# Timing Honda GXV620



## Beenthere

This is my first contribution to the forum. While I have been involved with small engines since childhood, mechanics were not a part of my career. Since retirement, however, I have pursued my interest in small engines and spend a lot of time repairing lawn mowers. My customers are primarily the elderly, widows, and others who cannot afford expensive local repair shops. I pride myself in being a "repairman" who goes the extra mile reapairing the broken parts rather purchasing new parts unless absoutly necessary. 

At the present time I am in process of rebuilding a Honda GXV620 20hp. I have encountered a problem I am not familiar with. The crank shaft is equipped with a pressed-on cam gear. I cannot find a timing mark on the gear. The cam shaft gear however is clearly marked. Can someone advise the process of timing the two gears? I have not located an overhaul manual in this rural area. Any help will be appreciated. 

Beenthere


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## 30yearTech

Have a look at this.


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## Beenthere

*30yearTech*



30yearTech said:


> Have a look at this.


I appreciate your quick response. I could print only half of the schematic photo you sent. My problem is.. There is no punch mark on the timing gear. I have overhauled many small engines but I have never worked on one that did not have a well defined mark on the crankshafe timing gear as well as the cam shaft gear. My concern is, if I purchase an overhaul manual, it may well advise exactly what your information has suggested and I will not be any better off plus I will be out the expense of the manual. I live 50 miles south of Jackson, MS. I know I can find a Honda parts supplier there. Maybe I can take my crankshaft there and compare it to a matching part and determine where the punch mark should be. If the engine was a single cylinder I believe I could determine the correct setting without the mark. I am not sure since it is a twin. thanks again. Beenthere


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## 30yearTech

I only posted the part with the timing gear alignment picture, so the whole page is not available to print. There is no punch mark on the timing gear. Use the "rib" on the timing gear and align with the mark on the cam gear.


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## Beenthere

30yearTech said:


> I only posted the part with the timing gear alignment picture, so the whole page is not available to print. There is no punch mark on the timing gear. Use the "rib" on the timing gear and align with the mark on the cam gear.


I am calling the gear on the crankshaft, the timing gear and the gear on the camshaft the cam gear. There is a "rib" on the cam gear but there is no mark of any kind on the crankshaft gear. Since this is the first GXV620 I have torn down, I was wondering if there may be a different technique used for timing the two gears that is unique to this particular engine? Anyway, I appreciate your efforts to help me out. If you can think of anything else I can try please let me know. 

Beenthere


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## 30yearTech

Beenthere said:


> I am calling the gear on the crankshaft, the timing gear and the gear on the camshaft the cam gear. There is a "rib" on the cam gear but there is no mark of any kind on the crankshaft gear. Since this is the first GXV620 I have torn down, I was wondering if there may be a different technique used for timing the two gears that is unique to this particular engine? Anyway, I appreciate your efforts to help me out. If you can think of anything else I can try please let me know.
> 
> Beenthere


That's exactly how I am describing the marks. I tried to find a picture to no avail, but the mark is not on the side of the timing gear, look at the top of the teeth and one of the teeth should look a little different then the rest. That's the one you align with the mark on the cam.

If you can't identify the tooth on the gear, then rotate the flywheel until the "T" mark on the cooling fan aligns with the "T" mark on the right side of the fan cover. (This alignment point is the top dead center of the No. 1 cylinder.) Install the camshaft so that both valves on #1 are closed. This should get you pretty close if not exactly where you need to be. Rotate the engine and observe the valve train operation for both cylinders. Note: the "T" marks on both sides of the fan cover are where you need to be to set the valve lash, just be sure when you set the clearances, that you are on the compression or power stroke for the cylinder you are setting the valves on.


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## Beenthere

30yearTech said:


> That's exactly how I am describing the marks. I tried to find a picture to no avail, but the mark is not on the side of the timing gear, look at the top of the teeth and one of the teeth should look a little different then the rest. That's the one you align with the mark on the cam.
> 
> If you can't identify the tooth on the gear, then rotate the flywheel until the "T" mark on the cooling fan aligns with the "T" mark on the right side of the fan cover. (This alignment point is the top dead center of the No. 1 cylinder.) Install the camshaft so that both valves on #1 are closed. This should get you pretty close if not exactly where you need to be. Rotate the engine and observe the valve train operation for both cylinders. Note: the "T" marks on both sides of the fan cover are where you need to be to set the valve lash, just be sure when you set the clearances, that you are on the compression or power stroke for the cylinder you are setting the valves on.


30Year Tech
My friend you have been a big help. I re-examined the crankshaft gear and I simply cannot find a mark or scratch of any kind. However, I believe you have provided sufficient other info that I will be able to properly align the gears without the mark. You have convinced me that you qualify to be called a mechanic. I mean that as a compliment. Somewhere on your communications I remember seeing that you are located somewhere in central Texas. I lived in Dallas for 20 years back during the 70's and 80's. 
When I have this engine finished I will let you know how it turned out.

Sometimes I would like to get your views on Ethanol and it's effect on small engines.

Beenthere


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## Shannon Abbott

Im having the same problem no timing mark on crank


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