Stock valves in 6.5 hp Clone

[MaxSpeed]

I recently ordered several parts for my 6.5 hp Clone. My intentions are to make a decent amount of power and still have a reliable engine. I also plan to stay with the stock rocker arms. Is it necessary to upgrade the stock valves and push rods to stainless steel valves and chrome molly push rods? Take a look at my parts list and render your opinions.

Arc Rod, Honda aluminum flywheel, Flat top piston, Ring set, .265 modified cam, 18# springs, Aluminum retainer/keeper set, 10.9 bolt/stud kit, and a ProMod j/s kit (still need to know which gearing and clutch is best for a 160# rider to run wide open in the 1/8 mile)?

Keep in mind I have already cleaned up and smoothed the stock head ports. I am still up in the air about which carburetor to buy.

 

[Strigoi]

i'd get a carb before worrying about the valves. that cam won't be doing much good with the stock carb. do you have a header on the engine?

 

[jesse8931]

if your gonna buy the honda flywheel just grab an arc billet flywheel

 

[MaxSpeed]

i'd get a carb before worrying about the valves. that cam won't be doing much good with the stock carb. do you have a header on the engine?

I am leaning towards the 22mm Mikuni carb, but will also replace the valves and push rods if there's some benefit from changing them. I also don't have a header yet. I am waiting to see what AGK's DB header will look like before make a decision on the exhaust. I have been talking with Shane via e-mail and he told me that AGK should have the new DB header ready within the next week. He also said that AGK's website will soon be updated to include a mini bike section, as they plan to develop and offer performance parts for mini bikes.

 

[MaxSpeed]

if your gonna buy the honda flywheel just grab an arc billet flywheel

I decided to go with the Honda flywheel because it already has 4 degrees of timing advance built in. I also didn't want to risk shearing off a timing key with the ARC flywheel. I have also read that the Honda flywheel can withstand upwards of 7000 rpm with no problem. The ARC flywheel is definitely a nicer looking piece though.

 

[Strigoi]

I also don't have a header yet. I am waiting to see what AGK's DB header will look like before make a decision on the exhaust.

do a header and carb before messing with the valve train. the rest of your mods aren't really doing you any good with the stock carb/exhaust on it. the carb/header/gov removal/billet rod/18lb springs should be the first mods done to an engine.

I decided to go with the Honda flywheel because it already has 4 degrees of timing advance built in. I also didn't want to risk shearing off a timing key with the ARC flywheel. I have also read that the Honda flywheel can withstand upwards of 7000 rpm with no problem. The ARC flywheel is definitely a nicer looking piece though.

the ARC flywheel is SFI approved and i believe it's good to 10k rpm or so (might be wrong on that though).

 

[Solo Cali]

I decided to go with the Honda flywheel because it already has 4 degrees of timing advance built in. I also didn't want to risk shearing off a timing key with the ARC flywheel. I have also read that the Honda flywheel can withstand upwards of 7000 rpm with no problem. The ARC flywheel is definitely a nicer looking piece though.

Who told you they were only good up to 7k ?

 

[TT]

At the risk of disturbing the peace;

Arc billet flywheel with 8 degrees of timing.
Have the head work done for you and get the SS oversize valves and cromolly push rods.
Buy a RLV header from AGK.
Get a 22 MM Mikuni Kit complete intake to foam air filter.
275 or larger camshaft
(Or simply leave the HF motor stock. Gov. in place and go). :hammer: :doah: :smile:

Modifications does not reduce reliability if its built right. Mine reved to 9830 rpm no load and it still runs like a champ.

Listen bubba, power and stock are two different feelings.

TT Out~

 

[MaxSpeed]

Who told you they were only good up to 7k ?

What I should have said was; I have read the Honda aluminum flywheel can exceed 7K rpm without issues.

http://www.oldminibikes.com/forum/h...wheel-6-5-clone.html?highlight=honda+flywheel

 

[edwin]

max speed, you also mentioned in your first post a pro mod jackshaft kit. i thought those were only for the 2.8 stock engines. are you putting one of those kits on your 6.5 ?

 

[MaxSpeed]

max speed, you also mentioned in your first post a pro mod jackshaft kit. i thought those were only for the 2.8 stock engines. are you putting one of those kits on your 6.5 ?

Yes, I have talked with Brad at ProMod and he said that his j/s kit will work on the 6.5 too. All I would need to do is change the j/s gearing, order the engine mount plate, and a spacer for the clutch (all of which he sells).

 

[edwin]

Yes, I have talked with Brad at ProMod and he said that his j/s kit will work on the 6.5 too. All I would need to do is change the j/s gearing, order the engine mount plate, and a spacer for the clutch (all of which he sells).

thats awesome. lets see it when you get it hooked up. im curious thanks

 

[olajoe808]

What I should have said was; I have read the Honda aluminum flywheel can exceed 7K rpm without issues....

yea it's been posted by long time builders spinning them regularly at 7k. Still there are others having raced em at 9k+. Here's one that turns within that range-wheels on the ground. The engine does get opened up every couple hours of ride time for inspections and it seems to be holding together well. However, if you have any concerns about the stock flywheel or any flywheel for that matter a tach can help. About 1/2 the price of a HP flywheel, comes in real handy for tuning, and it'll show you the redline every time...