need help [classic clogged carb - Ed.]

[reynoldston]

You are right the air filter and air leaks will affect the runing of that small engine big time. I know because I tryed to run mine without the air filter and it didn''t run very good.

[spree1]

yes i dont have the filter installed. should i put it together? should it run normally either way

[Bear45-70]

yes i dont have the filter installed. should i put it together? should it run normally either way

You are lucky it started at all without the air filter. No, it will not run right without the air filter in place. Honda designed this engine from the air box opening to the tip of the exhaust as a system. Remove or change any one part and it ain't gonna work right anymore.

[reynoldston]

It looks like your problim is found, Bear 45/70 is right on this.

[Trafficjamz]

yes i dont have the filter installed. should i put it together? should it run normally either way

You are lucky it started at all without the air filter. No, it will not run right without the air filter in place. Honda designed this engine from the air box opening to the tip of the exhaust as a system. Remove or change any one part and it ain't gonna work right anymore.

I don't usually have trouble getting a spree with no air box to start or idle.........It will seem fine, until I actually try to drive it.

Then it does exactly what the OP is describing.

Put your stock air box on, and make sure the lid is on tight.

[noiseguy]

This is the second most common running issue with Spree (not running past idle without the air filter in place), besides blocked idle jets.

Odd, b/c the Elite's don't have a problem with this at all. Would love someone to give me a definitive reason why this is.

[Wheelman-111]

Greetings:

Noisy Axt:

Odd, b/c the Elite's don't have a problem with this at all. Would love someone to give me a definitive reason why this is.

I bet if you could measure the Pilot hole cast into the Spree's carb, you'd find it a whole lot smaller than the PA series carbs adorning the SE/05 and SA16 items. Unfortunately nobody has indexing wire that thin...

[Trafficjamz]

This is the second most common running issue with Spree (not running past idle without the air filter in place), besides blocked idle jets.

Odd, b/c the Elite's don't have a problem with this at all. Would love someone to give me a definitive reason why this is.

A spree with no air box can rev up just fine on the center stand. Why......because there is no load on the engine.

The elite S has a variator. The starting ratio in an elite is like 30:1, and then starting(and only) ratio of a spree is about 11:1

That is why.

[noiseguy]

Agree that Spree is not making any power without the element, but will spin up, which is why it will rev on the stand, but won't go once on its wheels.

But the Elite makes more than adequate power, and it's not just gearing. My 1 data point is an '87 SE50 I rebuilt. Pod filter, OEM box, no filter, ran the same with more or less the same top speed. Same top speed = same overall peak power. And really no slower getting there.

I don't think it's the idle jet size either... size there wouldn't make a difference on WOT running.

I think it's a matter of lengths in the intake tract, from the carb to the cylinder.

Note that Spree has a long intake tube (~4"); as long as *thats* in place the Spree will run fine (I built a pod filter on one of these tubes and it ran great.) Bet it would run great with any 4" tube stuffed over the back, in fact.

The Elite, by comparison, is very short; the distance from the carb face to the open box is nothing (~1").

Perhaps because the Spree is unvariated (shorter distance from reeds to cylinder) and has a fairly short manifold, it needs the extra length at the back of the carb to tune it properly at its operating RPMS (~8000). As I recall from engine design, the tuning of the intake tract is based on its overall length, and the peakiness of the tune is a function of where the carb sits on that length. Sitting right in the center would be the peaky-est, at the frequency/RPM of the length's 1/2 wave. That intake tube makes up the last bit of length it needs.

What gives me pause is that lots of 2T designs have short intake tracts and run fine. This one doesn't. So I think I'm missing something.

[spree1]

i put the air filter assy. back together and put it on. it is still not accelerating right. it still sputters after it gets up to around 15 mph. so what do you think is the problem? it smokes to. i adjusted the air/fuel screw it helped a little.

[spree-rider]

check the air filtert to inside the airbox.

[spree1]

i did its clean. how do i check the timing on this bike. i know i need a timing gun. do i hook it up like i would a car?

[spree-rider]

the timing is fine.

[martynkim]

No timing. Check for air leaks between the carb and filter or the box itself. Or the carb is still dirty.

[Wheelman-111]

Greetings:

Spark Timing is determined by a pickup coil wedged in the crankcase and the flywheel. The only way it can change is by rotating the flywheel. Because of the Woodruff Key, that's hard to do - at least accurately.

If the flywheel was incorrectly installed, it can spin on the shaft and throw off the timing. The Factory Manual outlines the steps to check timing, but I bet it's still the intake/carb issue.

Symptoms sound like a clogged Pilot.