94ss dyno cam

[freshness]

I bought a new 94ss dyno cam I need some help getting the motor to run smoothly with the more aggressive cam has anybody had any experience using this cam any help would be great

 

[KartFab]

Please describe your problem. I'm assuming you put it on a Briggs 5 hp flathead. The cam would not be the source of an engine running rough. Look up the cam card and:

1) make sure your valve lash is set to what it specifies on the cam card
2) make sure timing is set to what it specifies on the cam card
3) high flow intake and exhaust?
4) jetted correctly?
5) dot on cam lines up with dot on crank?

 

[bob58o]

what other work has been done? What engine? What size springs? Intake? Exhaust? Jets? Carb? Flywheel timing? Fuel pump? Be more specific as to what's not smooth.

Somebody might be able to help if you give a lil mo info. I'm just installing a Black Mamba Jr and bunch of new stuff so I've been researching but have no experience.

Did you get new valves as suggested on the Dyno site?

---------- Post added at 04:55 PM ---------- Previous post was at 04:48 PM ----------

Here's a link to the cam
http://www.dynocams.com/item/94ss/

---------- Post added at 04:56 PM ---------- Previous post was at 04:55 PM ----------

DESCRIPTION
This is our #1 selling Hot Stock cheater cam. It does not require any type of machine work to install. Billet lifters are not required, but new valves are needed to achieve proper valve lash.
The lobes are hardened for extra durability, extending the life of this cam.

SPECS
Engine: Briggs 5HP Flathead
Recommended Class: Hot Stock
Target (MAX) RPM: 7000
Spring Pressure (In / Ex): 20 lbs
Valve Lash (In/Ex): .005" / .006"
Ignition Timining: 30-32 Deg BTDC

 

[bob58o]

Please describe your problem. I'm assuming you put it on a Briggs 5 hp flathead. The cam would not be the source of an engine running rough. Look up the cam card and:

1) make sure your valve lash is set to what it specifies on the cam card
2) make sure timing is set to what it specifies on the cam card
3) high flow intake and exhaust?
4) jetted correctly?
5) dot on cam lines up with dot on crank?

Jinx

 

[freshness]

i have done a small amount of porting and polishing probably could use more I have shaved the eyebrows down I lashed the valves no carb work to the stock carb did not get new valves either or springs does have a billet rod as far as I can tell the dots line up on crank and cam im still kinda new to all this there is a guy in my shop that knows more than I do but he wont give up any help cause im racing against him I haven't messed with this much lately cause its now just getting warm out but tryin to bring a worthy cart to the track

---------- Post added at 12:12 PM ---------- Previous post was at 12:09 PM ----------

after installing the new cam its hard to get started when it does start it will run pretty high then die out then its a bear to start again even when I hit the butterfly to keep it from dyin it still goes down so that's where im at with it now

---------- Post added at 12:19 PM ---------- Previous post was at 12:12 PM ----------

I did remove stock muffler and straight piped it I do have a high flow three stage header on order right now if the makes a difference vs. the straight pipe I know the stock muff is very restrictive

 

[bob58o]

Somebody with more experience should help...Did you change air filter?

I had to advance flywheel to get to 32 degrees.

I had to make carb main jet bigger when changing exhaust and intake.

I had to change valve springs when installing cam....

ALL on a different OHV engine

---------- Post added at 01:51 PM ---------- Previous post was at 01:45 PM ----------

Perhaps start with ignition timing, then jets, then springs..??
Check spark plug reading to see if running lean?

 

[freshness]

what degree timing key did you use to advance the flywheel

how much bigger did you re-jet the main carb jet

I will order some 20lb spring then too

the other guy I know has an aftermarket cam and he used a 6 degree key

 

[bob58o]

what degree timing key did you use to advance the flywheel

how much bigger did you re-jet the main carb jet

I will order some 20lb spring then too

the other guy I know has an aftermarket cam and he used a 6 degree key

The woodruff key that came with the kit I bought is an 8 degree key. I think my engine came stock around 24 degrees, but never learned how to make/use degree wheel and don't have or know how to use timing light thing. Mind you, I have a different type of engine.

The kit I purchased came with 0.0037" and 0.0038" main jet options for the Rui X ing Carb. I didn't have to drill the stock one, but I think you can. For example, I think drill bits around #60 -#65 are in the 0.035" to 0.040" range.

If you can open up the throttle for a minute or so and kill it at higher rpm (3600 - 4000?), then check the spark plug. Too black means to rich (not enough air or main jet too big). Too white means to lean (too much air or main jet too small). I'd only try 1 drill size at a time and test and read spark plug again.

Lash is set properly according to the Cam card. 0.005" and 0.006". It says stock valves can't be set to this???????

What does the air intake look like?

---------- Post added at 04:16 PM ---------- Previous post was at 04:12 PM ----------

You'd have to put it on youtube or something, but a video of you starting it might help.
Showing how you have to use the choke and throttle.

 

[freshness]

not sure what you mean by the air intake?
I need to get an air filter cause this motor came off of a snowblower
i do have other briggs motors that i use but this one im trying to beef up so i can beat the other guy i do know some about these motors just not a lot on what and how to do some of these other mods i appreciate all the help you have given me so far im going to work on these issues in the coming day and i will update as i progress thanks again
anything else you can think of would be great

 

[bob58o]

not sure what you mean by the air intake?
I need to get an air filter cause this motor came off of a snowblower

Sorry, are you using the stock air box? Or did you upgrade to a more free flowing air filter when you upgraded the exhaust?

 

[freshness]

i did not up grade air filter it didn't have one when i got the motor so i have been runnin no air filter thus far will putting an air filter on improve performance i have been meaning to get one just got put on the back burner

 

[bob58o]

I have never tried running with no air filter. Ultra High flow, but dirty engine??? I have an adapter to use an tapered cone style (like K&N) air filter.


All this being said... I still don't know what the problem is... And am not saying any of this will fix your exact issue, but if it were me... These are the things, I'd try.

I have never had to trouble shoot something like this, sorry

---------- Post added at 05:16 PM ---------- Previous post was at 04:58 PM ----------

BTW... with no air cleaner you probably, need to clean the carb... Youtube how to do that. That might be the main issue??

---------- Post added at 05:19 PM ---------- Previous post was at 05:16 PM ----------

Also I keep assuming the valve lash was able to be set correctly even with the stock valves, even though the cam description says otherwise?????

 

[KartFab]

My thoughts.

1) you are running lean. Governor removed I assume.
2) get the arc billet flywheel from OMB warehouse for the 5 hp flathead. It is already set at 30 deg btdc.
3) Briggs have a problem with fuel delivery on cold starts (long straw). There are these little accordion pump things that fit over the gas cap to shove fuel up the straw for easier starts. If the straw is cracked, or you have bad diaphragm or partially clogged jet, that could also be an issue, but I'm betting you are just needing to rejet like bob pointed out.

 

[chancer]

Note to BOB...
I think you are talking about your Predator and he is doing A Briggs Flathead.
Not that your Totally out of line, just there are some drastic differences.

 

[bob58o]

Note to BOB...
I think you are talking about your Predator and he is doing A Briggs Flathead.
Not that your Totally out of line, just there are some drastic differences.

I pointed that out already... But thought all the info still applied.