CB77 305 Cold Cylinders

[65hawkchopper]

Hi folks;

I am not one to join forums just to pimp for information, but I am at a dilemma here and ask some assistance. I had purchased a 1965 CB77 Superhawk a few months ago. It (Supposedly) sat and wasn't run for 25+ years. I had got it running 2 hours after I got it home. Did all the preliminaries. Changed oil, cleaned carbs, cleaned/set points, etc, etc. Fired it up and one cylinder (Right) ran cool/cold compared to the other. It did fire, but as I say it was cool. 40-80+ degrees cooler. I had done all the diagnostics (Without getting on a soapbox, I add that I am an automotive/diesel mechanic of 30 years and am ASE certified in both gas and Diesel engines.) for compression, spark, and cylinder leakdown. Right cylinder was weak. Tore upper motor down and found #2 rings were upside-down, right cylinder had 1 broken ring as well as being siezed in the groove with (Extreme) carbon. Cleaned everything and installed new rings in both cylinders along with rehoning cylinders. (Everything speced {Mechanically/physically} out OK according to Bill Silvers Restoration guides.) When I fire it up the right cylinder is still cool/cold compared to the left. HOWEVER; (And this is what realy puzzles me!) When the right cylinder fires, the left gets cool! And Visa-versa. But for the most part, the right cylinder stays cool. I have installed new points and plugs also. I took Ohm readings on the coils and condensors, and they all had the same reading as pairs. But I do not know what those specs are. I show no shorts/grounds between primary and secondary fields on the coils, and no shorts/grounds on the condensors. I even swapped coils/condensors between cylinders and have the same results, so I assume all ignition components are OK. I just reset the carb needles to Bill Silvers recomendations (Clip on the 2nd notch, was at 5th) but havn't fired it up yet. The only thing I can think of is an ignition problem. BUT WHERE! Could my condensors be shorting across each other and bogarting energy? Has anyone else out there experienced this? If so could you lend a hand? Thanks.

[G-Man]

I'm sure that rescuers will arrive soon but you didn't mention whether you had checked plug leads / caps. One of the recommendations I hear a lot here is to trim back 1/4 inch of the plug lead are reinstall the cap to get a better connection.

You also may need to check the carbs again in case you have some dirt in the tank etc. Odd that it changes right / left as you say. Do you have a fresh, well-charged battery?

Good luck!

G

[LOUD MOUSE]

Go to the FAQ Left/Yellow then to How I Tune My Engine. ......................lm

Hi folks;

I am not one to join forums just to pimp for information, but I am at a dilemma here and ask some assistance. I had purchased a 1965 CB77 Superhawk a few months ago. It (Supposedly) sat and wasn't run for 25+ years. I had got it running 2 hours after I got it home. Did all the preliminaries. Changed oil, cleaned carbs, cleaned/set points, etc, etc. Fired it up and one cylinder (Right) ran cool/cold compared to the other. It did fire, but as I say it was cool. 40-80+ degrees cooler. I had done all the diagnostics (Without getting on a soapbox, I add that I am an automotive/diesel mechanic of 30 years and am ASE certified in both gas and Diesel engines.) for compression, spark, and cylinder leakdown. Right cylinder was weak. Tore upper motor down and found #2 rings were upside-down, right cylinder had 1 broken ring as well as being siezed in the groove with (Extreme) carbon. Cleaned everything and installed new rings in both cylinders along with rehoning cylinders. (Everything speced {Mechanically/physically} out OK according to Bill Silvers Restoration guides.) When I fire it up the right cylinder is still cool/cold compared to the left. HOWEVER; (And this is what realy puzzles me!) When the right cylinder fires, the left gets cool! And Visa-versa. But for the most part, the right cylinder stays cool. I have installed new points and plugs also. I took Ohm readings on the coils and condensors, and they all had the same reading as pairs. But I do not know what those specs are. I show no shorts/grounds between primary and secondary fields on the coils, and no shorts/grounds on the condensors. I even swapped coils/condensors between cylinders and have the same results, so I assume all ignition components are OK. I just reset the carb needles to Bill Silvers recomendations (Clip on the 2nd notch, was at 5th) but havn't fired it up yet. The only thing I can think of is an ignition problem. BUT WHERE! Could my condensors be shorting across each other and bogarting energy? Has anyone else out there experienced this? If so could you lend a hand? Thanks.

[Hotshoe]

Fired it up and one cylinder (Right) ran cool/cold compared to the other. It did fire, but as I say it was cool. 40-80+ degrees cooler.
When I fire it up the right cylinder is still cool/cold compared to the left. HOWEVER; (And this is what realy puzzles me!) When the right cylinder fires, the left gets cool! And Visa-versa. But for the most part, the right cylinder stays cool.

-------------------------------------------

Reading your post brings up a few questions;
How are you getting a cylinder temp reading?
How long did you run it to get the temp reading?
Have you looked at the plugs color after running a few minutes?
When you talk about the right cylinder firing and left getting cool etc, are you talking about spark at the plug or an actual temp reading?
My first impression is that it's got malaria..... kidding, sounds kinda pointsy to me.
Check the wires from the condensers to the points.
They attach to the points with machine screws and fiber insulator washers that have to be stacked properly.

