inline 6 fuel volume to low seeking help from clams

[webster101]

ok clams or anyone else who might know,after doing all timing and sych checks.rebulding fuel pump and carbs finally came down to fuel pump volume, looks to me when I take off the hose going to carbs and crank motor with kill switch pulled takes forever to fill one cup of gas?was told by somebody else loss of press working pump from motor but no details they were snowmobile techs but knew all about 2cycle motors claimed they worked the same and something about leaking crank seal or something.took off fuel pump cranked over motor checked pulse from motor it was there but when covering holes with fingers could hardly feel a thing.butted up vacuum hose to hole with fuel press gauge at other end bearly 4psi no spec's on this or other info in factory merc manual.have noticed many other same concerns in past threads could this be a common prob?is this to low of press going to pump?is volume to low?any input or help on methods of diag and/or repair would be of help.motor takes off fine when primer bulb is pumped on accel and have checked everything all lined and antiback flow valves checked for leaks in all lines and tank vents all good this is last possibility.I think im on to something.how about hooking up an electric fuel pump?I have been around for awhile been a car tech for 30 years things have to make sence to me

 

[Laddies]

Re: inline 6 fuel volume to low seeking help from clams

I don't know which inline you have but the ones with the pumps mounted on the cowlings and two pulse hoses running them are famous for the pulse hoses collapsing and not delivering fuel the fix is to install a coil spring inside each line to prevent the problem--Bob

 

[Clams Canino]

Re: inline 6 fuel volume to low seeking help from clams

Ya... those hoses are 1st suspect... the pulses don't feel real strong though anyway.<br /><br />-W

 

[webster101]

Re: inline 6 fuel volume to low seeking help from clams

fuel pump bolts on motor no hoses just gaskets. motor is a 1985 115 inline 6cyl with old style fuel pump.how about the crank seal theory?

 

[webster101]

Re: inline 6 fuel volume to low seeking help from clams

clams do you have a phone# I could call you if not I understand.

 

[Clams Canino]

Re: inline 6 fuel volume to low seeking help from clams

Ya... the email leads to a phone number... <br /><br />-W

 

[webster101]

Re: inline 6 fuel volume to low seeking help from clams

what is the deal?is this some sort of secret?about the crank seal leaking crankcase press so fuel pump wont work or what?from what Im told this is an common problem with 2-stroke motors or.....do we sell to many powerheads becuse of this I would not think so it's not like alot of people would be able to do this repair themselves or would they? hm.....nobody seems to whant to answer this question and is side steping the issue.

 

[Clams Canino]

Re: inline 6 fuel volume to low seeking help from clams

You fuel pump is driven by #3 and #4 in a push pull, the crank end seals would have little impact. So long as 3 and 4 measure up OK compression wise, they outta be enough to drive the pump. The labareth seal between #3 and #4 would have bearing on the issue, but not so much at any significant RPM, If it can run, it can pump too. If you pull the pump and spin the starter with no plugs, you outta be able to "feel the breeze" from those 2 holes that drive the pump.<br /><br />I'd put a pump kit in it, clean the carbs and set the floats and try it. The pump is rather low volume to begin with, but has plenty enough capacity to keep up with those 3 little main jets.<br /><br />-W (using same pump)<br /><br />And no there's no big secret.... I rarely check these boards on the weekends. And you already had everything you needed to email me for a phone number. In fact since you seem to know we sell a lot of powerheads, you should have my phone number already as it's on every ad. Troubleshooting takes good detective skills.

 

[Laddies]

Re: inline 6 fuel volume to low seeking help from clams

No big secret about marine fuel pumps, they are a simple as you can get, you simply had some bad facts and no one commented on them. If you want to get help from Clams or anyone else, its probably not a good idea to attack the integrity of those that anwser your questions--Bob

 

[webster101]

Re: inline 6 fuel volume to low seeking help from clams

sorry did not mean to upset anyone laddies.Im the one thats frustrated I apologize if I affended anyone being a auto technician with over 30 years expreiance things have to make sence to me and untill clams explained about the #3&#4 pistons working pump and are not affected by bottom crank seal it made sence that press and volume might be low due to leaking crank seal.thanks clams for the expertise and the explanation on this.when I bought the fuel pump overhaul kit it did not come with those 2 small valves.testing boat after replacing fuel pump gaskets motor still hesatated and died.since then i have replaced both valves and found that I probably had all the idle mixture screws set to lean(1&3/4 turns)have fattened up to 2&1/2 turns to start with.checked fuel pump press in driveway fuel press gauge does not fluctuate like it did before replacing valves and allthow press seemed low at idle(3 psi) did not run at W.O.T my gauge might not be accuate.will be going to lake this coming weekend to check if hesatation is gone.thanks again both of you guys(clams and laddies)I do plan on going threw and pulling powerhead this winter so hopfully did not burn any bridges as this is a great resource for an old has been 4stroke tech like myself.

 

[webster101]

Re: inline 6 fuel volume to low seeking help from clams

ok motor fixed after replacing 2 check valves in fuel pump that did not come in overhaul kit. thanks to all that responded and a special thanks to clams