GMT -5
oldgeek , I'm sure they make it in a 105, or did. The 2G is getting more and more difficult to find, which is sad because it really is a great clutch. Another good thing about it is the way the springs work. They are compressed, as apposed to stretched on all the other clutches that I've seen. I'm no metal expert, but that seems to me to be better. I can tell you that the springs last a long time before needing to change them. tsimi , glad that you like the clutch, I knew that you would. That was also a nice review, especially about the rpm adjustment, something that I always forget to tell people. Next time you pull that all apart, mount the Malossi Torsion Control on the the clutch side. You'll need to slightly modify it on two apposing sides to clear the springs of the clutch, but that's easy and won't effect it or stop it from being put back the way you have it now if you don't like it. Anyway, I think that you will notice a nice little difference. EDIT: You have the 105 mm clutch, so that torsion control might not fit up in there.
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Post by tsimi on Jul 22, 2017 18:12:39 GMT -5
oldgeek The clutch you see in my pictures is the 105mm Polini 2G Evo II. The 107mm is the 2G Evo III which includes slightly stiffer springs(blue and yellow). spaz12 I tried to use the torsion control on the clutch side but it won't fit perfect. With the metal colored springs it was just OK but with the blue springs it won't fit well and I don't want to damage anything so I decided to put it on the other side. It clears everything as it is at the moment. With your 107mm Evo3 it shouldn't be a problem to use it on the clutch side which is what I am gonna do one day on my LC build. I think the fine adjustments is the big sales point for this clutch and as you said the springs get not pulled apart so clutch spring fading should take lot longer. The Polini 2G clutch is also used in the official Polini scooter races which says a lot. BTW. did you see the tool in the first picture? That is what I use to tighten the clutch nut. Mine is 41mm. Close it until you can't anymore and then give it 1-2 good wacks on the floor and it will tighten it good. Never had issues with it at max 11500rpms.
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Post by birdman on Jul 23, 2017 13:48:55 GMT -5
Excellent thread. Very informative. I just pulled the trigger on dellorto 21 so all the info in here will be very helpful. Also, after your good review of the 2G clutch I'm thinking of getting one of those as well.
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Post by tsimi on Jul 23, 2017 16:29:03 GMT -5
birdmanDon't forget the last jetting numbers 35/96 are with the stock airbox, snorkel out and modified. I didn't install the UNI filter so no idea what the best jetting for it would be. In the begining of this topic you can see a recommended starting point for the UNI filter jetting.
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Post by tsimi on Jul 25, 2017 6:10:06 GMT -5
Quick update:
I went back to 37/95 jetting. The 35 was a bit too lean. First thing I found strange was when starting the cold engine there was barely any 2T smoke coming out. Then I put in a new spark plug and went for a drive and...not good. The spark plug looked lean. So 37 went back inside and set the idle screw to 1.5 turns out.
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Post by tsimi on Jul 25, 2017 18:44:39 GMT -5
Another update.
Drove it like i stole it to work today. Once i arrived i right away removed the spark plug to check the color and... there is barely any color on it! WTF? CHT temps were good, not more than usual. Not sure what's going on here but I guess I'll up my jetting to 38/96 and see if that puts some color on the spark plug.
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Post by 'O'Verse on Jul 25, 2017 19:21:45 GMT -5
I'd leave it alone for a while longer. I read an article somewhere that a clean spark plug is the ideal tune. Something about the perfect temperature/ mixture self cleaning the plug. EDIT: (quote) In some cases, the insulator nose can usually be cleaned by operating the engine at higher speeds in order to reach the self-cleaning temperature. (From). www.ngksparkplugs.com/about-ngk/tech-talk/spark-plug-basics
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Post by oldgeek on Jul 25, 2017 20:31:26 GMT -5
That's the funny thing about the phbg. You can be lean at 1/8 throttle, perfect at 1/4 throttle, sputtering at 1/2 throttle, good again around 3/4 and rich at Wot. Lol! Getting it dialed in takes patience, and sometimes blind luck! I have a 21 mm on my 63 CC Kymco. It is too much carb for it IMO, and it is currently tuned so I get maximum power at around 3/4 throttle. I can feather the throttle at three-quarters and easily feel the power peak. However the engine temperature slowly creeps up if I stay at 3/4. At that point I go to WOT and it quickly starts cooling off and holds its top speed of 43ish. I actually like it the way it is now.
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