Sugar Sand Tango 1998 175 Merc xr2

[ToesintheSand]

Hello to all! Newbie here, both too jetboats and the site. Hoping for some insight and ideas on my problem. Also hoping to find a member(from the old forum or another forum that guided me here?) called csm1992 as he had the same issue on his Tango.
Anyway, I took the boat out last Saturday and she ran great all day. No issues at all. I took it out Sunday and all was well until after I dropped my kids off at boat launch. We went back out and within minutes, she started bogging just off idle. We could run WOT and idle but zero mid range.....just kept stalling. Started right back up each time and would repeat the same problem. It seems like it would be a clogged needle jet problem, but my experience on this carb/motor is zero. I am familiar with dirtbike/quad two strokes and your basic Keihin carbs and have rebuilt many. I really can't think of anything else that effects mid range ONLY, unless a passageway is blocked.......
For now I am going to use some carb cleaner and some seafoam and take it too the lake to sse what happens.

 

[JC6275]

Welcome aboard!!!! I would change the plugs. Sounds like it could be a load / no load issue. Just a place to start.. also fuel filtets

 

[ToesintheSand]

Thanks JC !I will try that as well. I need to get spares anyway and I will check filters.
I'm hoping there will be no carb removal for cleaning...lokks like a pain..... : /

 

[JC6275]

I am not familiar with your specific motor but that's a good place to start on the 2 strokes ... Good luck, this forum has the cool feature of tagging @ToesintheSand . So you may be able to find the member you were looking for, if they have the same screen name as before

 

[Boat Crazy]

Welcome! Curious, were you by chance anchored at LOA behind all the Yamaha's at Aquapalooza? If so Very nice boat.

 

[ToesintheSand]

Wasn't me at LOA.....I'm in metro Detroit area sound like fun tho!!

 

[Bruce]

Welcome Aboard!

Sorry I not familiar with your engine but this is the closest experience that I have had - Seafoam Worked For Me

I would start with some simple things; change the spark plugs, change the fuel filter and add some sea foam to the fuel which may help clean the carburetor.

 

[Bilmon]

Welcome, good to see another SugarSand. Not real familiar with the 175 but I know they use 2 sets of coil windings in the stator[under the flywheel], one for low speed and one for high. From what I have heard they are a common problem on the older 175,s and can cause problems like you are describing. Replacement parts are supposedly improved. Procedure to test is in service manual you can find here if you don't have one; www.boatinfo.no

 

[ToesintheSand]

Thnx Bilmon. I will check out carbs and move on to electrical. It's weird that it will run all day at WOT or idle. But as soon as you start backing it down from WOT or pushing up past a high idle.......dead

 

[Kevin Turner]

Thnx Bilmon. I will check out carbs and move on to electrical. It's weird that it will run all day at WOT or idle. But as soon as you start backing it down from WOT or pushing up past a high idle.......dead

Was it cool, rainy, or humid when the fault occurred? If so, the problem could be oil & moist air emulsion build up in the carb throats. In between the carb barrels is a vent hole. Blow the vent hole clean then block off the tiny hole in the gaskets so the hole is open to engine box pressure only.

 

[Seadeals]

I had that problem on my prior boat (outboard). I spent a little too long trying to nurse it (seafoam, carb cleaner, etc...). The running time doing so damaged cylinder #3 which went to zero compression. The crazy thing was... it's last day on the water was very good, just a PITA to keep it running between idle and cruise RPM on the last start-up back to the ramp. Once I got it past that short RPM band, it ran like a champ (apparently on two cylinders). I still can't figure out why I did not notice a power loss or different noise; but it was a clogged needle jet which leaned the mixture at idle too much. Aluminum piston/steel cylinder coefficient of expansion burned me on #3. I spared myself the cost of an overhaul by selling the boat as is and buying my Yamaha (great move); but if you don't want a Yamaha and you have not rebuilt the carbs in a while, consider doing so even as a preventative measure. It is not fun (for most) to do yourself, or cheap to have someone else do it; but much better than rebuilding your whole engine.

 

[ToesintheSand]

It's been a mixture of weather. I have had this happen over a period of all weather. I have , in fact, cleaned the mid circuit vent hole and it worked......for a while. I have some electrical issues as well. I replaced one coil and got a new battery(due to excessive cranking after mid range stalling). Still had issues. In the mean time I have added some Sea Foam as well.....which goes against the "fix one thing at a time theory" . That was Labor Day wknd.
I took it out last Sunday and it ran throughout the whole range for the afternoon. It was nice to just drive the boat without issues ......gonna see again this weekend if it still does.
I have noticed wet oily residue on carbs and trying to keep it clean. I also have some electrical issues that dropped a cylinder and intermittent on another. I odrered parts from ebay for this and got shafted. 3 coils and a switchbox.....carbide was cracked on 2 of the coils and switchbox was wrong one.
I will go new now. Trying to diagnose this, with multiple symptoms , is proving to be a challenge.....and fall is rearing its head. Compression in all cylinders is 130-135 ish. I will probably rebuild carbs this winter and run her next summer until we figure out what other boat we want. I love the smell of 2 stroke on a sled, but we don't much like it on a boat. Of course, there's not much idling and no wake time on a sled

