New Metrakit 65...yeah

I finally took the plunge and bought a kit. Got the 65cc metra-kit and I well into the break-in. 50 miles so far and no seizes :) Now I have some fine tuning questions that I know you moped experts can help with.

First the setup:

1978 Newport with 15mm bing with 82 jet, high flow filter, a 15mm intake (the square bottomed one) and a bi-turbo exhaust. I have not ported/port matched my kit to the bottom end (I know that I am missing out, but the porting thing still makes me nervous)

Now the questions:

I know that most people think that bings just suck, but I have a 12mm, a 14mm and the 15mm and all jets from 56 - 88 so I really don't feel like switching. The problem is that the thing 4 strokes like crazy from 0 - 1/2 throttle, is happy and sounds great from 1/2 to 3/4 and then above 3/4 actually slows down. What gives? Do I set the needle different, or is my jet wrong? The plug chops look good after I have ridden a ways at 3/4 throttle and look oily after a ride at 1/4. Also, it starts right up and idles great when cold, but once I have ridden it a mile or 2, if I stop, the ped dies out, no idle no matter what. Is this jet/bing carb related too? Should I open up the bottom of my intake to round it out? Any help or ideas would be greatly appreciated.

Re: New Metrakit 65...yeah

Sounds like you are just too rich.

Re: New Metrakit 65...yeah

Then why would it look good at 3/4 throttle? I can't find my 80 jet either.... I will maybe try a 78 tomorrow

Re: New Metrakit 65...yeah

i'm running the EXACT same setup (pantyhose airfilter though), but i'm only about 20 miles into the break in. at first it was terrible in the midrange, but i moved the needle to the second highest position and its very happy. it sounds like your needle is already in the right position if it pulls hard from 1/2 - 3/4 throttle. full throttle is completely controlled by the jet so you should take a ride at full throttle for as long as you can and plug chop. my guess is because i'm basically using no airfilter and my 82 jet is working out you may need a 80 or 78 like you mentioned. give it a try.

Re: New Metrakit 65...yeah

it lks good at 3/4 because yu arent open and there is less gas and so you arent rich then.

the other guy has less problems cause his panty hose let ijn more air then your high flow filter. lower your jet and yes, the idle issue is probably due to the bing, but you could also try setting your idle and tuning that up when it is warm instead of cold till you get it to stay on.

Re: New Metrakit 65...yeah

Update... 78 was a tad too lean. I am awaiting a new 80, since mine is still AWOL, from mopedshop. When it gets here, I think it will be right on. I screwed my idle screw in almost all of the way, and now it holds a steady idle (although races like a bastard when it's cold). I also droped the needle so the ring is in the top notch, and that helped with my 4-stroking on the low end.

BTW, what would happen if the piston were put in upside down becasue you don't read spanish and assume the arrow means up.....

Re: New Metrakit 65...yeah

arrow is down

Re: New Metrakit 65...yeah

it sounds to me like your 82 jet was correct. main jet matters mostly from 3/4 to full throttle. from 1/4 to 3/4 is all about needle setting. i think you should raise the needle, and put the 82 back . . . or maybe an 80, since you said you had powerloss at full throttle. also, visually check that what you think is 1/4, 1/2, 3/4, and WOT are actually 1/4, 1/2 etc. sometimes the throttle cable is the wrong length.

Re: New Metrakit 65...yeah

The arrow goes down. If it idles really high, check for air leaks.

Re: New Metrakit 65...yeah

Ok, so maybe I should have been more direct. When

I first put the kit on, I put the arrow going up, ran it for like 30 miles, then found the spanish-english translation that said arrow points at exhaust. Oooops. Anyway, I fixed it, the arrow now points down, but my problems with jetting weren't solved by the upside down piston deal.

I am again running the 82 until the 80 gets here. thajnsk for all of your help so far. this site is great when it comes to helping the first timers.

Re: New Metrakit 65...yeah

Fred,

Keep us updated. I have the exact same setup minus the metrakit, which I plan on getting this summer. Hows the speed/acceleration with that setup?

Re: New Metrakit 65...yeah

minus the metrakit is basically a completely different bike. just so you know.

Re: New Metrakit 65...yeah

OMG!! REALLY? THXXX!!!

