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Tune up question

J

Jim Dunn

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" Had touble getting the point

" Had touble getting the points adjusted to get my Gray 135 hp flathead 6 to want to start. It starts fine now but wants to quit unless I warm it up at 2000 rpms. After warmup it idles down to 600 and runs just fine. Also, motor runs fine at speed but I have never been able to adjust the timing to stop the preingnition ping at 2700 rpms. Any ideas short of electronic ignition? "
 
" Jim,
The starting situat

" Jim,
The starting situation sounds like a carberator choke problem. Also any poor ignition component can add to the problem. Carbon build up in the cylinders can cause pinging. You may be able to get rid of the pinging by adjusting the timing.
Eddie "
 
" Eddie,I have adjusted the ti

" Eddie,I have adjusted the timing numerous times,when I advance it to stop the ping I have trouble starting. The plugs are the proper color and only have 50-60 hrs on them. I was going to change them this weekend anyway. I have just added a new choke cable to the twin carb Gray and both close as intended. The pinging limits my rpm's which is not all that bad on the newly rebuilt motor but the motor not wanting to remain running at initial start up is a problem that I would rather not deal with. "
 
" Jim,
If your choke is op

" Jim,
If your choke is opeating then the only fuel problem remaining is dirt in the idle curcuit. What condition is your carburator in? Also, how long has it been since the advance mechanism in your distributor has been serviced? Myself, I don't like getting into carburators and leave that as a last resort.
Eddie "
 
" Eddie,carbs were rebuilt las

" Eddie,carbs were rebuilt last year. How do you go about servicing the advance mechanism? That might solve my timing problem but might fix the cold motor shut down problem? Thanks for your help. "
 
" Jim,
I notice a couple mess

" Jim,
I notice a couple messages back that you mention you have adjusted the timing a number of times and that when you advance it to stop the ping, it becomes hard to start. Ping, or PreIGNition is a result of having the timing advaced too far to begin with. If it is already timed too high then advancing it will only worsen the problem by resulting in the cylendar firing well before it reaches top dead center so the starter is literally fighting against the power of the engine itself. That is why it becomes hard to start. In the old model-T fords there was many an arm broken by an engine kicking back if the timing was too high (hand crank models). Try retarding the timing bit by bit until you can go to WOT withougt experiencing the ping and it should solve the problem. Better yet if you can determine the proper setting and have the correct hormonic balancer and scale then set it to factory specs and call it happy. If it is pinging at factory specs then I would suggest following Eddie's advice on reducing carbon. Additionally extended running at WOT can serve to blow some of that carbon out as it breaks up. But I would not totaly discount the possibility of a one tooth jump on a timing chain which normally occurs at engine kill or start up if its going to happen so if this showed up suddenly then I could be a tell tail sign. At any rate, a timing adjustment in an effort to reduce or eliminate ping should be to back it off a bit, not to advance.

Just a few thoughts and as I have said before I am not an inboard guru but have done automotive work for years. I play with a few outboards. Just trying to offer what I believe to be good advice and some in here, with more experience, may have a different opinion so take what I say with a grain of salt. Get a second opinion if you feel the need or just disregard if you disagree.

Good luck with it and I hope you get it soon. The weather will be pretty soon and time at the dock kind of sux when you are watching every body else just drop-em-in and move-em-out. I know. I been there. "
 
" Jim,
Checking and clean

" Jim,
Checking and cleaning the distributor involves removing the distributor. You may want to do this now if you going to follow Johnyboy's advise and change the timing. Lift the distributor cap. Mark the position of the rotor for reinstallation. Note that if it is gear driven the rotor will rotate slightly as you remove it. You might want to mark that position also as start point for reinstallation. This part is not rocket science as the rotation of the rotor will be noticeably different if you are even one gear tooth off reinstalling. The centrifugal advance mechanism is composed of two weights that fly outward as the engine speeds up causing a plate to move causing the timing to advance. Springs pull the weights back in as the engine slows down. You will be looking for obvious damage such as a broken spring. Look for any restriction in the moving parts caused by dirt, corrosion or binding. Clean the area with part cleaner or laquer thinner. Put a little Inox or WD-40 on piviot points. There may be a wick in the center of the shaft under the rotor. This is for lubriction. Put a few drops of oil here now and every time you do a tune up. You can check your point gap easily while the distributor is out. Reinstall distributor, lining up the rotor to your marked positions. Adjust the timing following Johnyboy's advise.
Eddie "
 
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