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theniteowl

Max RPM on 7HP Briggs 170701?

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theniteowl

I am trying to adjust the carb on this engine model 170701 type 0122.

I have her idling right but when I open up the throttle she sounds like she may be running way t0o fast. I cannot find any information on whether this engine has a governor or what the top RPM should be.

I adjusted the carb as per the manual I found on the Briggs site which is pretty typical stuff but it does not say anything about the top RPM the engine should be run at or how to adjust it if there is a way.

She idles fine but is not entirely smooth going from low to high throttle and backfires from the exhaust if throttled down quickly.

The exhaust stinks and she blows a bit of black smoke.

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steve-wis

Yes, there is a governor. You can download the parts manual from the Briggs site. Also, there are many posts on here on how to adjust the governor, do a search to find them. Also, make sure the spring that is around the governor rod is attached properly at both ends, this holds all the slop out of the connection. If adjusting the governor does not solve the problem, I would start the engine, run it at a fast idle, then with your finger push the governor arm a bit in each direction and see if there is resistance and if it returns to the original position. If it doesn't, you may have internal damage to the governor assembly. Pretty sure the top rpm should be around 3600.

Steve

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TimJr

This is easier to show than explain. 3600RPM should be right on a typical 7hp Briggs. With the engine off, loosen up the governor arm where it is clamped to the governor shaft where it comes out the side of the engine. Without an engine in front of me, you will have to check this yourself. Figure which way the shaft rotates when the carb is put at full throttle. I think it will be clockwise. Hold the lever at full throttle and rotate the shaft with a pair of pliers all the way in the SAME direction. This takes out any slop in the internal parts. This does not set the actual speed - the spring itself and the hole it is in sets the speed. Also, the tab on the linkage that the governor spring hooks to is the adjustment - just bend it. Pulling the spring more will raise the RPM, shortening the pull on the spring will lower RPM. On any small engine, if the governor works, you would be able to walk up to the engine while it is running at any speed and cut the governor spring right off. The engine should just go down to the low idle and stay there.

The basic adjustment on a typical Briggs carb adjustable needle is 1.5 turns out from lightly seated. A 7hp Briggs could have 2 different style carbs - if you post a pic I can tell you which screw is for low idle mixture and which is for high idle mixture. Obviously a worn engine, dirty carb or vacuum leaks would cause you to adjust a carb way off from the 1.5 turns out. If you are say 3 turns out or barely opened up off seated, something else is out of whack and should be looked into.

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theniteowl

It looks like the governor assembly is missing from the engine entirely.

It was hard to figure out from the parts catalog drawings where it should be on the engine or even which version it should be but it appears it should be below and right of the carb? This sucks as now I have to find a governor that will fit before I can safely run this engine. I have a couple of old 6hp engines, I will have to look and see if the governors will fit.

Thanks for the info. Now I have to search for parts. I was hoping to get the engine broken in before the temps got too cold.

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theniteowl

The Briggs manual makes it very hard to determine which governor parts are for my engine. I still have to dig out the 6hp engines to see what they have but the carb on this engine looks like one for a 9 or 10hp. I can't upload a picture from my phone fit some reason so will have to send it when I get home.

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theniteowl

My problem is that there does not seem to be any governor controls on the outside of the engine.

I do not know what it is supposed to look like on this engine. The Briggs manual shows several variations and I have not been able to identify which is for my engine.

If someone with one of these older engines can post a picture of their govenor setup it would help a lot.

There is no governor plate to connect the throttle to, the entire assembly is missing.

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dhoadley

Trent, I'm tearing into 3 of these engines now. Here are some photos from the cleanest one.

P1100885.JPG

P1100886.JPG

P1100887.JPG

This is on the carb side of the engine. That rod with the spring attaches to the carb. Dave

P1100885.JPG.a9804f46c6dfe71f32dce0ef48ab7e57.JPG

P1100886.JPG.e3ddf61c38712c33816310b3c2766393.JPG

P1100887.JPG.3e1d2cc28e584f13453e391adf3774f4.JPG

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theniteowl

BLT, thanks for the link to that other manual, it contains much more detail and better diagrams. I still could not identify which governor control I needed from it though. Matching by the carb type lead me to believe it was one governor plate type but that ends up clashing with the photos dhoadley has posted. There are so many variations for these engines that if you do not have the original parts to compare to it is difficult to determine what is missing.

That manual has far more detail for everything about these engines though.

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theniteowl

Thanks dhoadley, that helps a lot.

Are those 7hp engines? Looking up the part number for that style plate it looks like it is used on some 10hp engines as well as the 7.

Are the carbs for these the two piece with the bracket along the bottom holdng them together? Which side of the carb does the choke connect to inside or outside?

The picture does not show a rod from the governor control plate to the choke on the carb, does the choke cable go there directly? There does not seem to be anyplace to attach the choke cable on my carb so if you can give me any info on how that hooks up I would greatly appreciate it.

Thanks for the pictures.

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dhoadley

These seem to be 7 or 8 hp engines, certainly not 10. The carbs are one piece with 2 plates; the choke plate is "up-stream" near the air cleaner with the tiny control arm on the outside and then about in the middle is a 2nd plate that the governor-rod connects to with the tiny control arm on the inside. The carburetors are in the garage at my other house or I would post a pic. Can do that this weekend.

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theniteowl

I found the governor control plate and the rods to connect it to the carb on eBay. They list that plate for 10 HP engines but it is the same number as the 7 and 8 HP.

I need to find whatever I need to connect the choke cable to the carb.

I have two old Broadmoor 6 HP engines but neither had the governor plate on the engines and I have only found one of the carbs which did not have any way to mount the choke cable. One of them was connected on the tractor when I got it several years ago but I do not recall how or if it was even connected properly.

Thanks.

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theniteowl

The plate shown in your pictures did not fit my engine. I do not have the mounting hole on the upper left to attach it. I found the other type paste and it fits correctly. I got everything hooked up but still have issues with the RPM running too high even after adjusting the governor arm. I suspect a problem with the governor inside the engine and may have to pull the engine to check it out.

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theniteowl

I pulled the engine, opened it up and found the oil slinger was in pieces. The bottom oil seal had a very slight leak as well so this engine was not fully rebuilt although the cross hatching in the cylinder is still nice and visible so it at least had the cylinder honed and new rings.

I have parts on the way so perhaps by next weekend I will have her running properly.

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theniteowl

When I turned the engine over to remove the pan I heard a clink as a piece fell. When I opened it I found this.

20160118_175347.jpg

The rest of the pieces were lying down in the block.I cleaned out the pieces and everything else looks fine. Just waiting on a new oil slinger to arrive so I can put it back together.

20160118_175347.jpg.3f03cd2a0b0b5896a37f545bd7953886.jpg

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