Re: New Metrakit 65...yeah

I have the same carb, intake, exhaust, air filter. I'm PLANNING on getting the 65cc metrakit and I was just wondering how it performs with those components since I will shortly be running an identical bike.

Re: New Metrakit 65...yeah

Still waiting for the jet. I also want to take it easy for a little while longer till the kit is good and broke in, but it seems to be doing much better than the stock. I also am running a 14 x 38 gearing right now which is slightly higher than a 16 x 45.

Re: New Metrakit 65...yeah

What you need there Fred is a 2.15 needle jet. That will fix your idle problem. I believe the carb comes with a 2.17 needle jet. The 2.15 is the smallest I've seen for a Bing with a 4 position needle. It will lean out your idle and will make you have to readjust your needle settings for mid throttle. I'd call around and see if anyone has it.

Re: New Metrakit 65...yeah

wait, the needles come in different sizes? how do you tell what size needle it is?

Re: New Metrakit 65...yeah

The needle jet is the part the needle slides into. It is also the part the jet screws into from the bottom on a Bing. It has numbers on the side of it. This is the size of its internal diameter. Stay away from numbers with an A at the end. These are only for 2 position needles. And the orifice is sunk in a bit. I wouldn't want you to hang a throttle. Mopedwarehouse will probably have the 2.15 in stock. I checked Handybikes for you. I didn't see it there. Which suprises me a bit. Usually Handybikes has everything like that.

Re: New Metrakit 65...yeah

Needle issue aside, my compression with a 50cc high compression head is only 150 psi is that normal?

Re: New Metrakit 65...yeah

150 lbs of compression is normal. Did you get a jet yet?

Re: New Metrakit 65...yeah

Yes. Sadly the 80 jet doesn't seem to be any better. Less 4 stroking in the 1/4 throttle area, but still power loss above 3/4. I seem to remember that power loss at full throttle means too lean and 4 stroking at full throttle is too rich? Should I go with a bigger jet, I have 80 - 88 now. Just as I got it all put back together with the 80 in it the thunder storms rolled in, so I didn't really get a chance to run with the 80 jet full out. Should be nicer tomorrow and I'll try some more jets and see. Another piece to the puzzle... I know 82 seems big, but my stock cylinder was running the 82 with the same set up. Shouldn't the 65 cc need more jet? Also, I can still see the crosshatching on the inside of the cylinder. That means it still needs some breaking in right? Thanks for all of your help.

Re: New Metrakit 65...yeah

I don't know about iron cylinders, but I had a stock chrome bore cylinder with faint hatch marks. It had about 1000 miles on it, and it was broken in. Start with the 88 and go down if it is too rich. You really need to do plug chops or have a head temp gauge to get an accurate idea.

Re: New Metrakit 65...yeah

No, they are not faint. They are very obvious, which means I have some more slow riding to do. The directions say 300km = 190 miles and I've only gone about 75 so far, so I am not very surprised. BTW, Is there a point where you notice, "hey the rings have seated" It seems like that would improve compression since the rings would fit tightly against the cylinder.

Plug chops is the other thing. I was running a b6hs in the 50cc, and it ran beautifully. The instructions in the metra said b7hs, and that thing looks like #23 here:

http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

It is bone white, which means too lean, which means I need to up jet. But then I am back to my low throttle 4 stroke issue.... I don't know anymore. Hopefully tomorrow will be sunny and warm and I can blow off the yard work and figure this damn thing out!

Re: New Metrakit 65...yeah

Did you spray everything with carb cleaner to look for leaks? You said yourself that it idles high and the white plug is another pointer. You'll notice that the bike idles smoother and that it needs to have the idle screw turned a little. I forgot if it idles faster or slower though. Maybe somebody else here will chime in.

Eric

Re: New Metrakit 65...yeah

Woo hooo. Looks like we have a winner. Jet #84, come on down! I pulled the old needle jet out of my 12 mm bing and it was a 2.20 which was way too big. So big I couldn't get it to idle. I put the 84 jet in with the 2.17 that came with the 15 and no more power loss at full throttle. I need to try the 86 just to see how that does, but the 84 is doing very nicely. Next up different gearing for more speed :)

Re: New Metrakit 65...yeah

what pipe ya running?

Re: New Metrakit 65...yeah

bi-turbo

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