Engine mount bolts

#1
Hello I am new here an I am going to be getting a mini bike kit in the near future. I have no idea what bolts to mount the engine with. Hex bolt with lock nuts is my guess. The engine is a HF Honda clone. Thank you for the help!
 
#2
I may be weird, but I use the best bolt I can find. I go to the auto parts place by my house and use grade 8 or 10, use the same grade nut. Lock washer and double nut. I go riding all over the hills and last thing I want to worry about is engine trouble. I will admit my methods are a little overboard. But I have had bolts come off before from the engine vibration.
 
#3
Any grade 5 or 8 bolt with lock nut, if using nylon type and you can thread it on all the way by hand replace it with a new one. Always use a washer under bolt head and nut to spread out the clamping force-less chance of cracking block or warping motor plate.
 
#7
i usually use zip ties to hold my engine in. it's worked well so far.
lmfao. black or clear?

For Honda and Honda Clone gx160 (5.5 hp) and gx200 (6.5 hp) Engines
This is the size list so far of the bolts and some torque values. Please let me know if you have anything to add. Please note these are the stock sizes and torque specs, please when installing aftermarket parts consult the Manufacture for proper bolt size and torque specs.

Bolt /size /(torque foot/lbs)

Connecting rod bolt M7 x 1.0 (9 ft/lbs)

Cylinder head bolt M8 x 1.25 (17 ft/lbs)

Flywheel nut (special nut) M14 x 1.5 (54 ft/lbs)

Rocker arm pivot lock nut (special nut) M6 x 0.5 (7 ft/lbs)

Rocker arm pivot bolt M8 x 1.25 (17 ft/lbs)

Crankcase cover bolt M8 x 1.25 (17 ft/lbs)

Muffler mounting nuts M8 x 1.25 (17 ft/lbs)

Cylinder head intake bolts. M6 x 20 1.00 (17 ft/lbs)

Cylinder head exhaust bolts. M8 x 25 1.25 (17 ft/lbs)

Crank Shaft bolt. 5/16"-24 x 3/4" fine thread (30 ft/lbs)

Crank case mounting bolts 5/16"-24 x 3/4" (17 ft/lbs) (some engines use M8 x 20 1.25 pitch) (17 ft/lbs)
 
#8
Hello I am new here an I am going to be getting a mini bike kit in the near future. I have no idea what bolts to mount the engine with. Hex bolt with lock nuts is my guess. The engine is a HF Honda clone. Thank you for the help!
Dear 96-1500, If you're looking for the absolute maximum in holding strength and anti-vibration characteristics; then go to your nearest airport where they do repairs and get yourself some "AN" type aircraft bolts and castellated nuts. They have a shear strength of 125,000 pounds and a tensile strength of 250,000 pounds. The ends are drilled and when you tighten the castle nut down you put a cotter pin through it to keep it from loosening. If they can hold the wings on a fighter jet they sure as hell will withstand anything your minibike can throw at them. And they are relatively inexpensive. Most minibikes use 5/16 or 3/8 inch diameter bolts for mounting motors. Good luck. Ogy
 
#13
So just a 5/16x1-1/2 hex bolt should work? Does it need to be fulll thread? Or will a partly threaded work?
partially will work since you have the thickness of the engine block and engine plate to go through. Make sure and buy lock washers and flat washers for each bolt. Tighten the piss out of them and you should be ready to rock.
 

zeeman

Active Member
#15
I like to get the length as close as possible to just allow the washers and nut to fit, and I run the threads UP. That way the threads are not banging on cement, rocks etc. Makes it easier to adjust the chain if the bolts loosen easily. Just the way I do it. Other folks might not do it the same way.
 
#17
thanks guys. I will check my bolt shop out as I cant find anything i need at HomeDepot
Depot should have what you need. I also like ACE Hardware. We have a couple of great ACE stores around here. Last week the local ACE store gave me a 5/8" x 10" grade 8 bolt I needed for a new steering stem on a mini I'm building. It was prolly a $6.00 bolt, but the guy said it was an oddball and not in his system any longer and it was easier to just give it to me than mess with it in his computer.

lmfao. black or clear?...
The black ones last longer outdoors. Better UV protection. You really want them to last when they're holding the motor on. :laugh:
 
#18
ACE is the shit. we've got a really nice one a couple of minutes from where i live. i've gotten free hardware from them before as well. i'll walk up with a few nuts/bolts, the cashier looks at me and just says "have a nice day". :laugh:
 
#20
I used to use wishful thinking but it only lasts for a short time.
I like to get the length as close as possible to just allow the washers and nut to fit, and I run the threads UP. That way the threads are not banging on cement, rocks etc. Makes it easier to adjust the chain if the bolts loosen easily. Just the way I do it. Other folks might not do it the same way.
I'm right there with ZEEMAN I always try to get the shank of the bolt as close to the nut because the threads wear very fast if there is any type of stress/movement.

 
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