Carb Jets
- Thread starter joe-craft
- Start date
Hi Pablo -
New guy here. I ordered two 80/66 cc engines; they should arrive shortly. My question: I live in Colorado Springs, where altitude varies easily between 5500 feet and 7300 feet. To the east about 70 miles is 3500 feet or so. Should I be concerned about re-jetting the carbs? If so, to what? I plan on following the textbook to the letter for breaking in the engines. Then plan on routine 50-miler rides at max of 30 mph and 20:1 fuel ratios, and going longer up to 200 milers in a few months.
Thanks,
MikeJ
New guy here. I ordered two 80/66 cc engines; they should arrive shortly. My question: I live in Colorado Springs, where altitude varies easily between 5500 feet and 7300 feet. To the east about 70 miles is 3500 feet or so. Should I be concerned about re-jetting the carbs? If so, to what? I plan on following the textbook to the letter for breaking in the engines. Then plan on routine 50-miler rides at max of 30 mph and 20:1 fuel ratios, and going longer up to 200 milers in a few months.
Thanks,
MikeJ
I would not worry about re-jetting yet. Get the engines running and then dial them in for your conditions. They probably will be too rich for your conditions, but wait and see.
try it stock first or measure your jet size and needle then try it the way it is get it broke in then if its running wrong go to work on the carb. Keep an eye on leaks the head may loosen up and will need to be re torqued if the spark plug fowls out quickly then you will need to look at a leaner(smaller main jet). I live at 3200 ft mine seem to like about 0.001 smaller then stock but will work fine stock. All of mine run the needle at the stock position #2 slot down from the fat end(top of needle).
I think stock main jet is about 0.026 if the hole is wobbly you might have more than stock in dia.
Norman
I think stock main jet is about 0.026 if the hole is wobbly you might have more than stock in dia.
Norman
okay i got the jets in and they work, the head is a little long on the jet so i had to trim it to fit in the float bowl. my bike is up and running really good now. now next is new clutch pucks, when i find someone that make the trapizoid pucks. then a slant head perfomance carb ext. ext...
Joe
Is your clutch slipping? you might try to clean it with brake clean the what I call the real clutch plate is under the clutch pads the pressure pad is the part that you can take off to see the pads. It takes only a little bit of grease to make it slip. I guess you've played with the clutch adjusting? one adjustment is the main clutch spring that you might try which is posted in my corner it isn't real easy to do but it might help. I run one bike with a 36 tooth rear sprocket and the clutch will slip when I try to first start it. I just live with it.
Norman
Is your clutch slipping? you might try to clean it with brake clean the what I call the real clutch plate is under the clutch pads the pressure pad is the part that you can take off to see the pads. It takes only a little bit of grease to make it slip. I guess you've played with the clutch adjusting? one adjustment is the main clutch spring that you might try which is posted in my corner it isn't real easy to do but it might help. I run one bike with a 36 tooth rear sprocket and the clutch will slip when I try to first start it. I just live with it.
Norman
hey norm, the same thing happens to me it slips only when i start it, other then that it fine, but i would like clutch pads that are not made of old tires, if i can get a set of the ones EZ makes it be cool but id have to get a clutch gear with round pad in it, and i dont have the money yet to get one.
i thought of doing the spring adjustment but i dont want to tear my bike motor apart without the proper tools, all my proper tools are at my house out in the country, im in town for work so access to my garage is a no go.
i thought of doing the spring adjustment but i dont want to tear my bike motor apart without the proper tools, all my proper tools are at my house out in the country, im in town for work so access to my garage is a no go.
Sounds like until you either get more cash for a clutch change, it may not help, or access to your tools the clutch is going to be slipping when you start it. You could try the star nut see if it helps.
I could adjust mine as well do the big spring adjustment but, if I let out the clutch and roll the bike backwards pull in the clutch pedal, pop the clutch mine will start with out slipping, just the nature of mine. I'm just lazy I don't want to mess with the adjustment right now. The 36 tooth rear sprocket just seems to put more stress on the clutch because of the ratio of the final drive due the the smaller rear sprocket. I should fix mine....Naw Rufus says I'm a lazy guy I need to kick back in the recliner so he can catch up on his lap time, he's sitting right beside me wanting to go kick back in the recliner chair right now!
No kidding! Darn Kat!
Norman
I could adjust mine as well do the big spring adjustment but, if I let out the clutch and roll the bike backwards pull in the clutch pedal, pop the clutch mine will start with out slipping, just the nature of mine. I'm just lazy I don't want to mess with the adjustment right now. The 36 tooth rear sprocket just seems to put more stress on the clutch because of the ratio of the final drive due the the smaller rear sprocket. I should fix mine....Naw Rufus says I'm a lazy guy I need to kick back in the recliner so he can catch up on his lap time, he's sitting right beside me wanting to go kick back in the recliner chair right now!
No kidding! Darn Kat!
Norman
Guys, i am at 70 or 80m above the sea level. Anyone has tried larger jets?
I will buy a gigleur #80, is fine according to my altitude?
I have all stock parts, but im considering buy a performance air filter.
I will buy a gigleur #80, is fine according to my altitude?
I have all stock parts, but im considering buy a performance air filter.
Some jets are a percentage of flow and some are in mm dia. We just pulled the Main Jet from Our China Doll and it was 70mm (It was actually a very loose 65 but not quite a #70)They sell jet drills but they are very expensive and not the same as the number drills you might buy. The best is to purchase jet reamers. The are tapered reamers that are easy to use and get accurate hole size. There not cheap but cost about 1/2 as much as the jet drills. Be sure you know how to reed the plug before you start jetting.
The slide cut away, the needle jet and needle position and the main jet can all be changed and all effect different throttle positions. Carb Jet Reamers Carb Jet Reamers
The slide cut away, the needle jet and needle position and the main jet can all be changed and all effect different throttle positions. Carb Jet Reamers Carb Jet Reamers
Attachments
Last edited:
vicsvw Welcome to the forum, glad you joined us.
You will need to make a few post and become a active member before you post any links or pis. Sorry about that but we do this to help fight spam.
Edit or repost your post but do not add links or pics until you get a few more post.
You will need to make a few post and become a active member before you post any links or pis. Sorry about that but we do this to help fight spam.
Edit or repost your post but do not add links or pics until you get a few more post.
Just unpacked my China 66cc and found the Air filter was complently dry and mnual said nothing about oiling it. The foam filter will do little to no good unless it's oiled.
Life of the motor is clean air. Vic
Drills will not do the Job, you must have jet reamers ->Carb Jet Reamers
Life of the motor is clean air. Vic
Drills will not do the Job, you must have jet reamers ->Carb Jet Reamers
Last edited:
Anybody know what's up with the Dellorto Direct guys? I ordered jets over a week and a half ago. No word on shipping and they don't get back to you when you email. They have no phone number on their web site. Their customer service/relations suck!!
Someone have a phone number for them?
Jack
Someone have a phone number for them?
Jack
Did you get the email confirming your order? As I recall it had the phone #.
Other than that, I will agree they are VERY slow.
Other than that, I will agree they are VERY slow.