B&S 303777 wont run after new rings

[RevB]

I'm not exactly sure what you mean by I skipped being patient and jumping to conclusions, was I wrong to diag almost everything and then slowing cut things off until I am at one thing, the carb? My conclusion was from my diagnosis so I'm not sure what reading the manual again would do I already did that twice and there isn't really anything in there I didn't do already so I'm just confused now, you gave me a list of things which i answerd to all of them, I reset the governor like 3 or 4 times, which did nothing so I just disconnected it to have it not even be a variable, so how is that jumping to conclusions and stuff I'm just not getting this sorry

Don't pay attention to some of the "advice" you're getting. Some of these guys think they're God's gift to mechanics. Others are the real thing. You're on the right track. If some of these guys had just picked up on the fact you had a bore dial gauge and had used it to get a .0008 out of round...well, tells me you know more than it seems.

Agree with the carb. That may not be all of it but you have good compression and spark....what's left. My guess is you have access to compressed air... disassemble the carb, soak in carb cleaner or brake cleaner, blow out all the passages. Reassemble and test.

 

[highlife65]

this young man deserves all the support we can give him. Not many 17 YO's are out getting grease under their fingernails. Many young people can't get off their screens these days!
WYWY Keep up the learning work!

 

[justin@justintime]

rings is not a bad place to go on something like that but probably not the main cause. engines of that era and in genral tend to loose the oil rings and run fine on the top ring just smoke some. valves and valve clearance was most likely the true issue also common also some service bullitins and updates usually on exhaust valves. start doing your homework on valves. when i was younger I always went after rings and looking back and knowing what i know now it was rarely rings.

 

[cleverlever]

I'd bet the farm you have a restriction in the high speed jet

 

[Red Good]

From looking at your picture of the carb with the throttle plate visible , I think I would turn the idle speed screw out till there is a barely visible seam between the throttle plate and the carb body . Where it is in the pic with no load will be running faster than an idle I think .

 

[disallow]

Love reading these posts, and props to WYWY for diggin in. I'm looking for updates!

 

[zippinbye]

I'm coming in late in the game here, so apologies if this has been mentioned: fuel. Any chance it's spoiled? I have a lot of eperience with old fuel; two dozen small gas engines at a seasonal residence. I don't alway store properly. Although Stabil is an amazing crutch that keeps the neglected units running between one-year intervals. 9.9 times out of 10, an engine that requires choke to run (poorly) has bad fuel and nothing else. I'm no chemical engineer, so I cannot tie bad fuel to your high exhaust temps, except for a simple lean burn condition. Suggest a thorough fuel system purge and clean from carb to tank, and begin with some fresh gasoline. Even if this does not solve your problem, it checks-off a one item on a systematic elimination of potential issues.

 

[Rivets]

Rev, I guess you are referring to me in your post #31. I’m not Gods gift to mechanics, (far from it) but I’ve worked with teenagers repairing engines for more than a couple of years and I think I might have seen this before. Many times they want you to think they know more than you, but can’t prove it. Just because he thinks he knowns how to read a bore gage proves nothing. He took cylinder measurements, but can’t remember them, just they were good. Anyone doing this type of job knows to write things down. He didn’t have a manual so what is he using to back up his statement? He then honed the cylinder but I’ll bet he didn’t remeasure after completion. I was hoping he was one of the 5% who one day would be working on my equipment, but as I said earlier my hopes are waning. He’s in over his head and needs to rethink how he wants to proceed is up to him. I try to point people in the right direction, but refuse to do it for them. If you feel that my posts are out of line, that is your right. I for one sure hopes he proves me wrong, but seeing he hasn’t posted anything for a week, I’m not holding my breath.

 

[Auto Doc's]

This whole post went off the rails a while back. It is a 17-year-old with no experience and struggling. Yep, many of us have been there.

What was the common solution? Go back to square one, get the proper repair manual and study it.

 

[wywy]

Wow this post really took off, first sorry for not posting but I got the carb on friday night and was busy all day Saturday so I couldn't put it on, I will be doing that today I hope, RevB thank you very much for that advice, and well you geussed correctly i do have access to compressed air, I was going to do that but I thought I might as well just get a new carb it's been a very long time since I got one, Highlife thank you also for the support I appreciate that, Justin I was very skeptical on rings but I did the putting oil down the spark hole to see if it seal the rings better, yes it also could get to the valves and seal those but it turned out I was right about the rings, I think it was also valves, cleverlever I think you might be right loll, disallow thanks for that support too, zippin you are probably right I haven't changed out that fuel in about 3 months I will definitely put fresh fuel in, Rivets I'm not sure what your point is in basically saying I'm a stuck up annoying teenager, I do know how to read a dial bore gauge, i dont think i know how to, i do, but im not a 30 year experience mechanic so its a new tool i havent used before so i had to double check my measurements on it, I borrowed one from my school and my teacher showed me how to, I already knew the basic of how to read it but he just brushed me up on how to, yes I also remeasured after honing why wouldn't I? I did also follow the manual on YouTube because that was the only place I could find it, and it's starting to look like I didn't compromise any of the engine while reassmbly it was just the carb, I rebuilt this engine probably over 3 months ago so no I don't remember the exact measurements, I didn't write the measurements down because they were farrr under the limit, and also why would I work on your equipment? I'm not gonna work on some random persons equipment from them "helping me" with a mower I needed some advice for, you helped me a little bit making me recheck some stuff though so I appreciate that though, again everyone I realy appreciate the help I don't think I could've found this on my own yes its kinda dumb that it is probably just the carb but the carb was never an issue before and I never did anything with it so it just completely slipped my mind that it would've been bad, I will be putting that carb on today hopefully and I will let you guys know if it runs good I'm praying it does lol, again I don't know everything and i think i dont know as much as i should because if i did know as much as i should than i would not be here asking for advice, i messed up a diag that wouldve taken any of you like idk 10 mins to find out so yes i definitely don't know everything, I've made that pretty clear I think, but I hope this afternoon it'll run good and I will have learned to always check the carb on small engines lol