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Post by riker140 on Feb 13, 2006 18:12:33 GMT -5
New roller weights have arrived.
Jet's are due tomorrow.
So I have been checking out re jetting a carb.
I almost wish I hadn't because all the info I found said this is a very delicate and complex thing to attempt. Note the Attempt that should scare off anyone faint of heart. The one thing I did find that most of you already know is the number for a jet such as 424-21-035 means the orfice is 0.35mm in diam. thus if the last three numbers are 110 that means 1.10mm diam. I had drilled my high speed jet out with a #60 drill0.040" diam or 1.016MM. The high speed jet stock starts at 085 or 0.85mm next step is 0.88 next is 0.90 next is 0.95
so the 60 drill is 5 steps above stock. The results is the low and high speed jets can not work together.
So I am going to change the low fro 035 to 038 and the high to 088 and then try 090
Air box has been remove replaced with a UNI filter spark is iridium NHK. Muffler stock. 4 stroke 80cc
Top speed 50.1 laser measured
problem area 20 to 30MPH
Dave
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Post by Admin on Feb 13, 2006 18:39:46 GMT -5
It sounds like you have a plan. Where did you finally end up finding your jets? What weights did you get on the rollers? If you can get that 20-30 mph thing worked out, you will have a little rocket!
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Post by Admin on Feb 13, 2006 19:24:26 GMT -5
Hey Riker, since my main scoot is in pieces on the floor, I just broke out my 80cc and checked out the 20-30 mph range. I'm doing it in 4 to 5 seconds. That's 80cc, main jet drilled with #60 drill (0.040") and 6 oz. roller weights. Everything else is pretty much stock. Also, easy to forget is to make sure you've got proper air pressure in the tires. Let them get 5-10 lbs under and it'll kill performance.
Lee
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Post by riker140 on Feb 13, 2006 20:00:20 GMT -5
WWW.rageperformace.com Jets Roller weights 3g thru 8g set of three each plan is dependent on what the stock rollers weight. shooting for 34,34.5,35,35.5,36 will start low as I don't need 50MPH 40 would be fine is I can get their in less than 12sec. Yes it will be a rocket if I get their. Air pressure checked each time I make a speed/time run. I am searching for the type of carb I have. I know it's a Keihin but is it a CV, CVK, PE, PW, PD, P??,  , . all are different. Question have you changed your float needle setting? Still working on tuned exhaust but that come later
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Post by Admin on Feb 14, 2006 8:31:29 GMT -5
If your carb is a Keihin, it will be marked with the type on the side. I haven't touched the needle. My 80cc has nearly as good acceleration on level ground as the 150cc. The difference comes hitting the hills. Your post got me curious so I braved the cold this morning and checked. It does 0-40 mph in 15.75 seconds.
Lee
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Post by riker140 on Feb 14, 2006 13:35:39 GMT -5
Lee: That's my target under 16 seconds to 40mph. Then add the tuned exhaust and get under 16 to 50MPH.
That's the plan!!!
Dave
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Post by Admin on Feb 15, 2006 19:20:23 GMT -5
Hey Dave, have you done any more on this? You can get it under 16 seconds, I have no doubt!
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Post by riker140 on Feb 17, 2006 16:36:56 GMT -5
Up date changed low jet to 0.38mm high jet to 0.90mm.
Put it all back in started in less than a second blew mine mine. It was taking about a minute if I had taken carb off before it would start. idle and main speed screw unchanged.
idle was 3020RPM very promising to solve low end problem if idle jumped that much that would have to be the low speed jet effect. just one problem I have a huge leak from gasket area. So set all aside until later. will remove carb and reset gasket o-ring. Damn, but progress and I am excited. Hay have a nice trip to INDY wish I was with you.
Dave Riker
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Post by Dave on Feb 19, 2006 14:06:21 GMT -5
Sunday 19 Feb Have replaced o-ring and carb back into scoot. 50cc/80cc no air box Low jet 0.38mm hight jet 0.90mm 0-20 MPH 2 second 20-25 2.5 seconds 25-30 6 seconds total 10.5 sec top at 50 MPH 5 seconds no change in speed just got their faster. yah!! total 15.5 seconds target 12 seconds and under. Idle smoothed out 1950 - 2000RPM Hight speed screw tured out 3 turns now was 2.75 to cold to run many test runs so did not check RPM's But this is a big change in the 20-30 MPH range which was 14seconds now down too 8.5 seconds. Next step change weights to 34,35 or 36 grams Will start at 34 grams for first test.   Dave |
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Post by Admin on Feb 20, 2006 14:32:53 GMT -5
Way to go Dave! This will be a guide for others trying to achieve those results. You just had to beat me by a couple thenths of a second, didn't you? Lee Sunday 19 Feb Have replaced o-ring and carb back into scoot. 50cc/80cc no air box Low jet 0.38mm hight jet 0.90mm 0-20 MPH 2 second 20-25 2.5 seconds 25-30 6 seconds total 10.5 sec top at 50 MPH 5 seconds no change in speed just got their faster. yah!! total 15.5 seconds target 12 seconds and under. Idle smoothed out 1950 - 2000RPM Hight speed screw tured out 3 turns now was 2.75 to cold to run many test runs so did not check RPM's But this is a big change in the 20-30 MPH range which was 14seconds now down too 8.5 seconds. Next step change weights to 34,35 or 36 grams Will start at 34 grams for first test. Dave |
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Post by Dave on Feb 20, 2006 18:07:00 GMT -5
Lee thanks for cudo's But I have only tested four runs and not over a measured area. Looking forward to pic's and your impressions and some of the good's you learned. I think the numbers will change when I get to the nitty gritty runs. I found what my carb type is it's a keihin CVK 18mm. Now I need to find how to adjust the idle and pilot screws and I don't know where they are on the carb. both have a relation to idle speeds mine I thought were level but as the engine got hot all of a sudden the idle control was lost. Checking I found changing jets as I have done requires a change in the setting of these two screws. One is inside near the low/high jet and the other is outside at the bottom. But which is which is not clear. More searches. Welcome back I think you were missed! Dave |
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Post by Admin on Feb 21, 2006 7:39:55 GMT -5
Dave, the idle screw is on the right side of the carb where the throttle cable wraps around the spring loaded wheel. Clockwise will raise the idle, counter-clockwise lowers it. The adjustment should be done with the engine warmed up. I like to run mine on the high side. On my 80cc I run idle at 2000 rpm.