[65hawkchopper]

Loudmouse and hotshoe; Thanks for your input. Sorry I took so long to reply, but here it is. After all I first posted, I decided to pull the mill and remove the head to check out the gaskets and cylinders. Here's what I found: Gaskets were OK. Whoever last was inside this had put the #2 rings in upside down. Right cylinder/rings were so carboned up that #2 was siezed in piston groove, and #1 ring was broken. Further found that ring end gaps in both cylinders (And I'm not kidding here.) were at least 1/8 inch. I cleaned all the ring grooves and installed all new rings. Miced/honed cylinders and reassembled with new gaskets per the manual specs. Put the mill back in the frame and fired it up. Ran great on both cylinders for about 3 minutes and then I'll be da#*ed if the right cylinder didn't go cold again. (Hotshoe, I take my temp readings with a reyvac thermo sensor about 4 inches (away) from the first bend in the exhaust pipes. Before cylinder went cold, both cylinders were within 20 degrees of each other. Figured, great, now all I had to do was fine-tune the carbs. WRONG! Right cylinder did not kick back in. Out of answers, I pulled the NEW DH8A plugs and reinstalled the original D8H S plugs that were in it. Low and behold, both cylinders were once again firing within 20 degrees (Temp) of each other. Being that the D8H plugs are no longer available, (I considered going with a hotter plug too.) and I didn't want to spend 6 bux a pop on ebay, I ordered the D8H S plugs through work (Only paid $1.25 ea) and put them in. Ran for AT LEAST 25 minutes with box fan in front of motor and both cylinders kept close temps and neither went cold. Pipes were between 230 and 260 degrees. Next time I fire up, I'm making a note to shoot at the cylinders and see what readings I get there. What numbers should I be looking for? I'm guessing not much more than 180-200 degrees. Maybe 220 TOPS! I also have to address the fine tuning of the carbs. Based on what I am about to write can you give me your input? It's still running (REALLY) rich, but not as bad as when I first got it running. Ignition timing is set per EdMoore's Tuning Recipe, and marks are right on. Carbs have been thuroughly cleaned/boiled and dried. Also set (Preliminary setting) according to ED's recipe. According to Bill Silvers restoration guide tune up proceedure; One should advance timing closer to the "T" mark if advance marks are exceeded around 3300 rpms. Would it help (OR would it hurt?) If I retarded the timing (Away from the "F" mark but between the advance marks.) to give the cylinders more burn time as long as the advance marks aren't passed at the 3000 rpm range? The way I read the marks is that the "F" fire mark is only about 4-6 degrees before TDC. (The "T" mark) IF that. What do you guys think? Forgot to mention that I assured that cam and crank were POSITIVELY in time when I reassembled the mill. All marks are dead nuts and chain tensioner is set correctly. Thanks again for your help guys. (Ticks me off that I had bad NEW spark plugs sending me off in left field for diagnosing all this.) But I'm on the right track. Just have to lean it out a bit. Might just be carbs, but I'm looking deeper as recent fine tuning didn't change things much. I also started useing 93 octane gas as Bills book mentions the sensitivity of these motors to different fuel grades. Which brings up another concern. I'm in Wisconsin, (Land of the crappy additive gasoline) that adds up to 10% ethanol. I'm sure that is part of my problem along with the fact that it is UNLEADED. I'm gonna get some lead additive and add that to see if it helps. Also looking at racing fuel that is up around 110 octane, but will mix with out crap gas and lead additive instead of running straight. (Don't want to melt my mill down or blow it up. Well guys that's about all of the updates this LWB has for now. I appreciate your help and will keep you posted further.

[65hawkchopper]

I'm sure that rescuers will arrive soon but you didn't mention whether you had checked plug leads / caps. One of the recommendations I hear a lot here is to trim back 1/4 inch of the plug lead are reinstall the cap to get a better connection.

You also may need to check the carbs again in case you have some dirt in the tank etc. Odd that it changes right / left as you say. Do you have a fresh, well-charged battery?

Good luck!

G

Sorry g-man; forgot to address your post. First off, thanks for your help. Battery is fully charged and charging system is up to snuff. I redid all the ignition wiring and included new secondary wires to plugs. Tested all ignition components after installing new points and setting things according to bill silvers book.

[LOUD MOUSE]

Ya don't need Lead Additive. .............lm

I'm sure that rescuers will arrive soon but you didn't mention whether you had checked plug leads / caps. One of the recommendations I hear a lot here is to trim back 1/4 inch of the plug lead are reinstall the cap to get a better connection.

You also may need to check the carbs again in case you have some dirt in the tank etc. Odd that it changes right / left as you say. Do you have a fresh, well-charged battery?

Good luck!

G

Sorry g-man; forgot to address your post. First off, thanks for your help. Battery is fully charged and charging system is up to snuff. I redid all the ignition wiring and included new secondary wires to plugs. Tested all ignition components after installing new points and setting things according to bill silvers book.