Individual Pod Filters - learned something new

[Hooligan]

I know this has been a hot topic of conversation for years but I just learned something quite interesting on the subject. In my case I am using the full foam Uni Filters, with no hard end, to prevent pressure wave reflection.

On the motor my LC came with (built by Solo2) I could never get the carbonation just right. The motor just didn't like 100% throttle. It was fine at 90% throttle but would bog if I gave it the last 10%. As this is my tinkering about street bike and essentially never gets used at 100% throttle this wasn't that big of a deal.

Over the winter I built up a complete second motor that has its own intake system and carbs. I set up the jetting same as on motor #1. Upon first ride I discovered much to my amazement that motor #2 has no issues with 100% throttle and pulls beautifully throughout the rev range. It almost seems a bit stronger than motor #1.

AFAIK the two motors are more or less the same. They likely have slightly different bores and I'm not sure what exact pistons Solo used in the build. Both motors use the same pipes and the same Uni filters. Both are O-ringed head with CF reeds and 6mm reed spacers.

Thus, the thing I learned is that it is entirely possible to jet a motor to run just fine w foam pod filters. Now I just need to figure out what the difference is between my two motors so I can get #1 to work as well as #2.

FWIW the reason I went to the pod filters is that the 6mm reed block spacers make getting the carbs in and out a serious PIA. The job is 100x easier with the pod filters.

[Bare]

IF.. your info under your name is current ? then it's the OEM pipes.
Those are Crap. Not putting too fine a point on it.
Remember that Stock LC's output a whopping 37 hp (not the Yama BS claim of 47 hp)
Their exhausts were sized appropriately.

[Hooligan]

I am still running the OEM pipes.

But that doesn't explain why #2 motor/carbs runs fine w the pods and #1 motor/carbs does not.

One of these days I will get a decent set of spannies but not right now.

[T.RexRacing]

Reeds?

[kpke]

Hooligan, I posted somewhere on the forum where I replaced hard backed pods with full foam on my thrasher bike.

What a difference it made. It got rid of a midrange sputter and made the bike a little funner to ride. Even at 100% throttle.

Your situation is interesting with both engines running full foam pods. Maybe T.Rex got it, different reeds???

Glad to hear your bike is running good.

[T.RexRacing]

Yeah I wouldn't worry too much about why. Time to go riding.

[evan_calgary]

Suppose just proof that different motors like different things. Have always heard it before but haven't owned enough of the same bike to see it.
Glad to hear you are out and riding Peter!

[Hooligan]

Reeds?

Nope. I tried as much as possible to make the two engines the same. Both are running 6mm reed block spacers and both have same make of CF reeds.

Yeah I wouldn't worry too much about why. Time to go riding.

Not worried, just interested to note the difference.

Suppose just proof that different motors like different things. Have always heard it before but haven't owned enough of the same bike to see it.
Glad to hear you are out and riding Peter!

It would be interesting to work out why though. I guess with a 2-stroke being a big air pressure tuning fork, minor alterations can make big differences.

If you are interested, we are going out Fri eve just to enjoy the good weather. Prob gonna head downtown to get some dinner.

[T.RexRacing]

Are they both running in different bikes? I'd ride 'em for a few thousand and dyno them side by side just to know.

[Hooligan]

Are they both running in different bikes? I'd ride 'em for a few thousand and dyno them side by side just to know.

No. I have two motors for one bike.

The plan is to run one motor for 2 years, then swap and run the other for 2 years. That way I always have a spare motor ready to go in the event I grenade one and the spare doesn't sit forever without ever getting used.

[T.RexRacing]

Well if ya ever get down to West Virginia I could slot you some dyno time.

[hondaror]

Peter, have you had the Solo engine apart? I'm wondering about possible porting differences. Did you use the same reeds in both or a different set of the same type? There could be a difference there too. Things to ponder.

[Hooligan]

I've had the head off engine #1 but never really looked at the porting. Each engine has a complete induction system of its own including its own set of carbs. I filed the reed cages on both and both are running the same make/model of reeds.

[seahorse]

Variables in timing position.
Carb balancing.
Float level heights.
Main jet sizes.
Oil pump setting.
Air settings.
Slide wear in the carbs.
Their are quite a few variables as to why one bike could be tuned slightly different to the other. Besides porting reeds and squish volume. PS if the piston crowns are different then that may be your answer right there.
I now vac balance my two stroke carbs, and there is a difference in how they perform.
Hard backed short pods will choke a bike, I proved this running back to back tests on the 421. The longer the filter the better the bike performed. We have discussed maximising still Air Volume in the past, hence why air boxes work so well.
Something for Bare to chew on.

[Hooligan]

The pod filters I am running look exactly like this. They are full foam with no hard parts.