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Catalina/Capri 25/250 Sailor's Forums

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Motor problems

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NautiC25
Admiral

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USA
957 Posts

Initially Posted - 02/21/2013 : 17:28:12

My Tohatsu, after 3yrs of flawless running, is now giving me headaches. It's a 1989 M8B 2-stroke. It all started when it decided to go dead on me on a really windy day. It wouldn't stay running at low speed and caused me to drift into the docks. 2 months later I am just now taking it apart to find the problem. At first, the crank wouldn't turn. I'm not sure what exactly that meant, but I'm not new to modern motors and know that isn't a good sign. So I removed the plugs and forced it around.
Now that I could crank it, it wouldn't start. Checked the fuel, and it was getting there. Sprayed carb cleaner in the intake and got it to fire up for 2 seconds, so I then knew it was the carb.
Took apart the carb as much as I knew how to. Basically removed the fuel bowl and 2 jets. Cleaned them up and sprayed cleaner in every oriface. Put it back on and it started right up! However, even after several minutes of warmup, I can't get it to idle at low speed.

I'm an EFI guy, and know nothing about ancient technologies such as carbs. So, I suspect there's a low speed jet or something clogged? Is there more than two, or is it the smaller one with several holes in it? What else can I clean up?

1989 C-25 TR/WK #5894
Miss Behavin'
Sittin' in LCYC on Canyon Lake, Texas

Edited by - NautiC25 on 02/21/2013 17:31:54

GaryB
Master Marine Consultant

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USA
4304 Posts

Response Posted - 02/21/2013 : 19:04:34

Not familiar with Tohatsu's but most all if not all 2 stroke outboards with a carb have a low speed jet. Sounds like your's has some trash caught in it.

I'd guess you're going to have to remove it, disassemble it, and soak it in carb cleaner then blow out every orifice with at least medium pressure air.

EDIT: Here's the parts breakdown for your motor -- >> [url="http://www.boats.net/parts/search/Tohatsu/Outboard/2002%20And%20Earlier/M8B/CARBURETOR/parts.html"]Tohatsu 8 HP Carb Parts[/url]

Edited by - GaryB on 02/21/2013 19:11:43

NautiC25
Admiral

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USA
957 Posts

Response Posted - 02/22/2013 : 08:46:42

That catalog is screwy. The carb is actually under the Magneto pic. lol
http://www.boats.net/parts/search/Tohatsu/Outboard/2003/M8B/MAGNETO/parts.html

I did a bit of searching and found that I could also try cleaning the pilot screw and it's hole. I'm just worried about screwing up any adjustments.

Edited by - NautiC25 on 02/22/2013 08:46:54

britinusa
Web Editor

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USA
5404 Posts

Response Posted - 02/22/2013 : 10:09:51

Not sure if it is applicable, but when I cleaned my outboard carb, I removed it completely from the engine, remove anything that had a gasket on it (unless it was unremovable without destruction) and soaked the carb in a tray of carb cleaner. Then used a spray can of carb cleaner to clean out anything that even looked like a jet. I did not make any adjustments to any of the jets at all.

After cleaning put it all back together and it ran like a champ.

And now I keep a healthy dose of fuel treatment in the gas all of the time.

Paul

Edited by - on

Derek Crawford
Master Marine Consultant

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USA
3321 Posts

Response Posted - 02/22/2013 : 16:16:44

Jonathan - if needed my 8hp electric start is for sale...

Edited by - on

delliottg
Former Mainsheet C250 Tech Editor

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USA
4479 Posts

Response Posted - 02/22/2013 : 18:40:24

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by britinusa
 Not sure if it is applicable, but when I cleaned my outboard carb, I removed it completely from the engine, remove anything that had a gasket on it (unless it was unremovable without destruction) and soaked the carb in a tray of carb cleaner. Then used a spray can of carb cleaner to clean out anything that even looked like a jet. I did not make any adjustments to any of the jets at all.

After cleaning put it all back together and it ran like a champ.

And now I keep a healthy dose of fuel treatment in the gas all of the time.

