No speedo hole in 1997 4.3lx Alpha 1 Gen+ lower unit??

[jcoelho]

I discovered why my speedometer doesn't work. There's no pilot hole on the leading edge of the lower unit. The upper unit has "4.3 Alpha 1 Gen+" written on it; there's a speedometer tube is attached to a petit...but NO hole on the leading edge of the lower unit. What's up with this? No, I didn't miss the hole on the leading edge. It is not there! Is this a replaced lower unit? If so what else would fit the 4.3 Alpha one Gen+?

 

[jcoelho]

Re: No pilot hole in 4.3 Alpha 1 Gen+

Re: No pilot hole in 4.3 Alpha 1 Gen+

It's a 1997 4.3lx alpha 1 Gen+....

 

[cr2k]

Re: No pilot hole in 4.3 Alpha 1 Gen+

Re: No pilot hole in 4.3 Alpha 1 Gen+

What is a gen+? Gen I or gen II? Maybe someone put a gen one lower on it.
Is there anywhere for the speedo tube to hook up on top of the lower right behind the nut? If not then there will be NO pickup in the drive.

 

[jcoelho]

Re: No speedo hole in 4.3 Alpha 1 Gen+ lower unit??

Re: No speedo hole in 4.3 Alpha 1 Gen+ lower unit??

It's a 1997 boat. I assume it's a gen 2. I see the petit or adaptor pick up where the upper and lower units attach. I can see where the hose attaches; have taken it off, blown thru it, etc. before I realized there's an issue with the lower unit. The lower unit does NOT have a hole on the leading edge, so the speedo hose goes to the drive fine but then is useless without a pick up in the lower. My question is: what lower unit might I have that would fit a Gen 2 and not have a speedo hole on the leading edge? I have another boat with a Gen 1, and I can see the differences. Are there other lower units that would fit GEN 2?

My next question: Is there a way to extend the speedo hose and use a transom mounted pickup? will I have to retrace the speedo hose and drill through the hull or can I just find an adaptor to add an extension to the hose and just have the hose exit the drive , then go to the transom?

 

[Bondo]

Re: No speedo hole in 4.3 Alpha 1 Gen+ lower unit??

Re: No speedo hole in 4.3 Alpha 1 Gen+ lower unit??

Are there other lower units that would fit GEN 2?

Nope...

My next question: Is there a way to extend the speedo hose and use a transom mounted pickup?

As inaccurate as pitot tube speedos are,.... I wouldn't even bother with it....
Get a GPS...

 

[Don S]

Re: No speedo hole in 4.3 Alpha 1 Gen+ lower unit??

Re: No speedo hole in 4.3 Alpha 1 Gen+ lower unit??

I've never seen a Gen II drive that didn't have the hole, but I have seen the hole so plugged up that it blended in perfectly. The picture below will give you a good idea where on the leading edge to look. It's there, I would bet money on that. I've actually had to drill wood out of a couple of them.

 

[havasuboatman]

Re: No speedo hole in 1997 4.3lx Alpha 1 Gen+ lower unit??

Don't be suprised if you find out the lower unit has been damaged and repaired. Or, as don mentioned, severely plugged, and then painted.
I wouldn't bother with it. Just whet your finger and hold it up to gauge your speed. It's nearly as accurate.

 

[zbnutcase]

Re: No speedo hole in 1997 4.3lx Alpha 1 Gen+ lower unit??

I have drilled wood several times and even bondo out once. Its there. 'nutcase

 

[jcoelho]

Re: No speedo hole in 1997 4.3lx Alpha 1 Gen+ lower unit??

It IS there. I would have bet my life it didn't exist...scraped away what I thought was paint, found a slight indent, carefully drill out wood? with a small drill bit by hand. I'm able to blow air through the hose when it is off the drive and speedo, but when blowing from the speedo end, with hose attached to outdrive, I can't force air in. Is this OK, or should the air blow clear through when hose attached to outdrive? Thanks.

New boat to me: 1997 Chaparral 1935 with 4.3LX. I'll start another thread for help with my other issues! There's more. I'm a relative newbie trying not to get frustrated. My third but most expensive boat investment seems to be giving me the most problems...should have stayed with my trusty 1989 OMC 2.3 or '89 mercruiser 4.3.

 

[Don S]

Re: No speedo hole in 1997 4.3lx Alpha 1 Gen+ lower unit??

It should be open from the drive to the speedo.

should have stayed with my trusty 1989 OMC 2.3 or '89 mercruiser 4.3.

Not really. What you have to do is get past all the problems the previous owner handed you. Never look back and say the OMC 2.3 was better. You were lucky then, but that's just crazy now.

 

[jcoelho]

Re: No speedo hole in 1997 4.3lx Alpha 1 Gen+ lower unit??

Thanks Don. I definitely need the encouragement with this boat. It really is a nice boat but I didn't expect some of the discoveries. I know the speedo is a minor issue but if I can solve this, it'll make me feel like I'm moving in the right direction.

Now that I have discovered the speedo hole in the leading edge of the drive, and drilled out some debris, should I force a small wire in - does the hole bend upward? I tried sticking a small wire down through where the hose attaches to the outdrive but it seems solid in there. The hose itself is clear and allows air through. Maybe I just can't blow hard enough. Would compressed air work better than my lungs!

 

[Bondo]

Re: No speedo hole in 1997 4.3lx Alpha 1 Gen+ lower unit??

Would compressed air work better than my lungs!

Yes...

 

[jcoelho]

Re: No speedo hole in 1997 4.3lx Alpha 1 Gen+ lower unit??

How far in should I hand drill/remove debris from the leading edge hole. I only went a 1/4 inch or so - didn't want to damage anything. Is there a hole in the adaptor to hose on the drive. Mine may be clogged there.

 

[Peter1950]

Re: No speedo hole in 1997 4.3lx Alpha 1 Gen+ lower unit??

If all else fails, get a transom mount pitot tube and attach your hose to that. That's how my boat came from new and it works fine. I broke it while polishing the transom a few months ago but it was only $6 new. I compared my speedometer to my GPS and to my amazement its right on.