[michanic220]

Just joined this site, looking for help and specs on this dirtbike i just got, im pretty sure its a CRF70, its a honda motor and im 99.9% sure its a CRF70. its blowing back threw the carb a little but runs alright, doesnt have alot of compression tho (not sure on PSI) im a mechanic so i know alot about this kinda stuff, just need the specs to do it. i've came over from car stereo.com and audio kingdom. (the real one)
can anyone help me with the specs, i googled them and found this site, lol. and im seeing .002 and .003. also is there a number on the engine block i can find to identify this motor? all helps appreciated, thanks. -joel.

[Asmith]

1. When the motor is cold, take the cover off of the top/front of the head.. honda uses a 17mm hex threaded cap.
2. Take the ignition cover off the left side of the motor.

3. Take out the spark plug and turn the motor to TDC, there should be some resistance to get the lifters over the lobes and then it should be fairly easy to get it to TDC.

4. Loosen the lock nut on the tappet adjuster.
5. Loosen the tappet adjuster and put the feeler gauge between the top of the valve and the adjuster.
6. Lightly tighten the adjuster to the point where you can still get the feeler out without much force.
7. Tighten the lock nut being sure that the adjuster doesnt move THEN remove the feeler.
8. Turn the flywheel over once to tdc and make sure that you adjusted the valve at the proper time, it will either be way loose or too tight for you to move. it should be under pressure and not loose.
9. Turn the flywheel over again and double check the gap.
10. repeat steps 4-9 for the exhaust valve.

The valve clearance should be .002"

[Asmith]

[michanic220]

alright, im just kinda sketchy on adjusting valves because i adjusted a tecumseh to .006 and .008 for exaust and it wont fire anymore.. so i should adjust it on the TDC mark on the compression stroke right? thats what the other guy told me. and the frame number is

LPPBDF7074K9K1487

i do beleive its a older bike.

[Asmith]

alright, im just kinda sketchy on adjusting valves because i adjusted a tecumseh to .006 and .008 for exaust and it wont fire anymore.. so i should adjust it on the TDC mark on the compression stroke right? thats what the other guy told me. and the frame number is

LPPBDF7074K9K1487

i do beleive its a older bike.

Post a picture of the bike. I ran that VIN number and it doesn't exist.

It certainly isn't a CRF 70F.

[michanic220]

thats weird, i might of wrote down the wrong number, idk. is there another number i can get off the engine? where would it be if so? i dont have any pictures but can probly find one online.

[michanic220]

alright, this is the exact same motor BUT mines a 4 speed w/ clutch.

and i cant look up the vin number because this motors been swapped out from bike to fourwheeler and so and so.

http://cgi.ebay.com/KIDS-4-STROKE-DIRT- ... otohosting

if that helps?

[Asmith]

[michanic220]

i cant find one on the motor anywhere, are they stickers? cuz i cleaned the motor lastnight and there isnt any seriel number on the motor anywhere.

[Asmith]

If it's a 4 speed with a clutch then it's not a Honda.

Honda's are automatics in the 50's and 70's.

What you have there is a Genuine Chinese Knockoff commonly referred to as a Chonda.

It could have any one of a number of different engines including but not limited to:

Loncin or Lifan or Ducar or SunL or Zongshen or...

You get the point.

Good ruck.

[michanic220]

yea, i wasnt sure if it was or not, cuz it looks like a honda motor, but the break cables and stuff had chinese on them which got me wondering, lol. do you think the valve specs would be around .002-.003? or no idea? thanks for the help man.

[Asmith]

Yeah. They should be the same, they are just Chinese copies of the Honda platform.

Here's a site that has Lifan (the biggest supplier).

They have a 70cc with a clutch and a 4 speed.

http://www.hooperimports.com/dept.asp?dept_id=02

[michanic220]

thats it!

http://www.hooperimports.com/product.as ... c%5F4M%2Di

[michanic220]

actually this is the one..

http://www.hooperimports.com/product.as ... c%5F4M%2Dt


my bad, there both the same motor but mines 4 down to shift, not one down 3 up.
i guess just different transmissions?

[230@#)]

hey back to valve adjustments I got a 1985 Xr 80 and the valves are ticking alot. is the valve spec the same for the old 80 as the new 70