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Discussion Starter #1 (Edited)
I can't make a Briggs 206 horizontal OHV Intek idle

This is a nieghbor's 6.5 hp I/C intek that had a broken crankshaft.

Deal is that I will put in a new crank and then I can use the leaf vacuum that it was powering the blower for a few years ago, before it pulled up a stick into the impeller.

Changed out the crank, got it running, but only with partial choke.

This carb is very simple (LMS type). I cleaned out the bowl, the bowl retainer nut (that also functions as the main jet), and shot carb cleaner up through the two holes in the area in the middle of the circular float and got spray in the carb throat.

It is starving for fuel, but will only run with about 1/2 choke. Also will not idle down well.

Checked valve tappet clearance when I had it apart. Engine supposedly has about 50 hours on it, then was not used for 5 years or so.
 

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These carbs are really really not that good. Lots of problems with them especially when they sit up a while.

If you are positive there is nothing at all in the main jet or in the nozzel in the center of the carb, only thing you can really do, as long as you are sure the intake gaskets and insulator are installed right, with the gaskets NOT covering any vent holes or anything, is soak the carb in solvent and blow it out as best you can..if nothing changes, replace it...sadly.
 

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Discussion Starter #4
I have about 10% solution of sea foam in it, and even used sea foam's carb cleaner spray with nozzle for the blow out.

Took the carb off again, checked intake and gasket mating, making sure there are no holes being covered. Ran cleaner through the little carb's orifices again, then back togeter.

When it runs (I can get it started on the 4th pull most times), it will run with about 1/2 choke only. One click towards rich and she dies, same with one click leaner.

This means I'm totally setting the air-fuel ratio with the choke. So it is drawing fuel up through the bowl via the vaccum created by blocking the inlet to the venturi, but normal fuel travel up the passages from the bowl to the venturi (less vacuum differential but the normal operation of the carb) is not occuring at all. That could be caused by the bowl vent being blocked, but I checked it too, and even tried running the engine with the air filter cover, element, and backing plate removed also, so that the bowl vent exposure to the atmosphere can be readily seen. Not much to this carb. Stay tuned for more, maybe sitting all night with sea foam in the bowl (or all week), will make some difference.

Getting towards dark tonight, I noticed the muffler under the safety guard was glowing dull red. Is this normal, or is this poor baby too lean? Good thing there is no load on it.

I really like this OHV set up, and with adjustments to boot.

The crank was $88, the cover gasket was $4, and a new carb is $60. It also needs a new filter, being a tough life as a leaf vacuum tow behind.

A new engine is (122-032-0536B) is $210 at a dealer in Maryland.
 

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Discussion Starter #5
to update this thread-

It will run, and idle down, but won't run with less than 1/2 choke. I have even tried a trick i used on motorbikes in the old days, rev it up as much as possible and then put the palm of your hand over the intake, and flood it so quick that the debris shoots out the orifices along with fuel from the float bowl.

So now ultrasounding this tiny little non-adjustable carbeurator in a 50-50 water-simple green solution for 24 hours in my wife's jewelry cleaner. Not even the float level is adjustable. I also reset the gap between the magneto coils and the flywheel to have enough clearance for just a business card to slide between.

I like the engine. The upper end reminds me of one cylinder of a wasp radial engine that we had on display in the Santa Maria Ca. airport meseum.
 

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Discussion Starter #6
Just to update this thread, gave up on the 6.5 hp horizontal intek. When I placed a good load on it (the leaf blower turbine of the trac vac 580), it would not run up past about 1500 rpm, although it does now run with the choke set one notch off 'no choke', meaning it has 1 notch of choke.

The muffler does get dull red, even during the day.

I tore it back down to check the cam timing, governer, and exh valve decompression assy. I also took the head off, decarboned it (very little to remove) and reset the lash to specs.

Ran exactly the same, so replaced it with a new one (intek I/C with oil guard-briggs part # 122-032-0536-B8).

Can't believe how easy it starts, how guiet it runs, and how much rpm it makes loaded with the track vac turbine. Until the first oil change at 5 hours, running a bit of MMO in the gas.
 

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You should totally sell the old 6.5...
 

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Discussion Starter #8
I went back and checked cam timing (shot of this is with the sheered off crank nub showing but you get the idea) and flywheel again... it had a sheered key on the flywheel.

Explains about 10 posts and 10 hours fiddling with the LMS carb.

Also.....bought a replacement engine. Now I have a hot backup:trink40:
 

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stupid question, I know... but have you replaced the fuel line/filter/petcock?

I bought a brand new, sealed box, generator from wally world last month on a Sunday that refused to start. If it had of been any other day of the week I'd have returned it for warranty but they were closed. After several beer and some serious frustration I found a wadded up piece of paper in the 5" of fuel line going between the tank and carb.

Why was it there on a generator with 0.01 hours on the meter and an empty crank case (obvisouly new from factory)? Who knows.... but hey that was the problem.. it runs like a top now that it can drink.

Didn't notice you mention the simple stuff like plumbing.. figured I'd ask.
 

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Discussion Starter #10
My problem was that when I put it back together, the flywheel key was already damaged from the shock that broke off the PTO end of the crank, and I didn't know it. It went back together good, but on the first pull of the rope, it most likely sheared. The torque spec for the flywheel nut is 75 ft lbs, and I don't think I quite got there the first time either.

Your problem is really one for the books, almost like someone in production was up to no good. It would have been harder to find than my problem. I can tell you though, retard the timing on one of these 6.5 hp horizontal inteks, and the engine survives it, but the muffler glows like Rudolf's nose.
 
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