timing belt broke need assistance with

[dirtroadmaffia]

1978 chrysler 85 hp timing belt broke and i have relaced it. flywheel has plate on it with timing marks and tdc. distributor gear pulley has mark on it. do i line up the tdc mark with the mark on pulley and install belt ?

 

[Frank Acampora]

Re: timing belt broke need assistance with

First, lets assume you have removed the flywheel and the new belt is in place under the flywheel and around the internal flywheel pulley. Next: Did you tighten the flywheel nut to 95 foot pounds torque? If too loose, it will spin and shear the key.

Loosen both bolts on the distributor mount (9/16 wrench). About 1 turn should do--you need to be able to wiggle the distributor a bit in addition to adjusting it in or out.

Set the 0 degree mark on the flywheel to the 0 degree mark on the pointer above the carbs. You are now at Top Dead Center.

Set the pulley on the distributor so that the curved line on top of it matches the curve of the flywheel and the straight line in the center of the curve is pointing directly at the flywheel. It may point directly at a tooth or in between teeth of the ring gear--not critical as long as the curve and straight lines match the flywheel.

Slip the belt over the distributor pulley. Now gently snug the left bolt just tight enough to take out any slop in the distributor mounting. Move the distributor out to snug the belt. When you do this, depending on how loose the belt was you may find that the pulley is off by one tooth on the belt. If so, re-adjust the belt and pulley. HOWEVER: It has been my experience that the belt and pulley is NEVER exactly on the line so don't worry if the mismatch is less than one tooth of the belt. What you are doing is setting the rotor to the #1 terminal and since the rotor moves about 1/2 inch in relation to the terminal as the distributor turns to advance timing, a slight error won't hurt anything.

NOW: THIS IS IMPORTANT! Snug the belt so that an .010 feeler gauge pointed like your index finger deflects the center of the belt 1/8 to 3/16 inch before bending. Then tighten both distributor mounting bolts.

If the belt is too loose, it will flap excessively and timing will not be uniform and constant. IF IT IS TOO TIGHT, the distributor will bind and the engine will not shift correctly. Linkage will bind up and you will fight to get it into and out of gear.

Pump a little fresh grease into the zerk fitting on the side of the distributor pivot.

There ya go! Total task should take 10-15 minutes working slowly and carefully.

 

[dirtroadmaffia]

Re: timing belt broke need assistance with

Thankyou so much. I set back exactly like you said and it fired up after some pettin. idles perfect. the motor hasnt run in 6 years and when i was checking things, starter the old belt broke. I redone the carbs so it wouldnt run lean and so far everything is working great on it. trim etc. everything. only paid 200.00 for the boat motor and trailer. once again thanxs a million.

 

[steelespike]

Re: timing belt broke need assistance with

First, lets assume you have removed the flywheel and the new belt is in place under the flywheel and around the internal flywheel pulley. Next: Did you tighten the flywheel nut to 95 foot pounds torque? If too loose, it will spin and shear the key.

Loosen both bolts on the distributor mount (9/16 wrench). About 1 turn should do--you need to be able to wiggle the distributor a bit in addition to adjusting it in or out.

Set the 0 degree mark on the flywheel to the 0 degree mark on the pointer above the carbs. You are now at Top Dead Center.

Set the pulley on the distributor so that the curved line on top of it matches the curve of the flywheel and the straight line in the center of the curve is pointing directly at the flywheel. It may point directly at a tooth or in between teeth of the ring gear--not critical as long as the curve and straight lines match the flywheel.

Slip the belt over the distributor pulley. Now gently snug the left bolt just tight enough to take out any slop in the distributor mounting. Move the distributor out to snug the belt. When you do this, depending on how loose the belt was you may find that the pulley is off by one tooth on the belt. If so, re-adjust the belt and pulley. HOWEVER: It has been my experience that the belt and pulley is NEVER exactly on the line so don't worry if the mismatch is less than one tooth of the belt. What you are doing is setting the rotor to the #1 terminal and since the rotor moves about 1/2 inch in relation to the terminal as the distributor turns to advance timing, a slight error won't hurt anything.

NOW: THIS IS IMPORTANT! Snug the belt so that an .010 feeler gauge pointed like your index finger deflects the center of the belt 1/8 to 3/16 inch before bending. Then tighten both distributor mounting bolts.

If the belt is too loose, it will flap excessively and timing will not be uniform and constant. IF IT IS TOO TIGHT, the distributor will bind and the engine will not shift correctly. Linkage will bind up and you will fight to get it into and out of gear.

Pump a little fresh grease into the zerk fitting on the side of the distributor pivot.

There ya go! Total task should take 10-15 minutes working slowly and carefully.

A darn nice explaination.

 

[Jack Daniels]

Re: timing belt broke need assistance with

someone should make this a sticky thread, with that explanation it will be used more than once.