merc risers and manifolds ??

[bones774]

In the middle of summer I bought a boat with the 260hp merc v-8 engine, it's running fine at this time, I just read Pascoe's article about boat maintenance and now have some ??
It's obvious he thinks merc is not the best quality, I don't know the past history of boat and would like some direction re: maintenance/inspection of risers and manifolds.
There are no apparent leaks or stains on the block right now and those parts look clean and unstained and nice original looking paint.
One note, at extended low speed idle or slow cruise the temp starts to rise into the higher side of temp gauge, but underway the temp is fine.
Thanks

 

[Chris1956]

Re: merc risers and manifolds ??

The motor overheating at idle is indicative of a worn out water pump impeller. I recommend you replace it.

It is hard to inspect the manifolds and risers for their condition. What year is the motor? Are the manifolds original (Merc brand)? Manifolds last a bit longer than the risers, however, not too much longer. In salt water, you can safely get 8 years out of a set. Fresh water life is much longer, say 15 years.

You can pull the rubber sleeves on the rear of the risers and look at the condition of the seperator between the water jacket and exhaust passage. If it has rust holes, you are near the end of it's life. If one riser/manifold is hotter than the other while the motor is running, it is more clogged, and closer to the end than the other.

 

[bones774]

Re: merc risers and manifolds ??

Water pump impeller? Is that the one inboard at front of engine(water pump) or on the outdrive? Is this servicable by a competent DIY'er?
The motor is an 1988, don't know if original, they are mercs, always fresh water use.
I'll pull those rubber manifolds just before spring and take a look.
Thnaks

 

[ziggy]

Re: merc risers and manifolds ??

i think the alpha1 impellers are fragile. don't even think of running it w/o waterflow to the drive. it'll be toast in short order... http://www.boatfix.com/merc/Bullet/87/87_14.pdf
my 1 drive uses the same one.
i replace it every year and every year for three years now it always shows some sign of degrading...

best i understand, the impeller in the drive is always the first suspicion for any overheat condition.... specially if ya ain't serviced it for a while. yes, it's a diy type item... not the easiest project the first time but certainly doable, and the more ya do it, the easier it'll get..

 

[bones774]

Re: merc risers and manifolds ??

I'm gonna order the impeller soon, but can someone explain to me the differences in Alpha's and Bravos and different generations?
For future knowledge,
Just to remind I have a 1988 merc 260hp, 350 v-8, if that helps.
Thanks

 

[Ohioriver]

Re: merc risers and manifolds ??

Well yours should be an Alpha 1 Gen 1, Alpha 1 gen 2 came out in 1991 I think, Bravo 1 came out in 1988 but it was for the 454 big block engine at the time, now its for anything over 300 hp. There a chart in one of the posts on here some where that shows all the drives and their years.

 

[bones774]

Re: merc risers and manifolds ??

just took a look on web auction site ans saw dealer offering "better" aftermarket impeller kit that has a brass insert anyone familiar? would like to find the chart beforehand to be sure. thanks

 

[Bondo]

Re: merc risers and manifolds ??

would like to find the chart beforehand to be sure.

Ayuh,... What Chart,..??

 

[skargo]

Re: merc risers and manifolds ??

http://www.mercstuff.com/drive_id.htm

 

[bones774]

Re: merc risers and manifolds ??

Thanks Skargo, nice and clear, no mistakes with that info.

 

[skargo]

Re: merc risers and manifolds ??

Thanks Skargo, nice and clear, no mistakes with that info.

No problem, it helps, especially with older boats where the drive may have been swapped out for a newer version. Case in point, my boat is a 78, yet has an Alpha one, swapped on by the PO.

 

[Bondo]

Re: merc risers and manifolds ??

especially with older boats where the drive may have been swapped out for a newer version. Case in point, my boat is a 78, yet has an Alpha one, swapped on by the PO.

Just to remind I have a 1988 merc 260hp, 350 v-8, if that helps.

Ayuh,... Considering the Merc impeller pumps were All the same up to 91,...
It's abit of a moot point ain't it,..??
Even if somebody had mounted a Model 1 on the OP's Alpha 1 transom housing...

 

[skargo]

Re: merc risers and manifolds ??

Ayuh,... Considering the Merc impeller pumps were All the same up to 91,...
It's abit of a moot point ain't it,..??
Even if somebody had mounted a Model 1 on the OP's Alpha 1 transom housing...

Not a moot point at all, as I explained it. Nowhere did I say in HIS case would that be true.

All I did was post a GREAT link on identifying drives, I wasn't trolling for your usual crass comments

 

[bones774]

Re: merc risers and manifolds ??

well as a newbie I don't know all merc impellers were the same, and looking online is a bit confusing, I also thought about parts swapping as my boat is a bit older as a 1988.
Skargo I agree with you, I also thought the remarks to be crass, would expect more from a senior member of this forum.
I'll bet that was the first time alotta people saw that outdrive ID page.
Thanks all for your HELP.

 

[ziggy]

Re: merc risers and manifolds ??

It's abit of a moot point ain't it,..??

i'd think so too.
especially when the oem impeller kit says right on it...

