Does this sound like a fuel problem...

[gcha1727]

Twin 787s. 1st motor is fine. 2nd motor...

The carb was adjusted to 3k on trailer 1.5k in water. The motor was just rebuilt, reinstalled, compression near 150 in both cylinders.

Now when I start it cold on trailer it runs at 2k rpms for about 10 seconds then kicks up to about 3300 after 10 seconds (roughly). It seems to stay there, I shut it off after about 15-20 seconds.

On the water, it idles around 1200 rpms and sputters sometimes. Upon acceleration sputters and bogs. rpms are lower than other motor at any throttle position. At 1/3 throttle only 2kish and at half throttle around 3.5k rpms. The other motor is around 4.5 at half throttle. Full throttle on bad side will push to 4.5k.

The weird thing is at times is suddenly engages . The rpms kick up to pretty much match the good side. A couple times at or near WOT the bad side kicked in but only to around 6200rpms. It would hold there for maybe up to a minute , then sputter a bit and then back to around4-5k rpms.

The sputtering sounds only occur when its tryin to engage to the higher level of rpms.

Any ideas or comments???
Thanks

 

[seadooya]

make sure you got new spark plugs and that the raves are clean.

 

[gcha1727]

Yes the plugs are new. The raves were done a few backs before I rebuilt motor.

Also I cleaned carbs about 1-2 months ago. No gray lines...

 

[gcha1727]

The raves were done a few weeks ago

 

[seadooya]

takes a second, to check the raves. Remove caps, and pull up on them. Had it where, i cleaned mine, for the one to be completely stuck after 2hrs of use.

 

[gcha1727]

Thanks seedooya. I will have to check in morn...its dark out here.

Does it sound like a poss fuel issue to you also??

 

[seadooya]

sounds like a rave issue. Once at high rpm, with a stuck rave, you'll kill the spark plug, then you wont get no moe than the 4-5k rpms, your get'n, but could be fuel issue.

Just though of something, fire boat up, bad motor only, and hold steady 5500rpm, get voltmeter/mutlimeter, and probethe battery. Your readings should be in the high 13's/low 14's, if in the 12's or 15's, then your problem with everything, is the rectifier.

 

[gcha1727]

I will check the voltage also. Id go look now but the damn mosquitos put up a good fight after dark

 

[gcha1727]

Today I checked voltage thru the motor as suggested and it checked fine. Also the raves were just a bit oily as usual. No prob there.

Also pulled carb off checked filters they still look good. cleaned them anyway. Sprayed a bunch of carb cleaner thru carb. I was not able to get the 4 screws off plate on high speed side to run cleaner thru it. Maybe I need to soak it to help loosen them. I did spray alot of cleaner at high speed jet the best I could.

Went back to lake today and the idle was low. sputtered a bit at the dock. Tryin to make the best of it, I left dock and stalled repeatedly and was difficult to restart. Its the worst Ive seen it yet. Finally it stayed running...barely... but again only to 4-4.5k.

About 30 minutes into trip it finally popped up to 7k. I ran it almost full throttle for almost 5 minutes. Best 5 minutes ever on the boat!!! but then when I backed off the throttle...same crap. Although a few times shortly after that the rpms would engage as it should but never for too long.

Also I figured out if I start my good motor 1st, then put it forward, then put throttle HALF WAY on my bad motor and crank it had a much easier time to start.

 

[seadooya]

check it out bud. Just got from lake, testing same boat. Come to find out, whoever my customer, bought the boat from, messed with the panhead screw, that "sets" the "throw" of the excel pump arm.

Have your g/f-wife, move the throttle levers to wot, while your looking at the excel pump arm. Make sure that the "chrome" rod is in fact, depressing, into its housing, and most of all, makes sure its depressed, in the same amount. My customers stuck out some. Anyway, if this is the case, the "squirters" aint squirting, when actuated. Remove the airbox assy, and turn that panhead out (loosen), which will allow the arm, to "throw" more. Check it out, and post back.

 

[seadooya]

Also, make sure lsa/hsa are set correctly, had them set to lsa 1, hsa 0, idles set, then give shot. If still acting up, and the excel arms are coorect, switch over the water regulator, from the good side, to other, see if then, good side acts up.

