5,7 350 question

[stevo18]

I have an old 88 Peterborough Indy with stock motor 350 260hp Rochester vaccum carb and would like to swap carb for a mecanical Holley
so question is what type of Holley and jet set up do I need to run to make the conversion
if theirs another site or forum page that could give me more info let know I know s&f is more outboard related than inboard
thanks in advance
steve

[idvette]

Why make the change? First of all, the Holley will be a squarebore carb, you'd need an adapter to get it to fit on your spreadbore intake. A carb with vacuum secondaries basically works off the air demand of your engine, so part throttle cruising and acceleration are smoother. And when built right, a q-jet will perform just as well as anything out there. Personally I wouldn't bother replacing it, have someone who knows q-jets to do a performance rebuild on it.

[Dave Strong]

Leave the Q-Jet on it.

Dave

[tlwjkw]

one thing leads to another then another then another and so it goes..... least with most on this board... go ahead with a 383 and goodies then be done with it!............or like suggested, fix what ya got......jmo

[stevo18]

ok I look into that soon I may have someone around my place that can help me to rebuild and tune my old carb. hope kits are still availlable.
if not will check to replace it
theirs a lot of things that have been done to this boat in its life time some good some bad some realy bad... but I want to bring it back to good running condition not looking for power I want reliability.
thanks for the info
more is welcomed

[tlwjkw]

check Summit.... kits and replacement Q-jets.......

[delawarerick]

Key is have someone that knows q-jets I had one redone and it does just fine on the donzi.

[stevo18]

ok thanks I will check all my options

[stevo18]

I already named it miami-splice since each and every wire in the boat has been spliced. I'm suprised when I tryed it last year that everything works !!!
will have to put in lots of hours to fix this mess but overall the boat is in fare to good condition for its age.


http://i1258.photobucket.com/albums/ii524/polaris1220/image_zps24nvjf2c.jpg (http://s1258.photobucket.com/user/polaris1220/media/image_zps24nvjf2c.jpg.html)

[racervboat]

Holley makes a q-jet spread bore replacement carb but I would keep the q-jet,when they work good they are just as good or better than a holley. jmo

[Robby321]

For what its worth my last IO 350 had a "Q" on it and didn't like it. Tossed a Edelbrock on, (comes with the adapter plate) and never looked back..

[FMP]

This is the second time I'm trying to post this, about and hour ago typed it all out and then all gone....
Qjets are fine for the hp and displacement you are running. You could find a larger cfm big block Qjet but it woundn't help you with the small heads . Get Alc. resistant rebuild kit , good accel. pump, seals, from a performance Qjet supplier. Get the float right . Once you have the rebuilt on tune the primary and secondary mix. I wouldn't go to any lenghts trying to rework the circuits, you aren't in that HP range. But I would try get the right fuel A/F mix idle circuit to wide open. The primary metering is easy to tune and the stock metering rods should be fine. The secondary rods can be changed to get the mix right. The mix should be near lean, you want a blue flame check the burn.The secondary opening can be adjusted sooner , its probably a bit late and fat. The rebuild and tune work can be done by you , just read up on it. The metering rod chart can also be found on line. The Qjet shop should be able to get you everything. If you buy a new carb it will only be close to tune for you setup unless you get a rebuilder that knows exactly how to tune the carb for you, not just one off the shelf.

[Dave Strong]

Sierra sells the right kit for the 260. The carb should be jetted and have all the correct metering rods, hanger and power valve springs. Just rebuild it, have many customers with 260's and never seem to have any carb issues.

Dave

[vnemous]

Very easy to rebuild and for what your doing its just fine. Wouldn't waste the money on anything other than a rebuild kit. I believe the kit number is 823426a1 and msrp is $31.67 from Mercury JMO

[FMP]

http://www.cliffshighperformance.com/parts.html
http://quadrajetparts.com/rochester-quadrajet-c-128.html?osCsid=3587fb044c5e56a7dd3dbffc3d802303
http://www.carburetor-parts.com/Mercury-Marine_ep_384.html
A quick look shows the carb foe the 260 was on a lots of other size and hp engines , so it might be range tuned only.

[stevo18]

thanks for the great info guys will look up and read on my q-jet carb and rebuid it and tune it

I know I have to check the timming to on it since past owner changed out the cap, plugs and wires but based on his skills it's the first thing I will check before messing around with the carb.
I will have to get info has what is factory timming set up for this motor or probably one of you guys know what it is
lots of knowlogable guys on this site it's great
thanks for anymore info