Paul
<hr height="1" noshade id="quote"></blockquote id="quote">

This is very similar to how I started fixing mine. [url="http://catalina-capri-25s.org/forum/topic.asp?ARCHIVE=true&TOPIC_ID=23379&whichpage=2"]I pulled rusty water off the bottom of a can of gas that'd gone through phase separation plugging my filters and jets[/url]. I ended up replacing both my jets & putting in a carb rebuild kit. My engine kept running badly & wouldn't run on the slow jet at all (below about 1800 RPM). This went on through three cleanings and soakings per Paul's post above. [url="http://www.catalina-capri-25s.org/forum/topic.asp?whichpage=1&TOPIC_ID=24772&"]Finally in desperation, I replaced the external fuel line & bulb, and the engine has run like a top ever since[/url]. I suspect the check valves in the bulb were sticking closed and would only allow gas to pass through them when the flow demand was high enough (throttle engaging the main jet & not the idle jet).

Edited by - on

NautiC25
Admiral

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USA
957 Posts

Response Posted - 02/23/2013 : 20:33:11

Well, I gave up and took it to a shop.

Edited by - on

Voyager
Master Marine Consultant

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USA
5378 Posts

Response Posted - 02/24/2013 : 19:25:13

Make sure to let us know what they found. It would be nice to know if it was bad gas, old gas that turned to gunk in the carb, the effect of E10 on your tank and fuel lines or just time for good cleaning.
In the fall I ran my fuel line dry letting the engine stall out. I pulled out the spark plugs and sprayed fogging oil into the cylinders. Wire brushed the plugs and put them back in. Let's hope that'll help come spring.

Edited by - on

NautiC25
Admiral

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USA
957 Posts

Response Posted - 02/25/2013 : 11:35:29

I just got the call. When I dropped it off, I told him exactly what the problem was. It starts instantly on the first pull, continues to run at half+ throttle. It only dies when trying to idle. That should have narrowed down the problem very easily for him right? Takes me less than 1 minute to remove the cover and carb to begin inspection.

Well, he says he spent "a couple hours", cleaned out some tiny jets that I didn't know existed, and that'll be $200 to clean out the carb passages. "Runs great!"

WTF!?!? Is this typical eye-gouging from a marine shop? I figured $100 max to clean a tiny toy carb. Especially after telling him exactly what the problem was.

Edited by - NautiC25 on 02/25/2013 11:37:02

Dave5041
Former Mainsheet Editor

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USA
3758 Posts

Response Posted - 02/25/2013 : 13:16:53

Reporting the symptoms is not quite the same as identifying the cause. I had it done 5-6 years ago with my old 2 cycle for $130 when I didn't have appropriate tools with me. Just be happy if the problem is solved. I had a similar problem this year that I thought was gunk but did't respond to a cleaning. With area shop rates at $100-110/hour, it cost $500 to identify and replace a cracked nozzle. Shop rates at home are $65-80/ hour. I certainly wished I had addressed before I left. The Sierra filter/ water separator I installed wouldn't have prevented my problem, but a Sierra or Racor is an easy install and a very good addition.

Edited by - on

delliottg
Former Mainsheet C250 Tech Editor

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USA
4479 Posts

Response Posted - 02/25/2013 : 20:13:35

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by NautiC25
 I just got the call. When I dropped it off, I told him exactly what the problem was. It starts instantly on the first pull, continues to run at half+ throttle. It only dies when trying to idle. That should have narrowed down the problem very easily for him right? Takes me less than 1 minute to remove the cover and carb to begin inspection.

Well, he says he spent "a couple hours", cleaned out some tiny jets that I didn't know existed, and that'll be $200 to clean out the carb passages. "Runs great!"

WTF!?!? Is this typical eye-gouging from a marine shop? I figured $100 max to clean a tiny toy carb. Especially after telling him exactly what the problem was.
<hr height="1" noshade id="quote"></blockquote id="quote">

[url="http://catalina-capri-25s.org/forum/topic.asp?ARCHIVE=true&TOPIC_ID=16332"]Don't get me started[/url].

Edited by - on

NautiC25
Admiral

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USA
957 Posts

Response Posted - 02/25/2013 : 20:48:11

Yea, that's pretty crappy. I probably would have yanked my motor out of there the first week. I have no patience for bad business.

I tried to ask him about a quote, but he said he had absolutely no idea until he "got in there". I mean, even a complete carb rebuild could yield some type of "worst case" estimate. Look at my link above. I could buy a whole new carb assembly for $164!!! Why would I pay more to fix an old one? I'll go in calm and allow him an explanation of the charges.

Edited by - NautiC25 on 02/25/2013 20:52:49

panhead1948
Captain

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345 Posts

Response Posted - 02/26/2013 : 16:08:14

Well I took my Honda in for a rough idle. They cleaned the carb,checked the thermostat,installed a new impeller, new plugs, and changed the oil. 310.00 I guess I got a good deal.

Edited by - on

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