I'm back with a new problem

[Arkansan]

You guys have been so helpful to us over the past year that we've had this 98 Sportster 1800, and we've learned an awful lot about this boat. The week before last, we had it on the water five days in a row with only the most minor of issues that were easily solved. So today we had the courage to take another couple out with us... and things went wrong, of course. My husband and I are just baffled by this one.

Both engines started readily but with more white smoke than usual. (We always have white smoke when starting up.) When we got out of the no-wake zone after launching, we never could get the usual thrust. The RPMs looked normal, but we just weren't getting the speed. Never got above about 20 mph. We stopped to look around inside, and nothing obvious presented itself. When my husband went to restart, the starboard engine started normally, but the port engine just made a whirring sound when the starter button is pressed. No clicking, and the battery is clearly not the problem. The drive shaft moves fine when the plugs are removed. We decided to have our picnic anyway and swam and floated for awhile, then we limped back on the one engine.

My husband says it seems like something just disconnected, but what could it be? Is the solenoid bad? The starter? Any and all suggestions appreciated, as always. I took a quick video and will try to upload to YouTube so that you could hear the sound if you wanted. I'll post a link when I figure that out.

Thanks!!!

 

[Dr Honda]

if you heard a "Whirring" sound... that would be the starter spinning, but not engaging. I would start with checking the power cables. Make sure they are clan and tight. If that doesn't help... remove the starter, and check it.


As far as the speed... I'm not sure. But... you could have sucked up some junk, into the pumps. Have your checked them since putting it back on the trailer?

 

[1MACGYVER]

sounds like a sticky bendix gear to me, some models you can remove the bendix by pulling the starter out but on some you need to pull the front cover off the engine and pull the flywheel to get at it

 

[Arkansan]

We'll take a look at the pumps. Honestly, after the port engine stopped running, the lack of thrust became a secondary concern. Hubby checked everything obvious but has not yet pulled the starter. (We were running out of daylight.) We'll get started on it again this morning.

I know this is probably a stupid question, but is there an easier way to mess around in the engine compartment besides standing on one's head?

 

[1MACGYVER]

you can take the rear hatch off, bit of an effort but if youre spending much time in there it will make it easier

 

[Dr Honda]

...........

I know this is probably a stupid question, but is there an easier way to mess around in the engine compartment besides standing on one's head?

Nope. Boats kind of suck that way.

you can take the rear hatch off, bit of an effort but if youre spending much time in there it will make it easier

That does make it easier... but you are still hanging head down. AND... the deck lid is heavy, and easy to damage for a small project.

Removal for a full rebuild is OK... but I don't think I would do it for a starter. Heck... I just replaced 2 engines in a Challenger 1800 and left the deck lid on. (because I was by myself)

 

[Arkansan]

We aren't going to take the hatch cover off for anything. For anything that major, the boat is going in the shop! But we are trying to learn how to do DIY smaller repairs. I found a used, OEM starter on Ebay and went ahead and ordered it with expedited delivery because we have invited ANOTHER family to spend next weekend with us, and we really want the boat to be running by then. If we end up with a spare starter, that's not tragic.

 

[1MACGYVER]

what engines does the 1800 run?

edit: just looked it up, 720s therefore the bendix is part of the starter assembly not separate like the bigger motors, it should be a relatively easy fix compared.
You could also take the starter off and check/lube up the bendix and see if that sorts it while you are waiting for the new part

 

[Arkansan]

I thought they were 717s.

 

[Dr Honda]

I thought they were 717s.

717 cc = "720"

787 cc = "800"

947 cc = "951" (never figured out that one)

 

[Arkansan]

Oh, gotcha. Makes no sense, but gotcha.

 

[Arkansan]

For those who were kind enough to answer this: The bendix was completely sheared in two. New starter solved that problem, and perhap avoided having the same thing happen on the other engine because my husband discovered that only the two bolts are one end were holding both starters in place. The third bolt was missing from both, and my husband suspects that the previous owner or previous mechanic just gave up because the third bolt is so hard to line up and get in. But now that's done.

So both engines are starting like champs. One still doesn't like to idle. And we still have the thrust problem that presented itself even before the starter broke. We see nothing in the pumps. Gonna start searching around for possible answers to that mystery.

Thanks all!

 

[1MACGYVER]

Thrust problems usually stem from cavitation, you can get that from excessive gap between the prop and liner, foreign bodies in the grate-shaft-prop, air getting through the carbon seal or boot
Start checking through that area, if its air getting back from the hull to tube there is normally a second groove on the driveshaft that the clip can go in to tighten the seal, if it was an air problem you would normally see a bit of water coming back the other way at times

 

[Arkansan]

Thanks, MacGyver. We left the boat at the lakehouse and will get back to it next Saturday morning. My husband is learning more about this boat every weekend. We've been studying some pictures of the carbon ring that Dr. Honda posted awhile back and studying the shop manual. Maybe we can get this figured out.