Lee
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Post by Dave on Feb 21, 2006 8:29:59 GMT -5
Lee thanks but I need to adjust the idle jet one is in the bowl inside the carb and on is outside and sealed over with some sort of material. those two are the screws I was refuring too. Can't remeber what the are called different web site called then different thing. Not explanied which was which. I have to travel today so will not be back till late pm. No testing today. Dave |
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Post by Dave on Feb 21, 2006 19:45:09 GMT -5
Got back earlyer than I thought.
Ran some quick test. Oh I found part of the Idle problem sucking air on intake to cyclinger. Still not perfect on idle but has settled out at the 1850 1970RPM area as before. but had to screw idle screw on right side down to it's limit. Which tells me that its not getting enought gas at idle. The two screws/jets, depends on who you read their writeup witch is which. the pilot jet is inside bowl and the pilot idle jet/screw
is seal with wax I think and is on the left side on intake side of cyclinder. Now test 20 to 30Mph Rpm's flated out starting at 20 and 6000+ RPM's and toping at 6500 at 30MPH. Top speed now is 46MPH+ a tad. 8500PRM's times are not as first reported but very much improved. I intend to change to the #88 hi-speed jet and change weights at the same time. reason I feel that the gap between the #38 and #90 is to big a step and is hindering the transition for low to high in combination as charts show ovewr lap of the two jets a mid range.
What ya think! :-)
Dave
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Post by Admin on Feb 21, 2006 22:08:32 GMT -5
I think you are talking like a crazy man, Riker. I don't know anything about these screws you are talking about. You should be able to do all the fine tuning you need with jets, idle screw and maybe the air/fuel mix screw. Four stroke carbs don't need nearly the fine tuning that two strokes do. All you need to do is make sure that air/fuel mix is in balance. Playing with stuff behind sealed wax could take you places you don't want to go. Just my $0.02.
Lee
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Post by Dave on Feb 21, 2006 23:33:33 GMT -5
Lee look in the photo section of the geely group for "riker's" their you will see the screws/jets I am talking about. On all the web sites on keihin carb's CVK type address this problem that I have. roy seem the same as you he said he also knows of no such adjustments. but I have seen both these scress will only one the other is covered in wax(i think it's wax ) do not plan to do anything until I adjust the hi sped to #88 and change weights --test and see where I am. But like i said the idle screw is maxed out. and like you i think 2000rpm would be better for idle rpm's the best i get is 1850 to 1970rpm idle. Dave |
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Post by riker140 on Feb 25, 2006 11:04:40 GMT -5
Feb 25 update:
Run test on 38-90 jets still having to much problems with idle
Changed to 38-88 jets, found idle problem it seen both the high speed jet and the low speed jets had a rough thread on ID about 1 to 2 turns from bottoming out I had stop at the rough spot. found when I put the 88 in it hit the rough spot but because I was using a wrench and screw driver it went right pass. so check the 38 low sp jet and sure enough it went down about 1 1/2 turns.
So ran some test idle has improved and is stable. I think the auto choke is causing the problem. Run and let off the throttle and the engine rev's stay up wait about 20-30 seconds and it returns to normal set idle (1870-1980 new idle rev's)
OK 0-20 about 2 seconds maybe less
20-30 six seconds total 0-30 8 seconds 30 to 40 6 seconds total 0-40 14 seconds.
still think 10 seconds is do-able 0- to 40.
Well I tried to change the weights and the master is right get an impact wrench. And you were right-on in nut size
11/16 or 17mm I have a 17mm 1/2" drive. But breaker bar
is just not enough and I do not want to damage the gear or the fan.
