info on alpha one gen 1? water pump base..

[FORREST3]

Hey guys/gals..have a 1984 ( I completely restored as original to new, interior/engine etc..)chapperal xlc mercruiser 305 228 replaced water pump before, now due for another one (went bad)..confused about what I'm seeing now.. pre-84 does not have a pre-load pin on drive shaft ( mine does not)..what I'm seeing is I need a pre '84 pump..so I ordered one WITH the base this time and it has a 3/8 drilled/ tapped hole in the side of the base..my previous one does not..what is that hole for?? I searched alot and no answers I could find.. I sure would appreciate any info on this!?... Thanx... Forrest

 

[FORREST3]

Probably just going to plug it with a brass threaded plug..searched "google" for drilled/tapped hole in aplha water pump base..(

GLM 12110)​

to no avail..O/K??

 

[Scott06]

Hey guys/gals..have a 1984 ( I completely restored as original to new, interior/engine etc..)chapperal xlc mercruiser 305 228 replaced water pump before, now due for another one (went bad)..confused about what I'm seeing now.. pre-84 does not have a pre-load pin on drive shaft ( mine does not)..what I'm seeing is I need a pre '84 pump..so I ordered one WITH the base this time and it has a 3/8 drilled/ tapped hole in the side of the base..my previous one does not..what is that hole for?? I searched alot and no answers I could find.. I sure would appreciate any info on this!?... Thanx... Forrest

Whats your drive serial number

 

[Bondo]

Hey guys/gals..have a 1984 ( I completely restored as original to new, interior/engine etc..)chapperal xlc mercruiser 305 228 replaced water pump before, now due for another one (went bad)..confused about what I'm seeing now.. pre-84 does not have a pre-load pin on drive shaft ( mine does not)..what I'm seeing is I need a pre '84 pump..so I ordered one WITH the base this time and it has a 3/8 drilled/ tapped hole in the side of the base..my previous one does not..what is that hole for?? I searched alot and no answers I could find.. I sure would appreciate any info on this!?... Thanx... Forrest

Ayuh,..... On those older drives, the pump base comes with the flush hole,.... or not,.....
If yer drive doesn't have the hole, you need the other pump base,.....

 

[FORREST3]

Whats your drive serial number

Thanx guys..it's 6826462..and it DOES have the pre-load pin..made an error in my first post.I now have a SEI 106 upper..working great!..I'm using the original lower unit also...I have been using a base with no hole in it..works fine.. BUT since I have an "early alpha" with the pin.. not sure what to do..The one I ordered with a base according to their description, this is the correct part

GLM 12110 (Mercruiser MC-1 / R (1970-1983 and my serial #6826462 with pin) this is what I got..with the hole, ..can't I just plug it?..what does/did this hole hook up to?..sorry about the bold..just appeared..Thanx!... Forrest​

 

[76SeaRay]

I am unclear on your comments about the pre-load pin. From all of my research, the pre-load pin is for the 1974 to 1982 drive and the 1983 on does not use a pre-load pin. The 1983 on uses a different method for pre-load. If yours has the pin, then it would be pre-1983 or could be a mixture of pre-1983 and post 1983 parts. I don't know how this affects the pump and hole you are describing. Your serial number fits in the range for 1983 to 1990 so shouldn't have a pre-load pin. Maybe the lower unit was swapped from the original?

 

[FORREST3]

I am unclear on your comments about the pre-load pin. From all of my research, the pre-load pin is for the 1974 to 1982 drive and the 1983 on does not use a pre-load pin. The 1983 on uses a different method for pre-load. If yours has the pin, then it would be pre-1983 or could be a mixture of pre-1983 and post 1983 parts. I don't know how this affects the pump and hole you are describing.

This boat was manufactured in early '84..must explain the "mixing of parts" (I'm very familiar with that, own a shop) I have seen pump descriptions saying "thru 1983" AND thru 1984? with/without preload pin..At this point I guess it's irrelevant..BUT what does the hole do?..I can just plug/epoxy it I guess..? But according to "BONDO" I need to get a different pump base..why?.. what? a pump made for my lower unit that does not match manuf. descriptions?? Confusing to say the least..The complete pump kit is identical with my other pumps..only difference is this darn HOLE and just wondering the particular reasoning of it's existence..(flushing? How?) No info I could find on it..LOL?....Thanx abunch!... Forrest

 

[FORREST3]

Well I think I figured out the hole lay-out..Have another later L/U (after 86)..mine has a little "divet/indentation" on the outside of case located exactly inline with the hole in p. base.. (later L/U does not) I assume where they would drill case and put in access to the hole in the side of the water p. base..I get it I think?!..my L/U..is one of the last ones to have this "flush access".. but obviously it was NOT installed/completed when manufactured ( transitional piece?)..soo..I believe it should be o/k to plug the p.base hole since all other dimensions are identical..should be o/k? Thanx

 

[Bt Doctur]

A quick way is to look at the lower shaft with the pump base removed, If you see the bearing and race you need the MC1 pump base. If you see a ring with 4 slots you need the R/MR base

 

[FORREST3]

Thanx Bt..yes I know..I have that later l/u ( that I'm not using) has the ring with slots..my current l/u does not..it is a mc-1 apparently but without the flush access ..a one off I guess..there are bases without the "hole" that will fit mine but I guess others have the hole apparently..the later bases are also too large to fit down into the bearing race hole of a MC1 not to mention the "raised bump" the later l/u's have that prevents the early bases from setting down flat when mounted..well,, I think I understand all this?.LOL. Hopefully all this info might help others..if no=one has a reason why I should not just plug the hole I'll move on!... Thanx for all!!

