New Motor Issues??

My motor ran very well right from the start however I think that was an exception to the norm.

whoa... 15:1 is waaay too rich. the directions specify that because the chinese broke their motors in with 30 weight, not the super oils we have today. i'd suggest going to 24:1, and putting the clip back up a notch.

all these motors are gonna run different, but sounds like you're just dumping oil into the motor and it can't swallow it.

I'd go to 24:1 or 32:1 and try a new plug.
Also, is it four stroking most of the time?

"These things are pretty much all the same, inconsistent"
BikeguyJoe

Just always thought that was funny.

Mac said:

Thanks guys, I'll adjust the ratio, use the 16:1 in the weed eater... Odd how the Silver jet ran well... what am I thinking, applying the "rational" theory LOL

Black jet runs like poop. 1/2 throttle max, it's only cooperation is simply Staying running. At WOT, just the sound changes(only did this to troubleshoot) If I let the rpm's increase at 1/2, it 2 strokes on SLOW acceleration, when it does the 2 stroke rattle(when it should be comming into power band) that's it. deadsville. I will re-adjust mix and go and get a couple of NGK B5SH plugs. Last question, why no smoke if the mix was that fat?
2 stroke mix was Amsoil synthetic. (don't shoot me for breaking in with synthetic

Thanks again!

Mac

Click to expand...

Nothing wrong with breaking it in with synthetic..

Check your fuel system. I recently had two different problems that affected performance on new kits. First was a petcock. It had a piece of the rubber gasket partially occluding the fuel passage way. This caused starvation issues. The second issue I encountered was a loose main jet. Both these problems caused similar performance to what you are experiencing. Also, the stock plugs are crap. Throw them away and replace with an NGK plug from napa. Best advice I can offer is to take some time and disassemble and check everything on a new kit prior to attempting to utilize it.

I agree with Gareth (his two posts so far are rock solid!)

What DOES your plug look like now?

i am retired and make a good side living installing these china girls into a costomers bike. i'e done over 30 of them so far.
many of the retail sellers DEMAND 2-stroke synthetic at 16 or 18 to 1 for the first 200 miles. bikeberry will void your warranty if they open it up and synshetic was not used.
jim (the manic mechanic) uses mobil 2-stroke at 6 or 7 ounces per gallon for breakin and reccomends 20 0r 25 to 1 thereafter.
i have had 3 motors come back within 3 weeks siezed up and they all admitted runnung 32/1 from the start.
yes, during breakin they do not run as well due to too much oil for good performance, live with it.
when you drop to 5 ounces per gallon (25/1) horespower, milage and performance improve greatly.

stay dry

gubba

Hi Mac,

We just finished a Grubee angle plug kit install and we had very similar results as you. I went ahead and sealed up the carb intake and the cap of the carburetor with an o-ring. I think that helped. It still doesn't run like my first Grubee but, it's not broken in yet and we're still running 16:1. I'll be very interested to see how this engine reacts once it gets broken in properly. We've got about the first gallon of gas through it and, it SEEMS to be getting better. We'll see.

hey mac
where in maine you at, there are a bunch of guys on the blue hill peninsula, gotta be at least 10 now

Good to hear that you're catching up with it MAC. We've got ours to where it will 4-stroke at light throttle, up to about 2/3-3/4 throttle. Then it still has a slight ping. I'm thinking of opening up the jet a little bit to get more fuel at WOT. Then it should be good. BTW: I found a rubber o-ring at AutoZone that is intended for oil pan drain plugs. It has a shoulder on the inside of the o-ring with a hole that is just large enough for the return spring to fit into. I've installed two so far, one in this bike and one in mine, to see if it would make a difference. It helped the lean runner and, when I installed it in my bike, I actually needed to screw in the idle setting screw to keep it running. My line of thinking is that it was leaking air through the cap and when I replaced the old o-ring with this one, it cut off all the un-metered air that was bleeding through so I needed to open up the idle setting a little bit more. Not a bad thing in my opinion! I wish I had gotten a photo of the o-ring before I installed them both but it's an Oil-tite! black o-ring (PN66451) and you can get them in the area where they have the oil plugs and such. I hope this helps someone else out!

I'm guessing you can't get it to run wide open?? I sort of skimmed through the posts.
You said your not wanting to swap out carbs with the engine that runs good. That is one thing I would do if it then runs good then that would tell me it is the carb causing the problem.
Paublo(from sick bike parts) had a carb that would not let the engine run much over idle. he sent me the carb I put it on my bike and it ran just like his ran horrible.
What I found was his needle was not tapered correctly. I redid the needle and tested it on my bike until it was working good I returned it to him and I don't know or remember if he ever used it.
you can mic the needle and see if its tapered correctly I think that the clip end it should be around 0.080" and at the pointed end around 0.068" not much of a change.(not sure of this as I don't have a carb with me right now so these measurements are more than likely wrong)
You could swap out just the throttle slides needles off of the good engine and try it on the poor running engine see if it helps and while your doing that measure them to compare them.
I guess you checked for all the normal spots for air leaks and also at the cranks main seal for being leak free and in place so they are not being rubbed? you did seal the carb to manifold with silicone and not using an o-ring? you also redrilled the main jet what was its size before you did this?
you checked that the throttle slide will go completely open and closed? spark plug gapped at around 0.025" fuel mixed at around 25 to 1 or more leaner?
I'll relook at these posts and see if I can find any more things to check or look at.
you don't have any black oily stuff leaking around on the engine case? sometimes that is a sign of a case gasket leaking. new engines do run crappy but sounds like yours is dropping a load in the bed right out of the box.aka running very poorly from the start I'm leaning towards it being the carb. with not being there to see it myself its a little hard to pin point the problem.
Norman

Mac
This is a new engine right? could be it will get better as you Break it in. I wonder how thick is the base gasket on this engine can you tell if it has only one gasket or a couple? I've seen one engine that I bought had 3 base gaskets I removed them and installed my own home brewed gasket it helped it run much better changed the port timing a little I guess for the better.
Could be the timing is off too they are not adjustable unless you make a key then its a hit or miss thing. When I get the time I'm going to try an adjustable timing set up.
I have one engine that will run like a scalded dog it sounds like a high performance dirt bike engine compared to the rest very fast on throttle response. I need to sit down with this engine and do some serious readings on timing of the ports and ignition etc.
Back to your engine if you match up the gaskets intake and exhaust clean up the weld boogers in the flange part in the exhaust just smooth out the flow for the gases that will help. even the cylinder to the case areas and get the gasket there to match the cases so there is not any gasket hanging out in the flow.
I use poulan syn. 2stroke oil with regular cheap gas the lowest grade 86 octane mixed at 40 to 1 I've found this to work the best for me. Premium gas didn't do a thing for them. Alcohol will get a little boost in performance but to run properly you have to shove a bunch through the engine which isn't practical for street use mileage changes to blocks per gallon plus you have to use an oil that will mix with alcohol which is more expensive. I went to a main jet of about 1/8" and it still didn't run right needed to change the needle to the richest setting and it still was lean so I quit that test. by the way happy new year!!! 2010 is here.
well I need to get off and go to bed