"fits mercury/mariner 65hp (4cyl.) through v-6 models with short-vaned impellers and mercury mercruiser 1/r/mr/alpha drives (s/n2495186-OD469858)


as for mercstuff. while i like there site and have used it i take what they say and what they sell with a grain of salt. what they sell is what concerns me most (glm aftermarket parts which i think are substandard parts). ie the tap they sell for tapping a model 1 dive shift cable from oem on the ft. of the bellhousing to the back for the new style. the tap they sell is tapered... which is wrong..

for drive application i use the mercrusier engine/drive model year referance chart that was posted up by just jason i think.. i believe that chart. unfortunately i could not find a link to it and only have it in pdf that i can't seem to get to paste into the forum..

well as a newbie I don't know all merc impellers were the same, and looking online is a bit confusing, I also thought about parts swapping as my boat is a bit older as a 1988.

if your gonna look online. use a website that sells oem parts and id your drive by s'n so you know what you have. don't forget about your mercruiser dealer either. they will provide the correct parts too. and if they have questions about what you have, they will id it by s/n so they know what you have. get to be friends with your local dealer too. they can be a great resource too....

as for the better impeller, i don't believe it. what i do believe is ya need to check your impeller no less than once a year for alpha1 and older. and if yer gonna have to go look at it. ya might as well replace it since the impeller is always the first place to look for overheat conditions.. + it is often a a neglected maint. item since it's not the easiest item to go look at...

 

[Bondo]

Re: merc risers and manifolds ??

Quote:
Originally Posted by Bond-o
Ayuh,... Considering the Merc impeller pumps were All the same up to 91,...
It's abit of a moot point ain't it,..??
Even if somebody had mounted a Model 1 on the OP's Alpha 1 transom housing...
___________________________________________________________________________

Not a moot point at all, as I explained it. Nowhere did I say in HIS case would that be true.

All I did was post a GREAT link on identifying drives, I wasn't trolling for your usual crass comments

Ayuh,... Well,... I'm glad you like my wit,& wisdom,...

As for your link,... It's actually an Illegal link if you'd read the posting guidelines here at iboats...
It's against forum rules to post links to Competing websites...
Because Merstuff Sells parts in direct competition with iboats...

well as a newbie I don't know all merc impellers were the same, and looking online is a bit confusing, I also thought about parts swapping as my boat is a bit older as a 1988.
Skargo I agree with you, I also thought the remarks to be crass, would expect more from a senior member of this forum.
I'll bet that was the first time alotta people saw that outdrive ID page.
Thanks all for your HELP.

Ayuh,... I do my best to post Factual Answers,...All with a Single Digit....
If that happens to sound Crass,... So be it,...
I'll be sure to leave Both of you alone from now on,....
Unless of course I see False Info being spread about.... Muchless the Illegal postings....

 

[skargo]

Re: merc risers and manifolds ??

Illegal?!?!?!?!?!?!?!?!?!?! OOOOOKKKKKK buddy. I at least helped the poster, you, on the other hand, make yet another sarcastic remark. Heck, you've done it to me before, and I typically just ignore you, which I would have been better served by doing in this case.

As to the link I posted, MANY times it's been posted here, and for identification purposes, it is perfect. I never said to go buy anything there, nor did I ever say their products were good, bad, or otherwise. I couldn't as I have never donw business with them. I do appreciate their identification guide though.

Wit and wisdom, hooooboy, thanks for the chuckle!
hehehehe, Illegal he says, I guess the thousands of links posted here will cause the "perps" to be incarcerated hehehehehe


BTW, these are JUST the identical link I posted, illegal HAHAHAHA
http://www.google.com/search?hl=en&...hts=&as_occt=any&cr=&as_nlo=&as_nhi=&safe=off

 

[bones774]

Re: merc risers and manifolds ??

Sorry for all the trouble guys.
Anyway, there was a line about your local merc dealer being of assistance, not quite sure that's gonna happen.
I walked into my local dealer with woodruff key in hand and told them what engine it came off of but no serial number, the woman went to great lengths looking thru catalogs and telling me she needs serial number for motor, I politely tried to tell her that there are probably not that many keys and if she just showed it to mechanic in back he would pick it out of stock in a moment. That didn't happen and I walked out w/o the part.
Was I wrong in my assumption?
I believe it's a husband and wife operation recently bought by them solely as a business venture, with very little experience.

 

[Bondo]

Re: merc risers and manifolds ??

Illegal?!?!?!?!?!?!?!?!?!?!

I stand corrected,... The posting guidelines changed awhile back...

I guess out of respect to the folks paying the rent here,...
I try to post links to the resourses here at iboats...
The Information requested by the OP can be found right Here....

Bones,.... Everything revolves around the Serial #....
The motor's serial # should be on a little aluminum tag riveted to the block, just ahead of the starter...
Otherwise,... Spending some time on an OEM parts look-up site, as noted by Ziggy can yeild a serial # range that'll get you what you Need...

 

[ziggy]

Re: merc risers and manifolds ??

Everything revolves around the Serial #....

that's the way i understand mercruiser id's too.

The motor's serial # should be on a little aluminum tag riveted to the block, just ahead of the starter...

+ there may be a serial number on the transom assy. and there should be a s/n on the port side mercrusier decal and posibly a gear ratio stamp too... i'm not sure about alpha1's but the older model 1's also had the s/n stamped into the upper itself. under the mercruiser sticker... the proper service manual for your set up will likely have pics to help you locate them also.. #6 for alpha1's...

I walked into my local dealer with woodruff key in hand and told them what engine it came off of but no serial number, the woman went to great lengths looking thru catalogs and telling me she needs serial number for motor, I politely tried to tell her that there are probably not that many keys and if she just showed it to mechanic in back he would pick it out of stock in a moment. That didn't happen and I walked out w/o the part.
Was I wrong in my assumption?

i don't know. if i was selling the part, i think i'd want to know that i'm selling the customer the right part. not much is more frustrating to a customer than to have the part in hand and be ready to do the deed only to find it's the wrong part... just my 2 cent on that.. give them a chance and find your s/n, there not hard to locate... again, the proper s/m will likely have pics to help locate them if you can't find it..

side note. i had a 165hp L6 that was a replacement engine. so it didn't have a s/n on the engine. it'd been replaced and was not a mercruiser block, probably out of a truck. then further investigation is in order to fig. out what you have so you can get parts by being within the suspected s/n range at that point..