Japanese prop markings (Suzuki)

Joined
May 16, 2007
Messages
6
I bought a spare prop for my 1983 Suzuki 5 HP two stroke twin. On the old prop it is marked.

F610
200x170

I ordered a prop from Browns Point Marine because they showed props in stock under the F610 part number for 1983 5 HP Suzuki's. When the new prop came in it is marked;

F710
200x190

I have poured over the parts book for this engine and the web site for Browns and can not seem to find the inch specs for the original 200x170 prop but I know something must be different. Anybody know what the markings mean?
 
Joined
May 16, 2007
Messages
6
Re: Japanese prop markings (Suzuki)

I did some digging and I "think" that the 170 prop is a 6.6" pitch and the 190 prop is a 7.4" pitch prop.

I also check the box the prop came in and it is marked F710 so they sent the wrong prop.

Before I send it back what is that gonna do to performance? If you can use that term for a 5 HP engine.

As I understand it it will run faster top end and have slower out of the hole and pulling power.

How much difference will 6.5 to 7.5 make?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Japanese prop markings (Suzuki)

You are correct in your assumption that more pitch translates to higher top speed but less hole shot. That assumption however is "theoretical". If the original prop was correct for the boat/motor combination -- meaning the engine did not over rev at wide open throttle and was within the maximum recommended rpm range, the engine may actually lose speed with the new prop because the engine does not have enough power to turn it at those RPM. In laymens terms, you may be lugging the engine which is not a good thing. On the other hand, the new prop may help. Since you have no tach or speedometer its hard to tell what the effect will be. I would be tempted to keep it, especially if you normally carry a light load. If your boat is heavily loaded (for its size), the new prop is probably a bad choice.
 
Joined
May 16, 2007
Messages
6
Re: Japanese prop markings (Suzuki)

I bought it for as a spare prop so I am going to contact the company. If it was a mistake and they are willing to exchange it for the correct prop I will do that.
I am satisfied with the original prop's performance.
However, if it is a substitution because they did not have the prop I ordered I may just keep it as a spare to carry on trips. You can't find these old Suzuki props in every boat store.
If I keep it I will test both props and post the results. I have portable GPS so I can check ground/water speeds. As far as RPMS.....I guess wide open throttle is all I've got right now.

Thanks
 
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