 

[gcha1727]

ok..now were getting there

I checked out excel pump today and it was set as manuel shows. upon moving throttle hissing sound was heard through jet. I looked in carb hole and seen a dribble of fuel coming out.

Then I pulled other side apart to compare and the pumps were moving identical but the good motor was shooting more gas. Like a spray

Then I pulled the fuel line off carb, were it 1st comes into the mag carb. A lot of fuel poured out of the line so Im assuming its gotta be getting clogged in carb.

Also the mag side HSA screw is all jacked up, very hard to turn so I cant tell were its adjusted to.

And yesterday I was able to clean some of carb but obv not the right parts.
So it seems like were close to fixing it.

Do you think its that screw or something else???

Thanks

 

[gcha1727]

correction to earlier statement

Its my LSA screw on the mag carb that is locked up. I just unbolted carb from motor to spray the LSA with some PB. My HSA are centered , I assume thats the 0 position.

I swapped water valves a few months ago checking a different issue in which both valves were working well. Didnt think it mattered now, but thought Id mention it anyway.

You think if I get the LSA to turn it might fix it?

Thanks

 

[gcha1727]

day #308 without a working boat...time for insurance job

The idea of idling out(since this pos doesnt run correct)with the plug removed sounds better each day. I might get a little further from the dock if I nail a sail on it. And yes, I would use a friggn nailer

Unfortunately for me, by morning Ill have myself talked into another beating.

Anyways, if anyone would like to offer some insight...heres where im at.

With the help from seedooya, pretty much determined theres a fuel prob in carb. Today I took apart carb. In mag carb I found alot of tan crud inside. Mostly on and under diaphram. I took my time getting it all out. with my pick it looked like bread crumbs as it scraped off. Also diaphram had small hole in it .I replaced it with new one. pulled check valve and cleaned. I sprayed alot of cleaner through both sides. Watched it blow out holes easily. Soaked gaskets and filter in soapy water then gently rubbed em clean. lever in right location.

In pto carb pretty much seen samecrap but less of it. All gaskets were in good shape but cleaned them anyway. Took it all apart like mag side to clean. Lever set good.

I did not take off accel pump while doing this cleaning. Probably a big mistake.

Put the carb back on motor with no improvement. I was sure with all the crap i cleaned and the replaced diaphram it was gonna be fixed. After that I pretty much swapped everything between carb and fuel tank with the other side and it didnt help. Then I put the bad carb on good motor which did verify the problem is in the carb.

Also by soaking the LSA screw in PB I was able to get it moving and adjusted it.

So if the internal of carb is clean along with gaskets and filters is it in the accel pump somehow???

Anyone with an idea??? Or a sail you can part with...

 

[seadooya]

the excel pump, buddy is CRITICAL. Theres a check valve inline, from carb to pump, then a ball check inside the pump as well. Need to pull it and go thru it.

 

[gcha1727]

Is the check valve the part on the fuel line that looks like a mini filter?

 

[seadooya]

yup......along with a "check" inside the line, from carb to pump. Then theres a steel ball, inside the pump assy, that can get clooged.

 

[gcha1727]

will carb cleaner free em up?

 

[seadooya]

it should, but the "ball check", if stuck, will free with air or a small allen wrench, along with carb cleaner.

 

[gcha1727]

I found this metal piece/fitting inside the line in pic. That is the accel feed line I think. Is that piece suppose to be in there. The hole in it tiny and can barely blow air through it.

 

[seadooya]

yup........

 

[gcha1727]

ok. sorry for so many questions...

Should I be able to blow air through both these parts easily? With compressor it blows out cleaner no prob but if I do it not so easy.

Thanks

 

[seadooya]

no worries

you remember what way, they came out? Its there, to keep the flow/lines "primed". Would think, whatever way it flows easier when airs' presnt, then that side/way, should go toward the pump.

 

[gcha1727]

yeah theres an arrow on valve to show flow direction. 0 flow in wrong direction. goin the right way I can only pass air with compressor. I need compressor to pass air against ball check also. This is after alot of cleaner. Sound about right ???

 

[gcha1727]

Im not gonna say its fixed yet...

But it seems like it. Put it back together and with a little adjusting Im 3k on the trailer. Quick fire every time. Later today Im gonna take it to the the lake and see how it does.