Cu do-s Lee 10 seconds here I come (will settle for 11 or 12)
Dave
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Post by Admin on Feb 25, 2006 11:22:01 GMT -5
I don't think you will ever hit 10 seconds 0-40 with an 80cc. You are doing real well for sure. Rollers make a difference but it's a very nuanced tuning and I think to do it right you have to try several different weights until you find just the right combination. Also, when you replace that variator nut, it's really got to be torqued or it will come loose and the whole thing will come apart. Don't ask me how I know.  |
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Post by riker140 on Feb 25, 2006 12:15:15 GMT -5
Yeh! If you ask I'll have to kill you. Type of thing right.
Thanks Dave
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Post by Admin on Feb 25, 2006 13:23:32 GMT -5
Let's just say there is something to be said for doing things right the first time. You really need an impact wrench to get it on tight enough. If you are using one of those cheap electric ones, let it whack 25-30 times. I've read where some guys use Locktite just to be sure.
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Post by riker140 on Feb 25, 2006 18:05:38 GMT -5
Lee thanks
I have another problem the gaskit was glued to both sodes of of the housing. So it split in several places. I tried to remove the gasket with a razor blade didn't work.
Thought of just scraping it off but saw a large part of the case covered by the gasket one large opening and a smaller one. at the rear of the case over where the gear box is just behide that location. So any thoughts?
Dave
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Post by Admin on Feb 25, 2006 18:26:14 GMT -5
The gasket on this is not really significant. Just tear off any hanging loose and slap it back together.
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Post by riker140 on Feb 28, 2006 18:27:23 GMT -5
Lee: Got an impact wrench today it's a battery 18volt Ryobi with a 1/4" hex drive so hopfuly tomorow I'll change weights. Ran another test high speed did not drop as much as reported it's 47+Mph low end is much improved. I will weight the stock weights and then make a judgement as to what to go down to. I was told by a dealer of this model that if I had a 50cc/80cc the weights are 8.5 grams that's 51 grams total a long way from 36, you, and roy, 34.5 so I have to check and hope he is right. Because if he is that means I can keep my top end and improve the hell out of the low by droping to about 40/45 grams. Everyone on the geely site should be proud of what they and you have done for that guy needing the cover.  |
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Post by Admin on Feb 28, 2006 21:29:56 GMT -5
Those test on an 80cc can be a little misleading. A 3-4 mile an hour headwind can make all the difference. I doubt your weights are as heavy as they told you. If you don't have a scale to weigh them, you might try a polite approach at the post office while buying a book of stamps. They have scales that will weigh them. Every scoot and rider is different but I'm guessing that around 36 to 42g total will be right there for you.
Lee
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Post by riker140 on Feb 28, 2006 23:41:04 GMT -5
OH I forgot to tell you my pharmacy is going to weight my stock weights their scale has 0.001 gram accuracy.
Gee I am having so much fun I am going on way over 50 and I feel like I am 16teen again. I can't tell you what all this means to me It's as if I'm 16 again and my dad just gave me a motor bike. For you young ones thats a 32" bike with a motor, belt drive. I lied in my profile did not want to be an old fart just getting in the way. I trust your discretion.
Dave
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Post by Admin on Mar 1, 2006 9:08:51 GMT -5
LOL! OH I forgot to tell you my pharmacy is going to weight my stock weights their scale has 0.001 gram accuracy. Gee I am having so much fun I am going on way over 50 and I feel like I am 16teen again. I can't tell you what all this means to me It's as if I'm 16 again and my dad just gave me a motor bike. For you young ones thats a 32" bike with a motor, belt drive. I lied in my profile did not want to be an old fart just getting in the way. I trust your discretion. Dave |
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Post by riker140 on Mar 1, 2006 15:15:55 GMT -5
Further trouble in river city that begins with an "I" that's impact my friend and it's trouble in river city.
It's not a high torque impact but min is 66 Ft lbs will that is not enough it can't budge the damn nut so put it back together and just took a ride. Any thoughts I have a 24" breaker bar.
I did find this-- constant rpms level ground 20MPH sustained rpms are 6200 - 30mph sustained level 7200 - 40 mph sustained level 8200 - off the scale 9800 sustained and level
So I don't think I lost my top in this change. but will have to get some help to check speeds. I still need to chang weights
I am going to find some one with a moble shop and see if they use an air gun and remove the nut.
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Post by Admin on Mar 1, 2006 15:27:33 GMT -5
Hey Riker, 66 ft lbs ain't gonna get it. Harbour Freight has a 12v wrench on sale for 1/2 price $20. It's the one I used and it worked fine. Here is the sale. tinyurl.com/asba3When replacing the nut, I let it whack it 25-30 times just to be safe. |
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Post by riker140 on Mar 1, 2006 17:58:53 GMT -5
Thanks just ordered one. Dave |
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Post by riker140 on Mar 12, 2006 17:57:25 GMT -5
I still have not got the impact for harbor, Roy emailed me he has put sliders in 6.5grams toped 58MPH and low end awsume.
I changed gas filter to day a PUralator and that has made a big difference in the idle also It doesn't log down on get-up-go throttle like it was. I am going to go back to the #90 hispjet from the #88 My high end is down to about 47MPH (I fuge a little)
Dave
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