 

[Ronnie]

How did the carbs, specifically the needles look? I ask because I had a euroline cyclone with the same engine and pump. When it started running poorly I took it to the shop and they ended up rebuilding all three carbs. They showed me the needles and all three were deteriorating, they never saw that before and suspected it had something to do with the fuel additives back than. They got my permission to send the needles to mercury. The boat ran fine after that (and $500 to $600 to pay for that).

 

[ToesintheSand]

Haven't opened up carbs yet. I will be opening after this season. My gut has been needles/jets for that particular part of the problem. I want to run it this weekend to see if the issue repeats itself or runs fine like last weekend. Either way, I will be cleaning carbs. If Sea Foam loosened up anything , I want it outta the system completely !

 

[Kevin Turner]

Do you know the history of the craft? Older Merc fuel lines do not like ethanol. The lines look OK on the outside, however the inside maybe flaking.

As said above, lean can be very bad. I do a quick test that I don't recommend b/c of fire concerns (yikes, lol) However, it allows me to quickly catch a lean cylinder before she grenades.

I remove the air handler and hook up the garden hose. BEING CAREFUL!,I take many steps to make this a safe as possible.

I fire her up and momentarily palm the carb throats one by one. The high vacuum should draw raw fuel up and out of the carb throats. If I've a cylinder that does not flow as consistently as the others, I look for a stuck needle, fuel line failure, blocked passages, etc...

Of course this assumes reeds, compression, etc... is good.

In addition, being as I'm new here, I'll ask if the oil drive gear has been replaced or oil inj bypassed? Nothing to do with your issue, just wondering..

 

[ToesintheSand]

Kevin, the history is minimal on it. The guy I bought it from had it about one season and didnt do anything to it. I dont think he really got into anything but maintenance. I will pull fuel lines tho and look for any external fuel issues. Oil injection is stock , far as I know. I do need to clean up motor and then run, tho. Their is far more oil residue than I'm used to seeing.

 

[ToesintheSand]

Now that I think of it, the last time I saw so much oily wet residue on a 2 stroke was when the reeds were bad.....and you could see the mixture coming back out the throat of the carbs. I'll have to check that out too.

 

[Kevin Turner]

The early 175s were know for oil drive gear failures. If for any reason you hear an erratic beeping or unusual engine noises, I suggest shutting her down and dumping oil from your remote reservoir tank into the fuel tank. I've seen many failed power heads due to failed fiber driver gears. If ya post the power head serial number, I can check to see if Merc performed the fix. Or, your local Merc dealer can check for ya.

 

[ToesintheSand]

Here ya go ! I am also including a section from another post I had made about my electrical. It's below the pic.Since ya apparently work on these, please take a look .I 'm hoping you can tell me if I'm on the mark with my electrical issue. Or at least thinking right.



Electrical issue :
Holiday weekend at Higgins Lake and I have minimal time to fix this issue. I have 2 dropped cylinders on 1998 Powerjet 175xr2, narrowed it down to coils and switchbox....I think. Spark tested all cylinders and found that two bottom cylinders on left bank are getting no/intermittent spark. One is dead and one gets an occassional spark. Top cylinder is a nice strong blue spark at 7/16 gap so I switched good coil leads from switch box with bad coils to make sure it was coil related. The bad coils did not work with good wires...so I'm figuring 2 bad coils. However, and this part I'm not sure about, I hooked the leads from one of the bad coils, to the good coil.....no spark to good coil. So, is it safe to assume this is the switch box and not the trigger. I say this because each coil on the 3 coiled trigger is supposed to be for 2 cylinders- one on left bank, one on right. Because both my bad cylinders are on the left, I'm deducing that it's possibly a bad switchbox and 2 bad coils. Does this make sense ?? Or maybe it's something eniterly different that I am missing?
This motor runs and moves along ok, but I know it's supposed to be close to 50mph so I started checking stuff and this is what I found. Had I known Iknown i was only running on 4 cylinders I would have never kept driving it.

 

[Kevin Turner]

The drive gear was updated in Aug of 2000 / I've been working on SportJets for 15 yrs.

One thing I hope everyone will understand is my reluctance to diagnose electrical issues via the keyboard. Many, many times I've offered advice that didn't pan out. Sometimes because I was flat out wrong, but most b/c I failed to understand the info or I was given wrong info.