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Mod | | | Forums66 Topics128,014 Posts1,055,328 Members48,419 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Feb 2000 Posts: 69 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 69 | The book say to set the timing so that the pointer is on the ball; is this correct? On my newly rebuilt engine I'm getting a lot of popping in the muffler, especially when cold. I've changed three carburetors but it doesn't seem to change this. What could it be? Are my valve springs weak, or is the timing off. I set the valves to .006 and .20 like it says. | | | | | Joined: Jan 2000 Posts: 2,074 'Bolter | | 'Bolter Joined: Jan 2000 Posts: 2,074 | You could try to advance the timing a bit. I like to use a vacuum gauge and set the dist at peak vacuum. Also the vacuun gauge is a great diagnostic tool, for checking valve adjust etc. Best of luck Jim Turlock P.S. Love the suburban, had the pickup to match but sold it like a fool. | | | | | Joined: Feb 2000 Posts: 69 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 69 | Yeah Jim, I know the feeling, but someing else always comes along. I'll try the vacuum gauge but still wondering why the missing and poping in the muffler. Runs fine out on the road. ron brazell vallejo ca | | | | | Joined: Jan 2000 Posts: 2,074 'Bolter | | 'Bolter Joined: Jan 2000 Posts: 2,074 | An old friend of mine showed me a trick, with the car running hold a piece of paper up to the exhaust pipe as a quick check for a miss.
You still could need to re-adjust the valves or have a vacuum leak, carb problem etc. Also a compression test is an important first step of a good tune up. Be sure your valve adjust is with the motor fully warmed up, like 20 minutes. | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | What year 261?
What year flywheel do you have on your engine?
What year clutch housing do you have on your engine?
Have you checked the float carburetor setting?
| | | | | Joined: Feb 2000 Posts: 69 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 69 | I'll try changing the distributor tomorrow and see if that changes anything. | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | uncleb,
If you get a vacuum gauge for diagnostics, set the carb with the vacuum gauge (maximum vacuum at the idle setting) and set the timing with the vacuum gauge (rotate distributor for maximum vacuum). It's worth a try.
Good luck, Tim | | | | | Joined: May 2004 Posts: 920 'Bolter | | 'Bolter Joined: May 2004 Posts: 920 | Mine did that when I forgot to put gaskets between the spacer and the carb/intake. | | | | | Joined: Oct 2001 Posts: 3,458 Extreme Gabster | | Extreme Gabster Joined: Oct 2001 Posts: 3,458 | Are you using the 261's flywheel or the original 216 flywheel? The balls aren't in the same spot between the two. Popping can also be a sign of poor dwell, check the point gap or measure the dwell with a meter.
Paint & Body Shop moderator A lone amateur built the Ark. A large group of professionals built the Titanic. | | | | | Joined: Feb 2000 Posts: 69 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 69 | Hmmmmmmm....., now I don't know if I did use the 261 flywheel, I'll do some comparing, excellent point. | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | As also asked earlier, what clutch housing (bell housing) are you using? Is it possible (4ontheFloor, others?) that the pointer might be located differently on certain truck/auto early/late 216/235/261 clutch housings)? If you set the timing with a vacuum gauge, the location of the ball, pointer, and type-of-marking on flywheel will not matter. I prefer a timing light but the vacuum method also seems to work OK. Tim | | | | | Joined: Feb 2000 Posts: 69 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 69 | Good advice, I'll use the vacuum gauge, then mark the flywheel. Thanks Tim. | | | | | | Dave Giorgi Unregistered | | Dave Giorgi Unregistered | As JIMERIT said..." the first and most important step of a tune up is to check the compression". Start there that way yo'll know if its a valve problem.
Dave | | |
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