 

[Bt Doctur]

MC-1,R with preload pin
46-57234A1, Sierra 18-3417

 

[FORREST3]

Thanx..I really appreciate the info BUT.. it amazes me that none of these vendors show the side with the hole in it..I ordered the GLM kit and it shows it has the 46-57234A1 as the base in it's kit..and it DOES HAVE the hole..this is b.s.,how do I know if I order just the ..46-57234A1 from anyone it will NOT have the hole ( no one shows that side?) from who?? GOD..this is nuts.. here's what I ordered...comes with this base... "oem base part# 46-57234A1" https://www.boatpartheadquarters.co...eawater-Pump-Kit-Drive-Mounte-p/glm-12110.htm

 

[Scott06]

Thanx..I really appreciate the info BUT.. it amazes me that none of these vendors show the side with the hole in it..I ordered the GLM kit and it shows it has the 46-57234A1 as the base in it's kit..and it DOES HAVE the hole..this is b.s.,how do I know if I order just the ..46-57234A1 it will NOT have the hole ( no one shows that side?) from who?? GOD..this is nuts.. here's what I ordered...comes with this base... "oem base part# 46-57234A1" https://www.boatpartheadquarters.co...eawater-Pump-Kit-Drive-Mounte-p/glm-12110.htm

Thats why you ask guys like BT who have been doing it for years. Thats what he forum is for.

 

[FORREST3]

soo.. I only found a sierra one here (searching for 30 minutes) and it actually says "without flush".. but guess what?? OUT OF STOCK... https://www.boatid.com/sierra/cooling-pump-base-mpn-18-3417.html

 

[FORREST3]

Thats why you ask guys like BT who have been doing it for years. Thats what he forum is for.

I understand that for sure!.. but still no help as of yet..please read entire previous post..frustrating to say the least

 

[Scott06]

soo.. I found a sierra one here (searching for 30 minutes) and it actually says "without flush".. but guess what?? OUT OF STOCK...

Yeah i love this forum but the iboats parts search leaves a lot to be desired.
in my experience the oem merc water pump kits are worth the extra few bucks.

I changed my gen 2 impeller this year after 6 years /300 hrs was in perfect condition. Did my neighbors a few years back ten years old original impeller and also in perfect shape.

 

[FORREST3]

I agree..But BT doctor, I really appreciate your help....""Houston we have a problem" frustrating thing is that the only base that I could find "without flush/hole" is out of stock.. all the others do not specify..soo apparently there are 2 types of Sierra 18-3417 bases for the MC-1/R.. one with flush and one without..just looked at the picture of the kit I bought and it DOES NOT have the hole in base, the one I got does! amazon geez! Now..the problem is, no others specify that info just for the base and looking at DOZENS of pictures/ads all over the place ( ebay,google etc..).. it's a gamble so far....Happy Thanksgiving all!!

 

[76SeaRay]

Does this resolve your question about the hole/no hole and part numbers?

Link below, scroll down the page for individual base part descriptions:

MerCruiser Water Pump Service Kits - MerCstuff.Com

 

[Bt Doctur]

 

[FORREST3]

Does this resolve your question about the hole/no hole and part numbers?

Link below, scroll down the page for individual base part descriptions:

MerCruiser Water Pump Service Kits - MerCstuff.Com

Yep I looked at that page a couple of days ago..says 3417 does NOT have the hole, 3421 does DUHH..I get that ..but most 3417's actually do, don't know why, fact is they do.. go look on ebay or other sites, I have for hours....I hope you understand this.. I was just going by what BT said earlier and that's the problem, 3417's (new in bag/box) DO have the holes also..problem is finding one that definitely doesn't, that's not out of stock (and that actually SAYS W/O flush) ....I don't want a hole..LOL!..I'm just plugging mine ( 2 part plastic epoxy), this is nuts/crazy gone on long enough, and I really do appreciate your efforts! I did the research and that's what I found.. thanx!. Thanx anyway..Forrest.. examples of MANY like this.. https://www.ebay.com/itm/124558154704?hash=item1d003e9bd0:g:0LAAAOSwK61gGv5J https://www.ebay.com/itm/294537462792?hash=item4493cd0408:g:akUAAOSw9CRhi~r6