Tohatsu 2004 40hp question?

[TOHATSU GURU]

Re: Tohatsu 2004 40hp question?

That begs the question...Why didn't you address it through your local dealer while in warranty? I'm not picking at you, I just hate to hear that you had a problem and didn't let your local Wizard spend Tohatsu's Yen to figure it out and correct it. The jets are good up to 5000 feet so that's not the problem. You could have a piece of trash in there from the day you have had it, but that's unlikely too. There is a rough spot in the RPM around 1650 RPM when the engine transitions from the Slow to Main jet. But, that only occurs within a 50 RPM powerband. The engine is not running lean if you are getting fouled plugs. Again, look at your carb settings and see if you are too rich, see if they are in sync, check your fuel pump diaghrams, check for a leak in the fuel lines, check your reeds. If all of those are okay then check all of your ignition components. If you still can't find the problem run it to a dealer. (I'd do that first, but if you want to spend the time yourself)

The idea with troubleshooting an engine is to start at what is most commonly wrong and work outward from there. There are a lot of things that can be wrong, but almost never are. If you waste your time starting at the wrong end of the problem chain you can spend an awful lot of time and money to find out it was a piece of casting hung up in the carb. That's not to say that you couldn't have a rare problem, but we call them RARE for a reason. Look at it this way: If you go to the doctor for a runny nose does she stick her finger up to check your prostate? No, she tells you to drink lots of beer and take lots of naps. We do the same in mechanics. If your engine is running rough we tell you it's probably your carburetors, because that is what it usually is. Always keep it simple and save the oddball and bizzare possibilites for last.

 

[james082273]

Re: Tohatsu 2004 40hp question?

Yep no doubt I should have addressed it with a dealer before the warranty ran out. I contemplated it, even called around a bit. I couldn't really bring myself to do it.

I was just hoping to get some possible experiences here in the forum that might point me in the right direction. I am noting Motions advise but I won't be swapping jets first. I am hoping to find something obvious like a piece of trash, bad float or needle/seat.

The plug fouling is strange really. There is no noticable fouling from a rich condition but when I swap them out it always runs better. The idle is no better but the mid rpm lugging will not have that missfiring pop/banging.

Got a question for you though 8) what is the likely hood I will I need a new kit just to open the carbs up and take a look?

 

[TOHATSU GURU]

Re: Tohatsu 2004 40hp question?

Zero. We sell tons of carburetor kits to people who use them as preventive maintenance, but usually everything could be cleaned up without needing to replace anything. If you don't mine me asking, why did you have a problem with ordering it through a non local dealer? The warranty wouldn't have been affected.

 

[MOTION LINE]

Re: Tohatsu 2004 40hp question?

Also possibly related it will [colour=null]foul a plug [/colour]when run at around 3000rpm possibly a little lower speeds. Hard to tell since I do not have a tach but it is just enough to keep the boat on plane. It typically will give a "banging/popping" sound until I speed up slightly just with old plugs.[colour=null] With brand new plugs it does not do that.[/colour]

In my opinion you have to much fuel compared to the spark, that could be because you have a weak spark or rich mixture

 

[deejaycee_2000]

Re: Tohatsu 2004 40hp question?

Nothing new here. Just some some known racing adaptations that you need to make if you are going to exceed the top RPM on any multipiece crankshaft. I'm not sure why this fallacy about Tohatsu crankshafts keeps being brought up. As long as you operate the engine in the recommended RPM ranges you will not have a problem with a crankshaft turning out of spec. ONLY using a Tohatsu in racing applications will twist crankshafts or if you have a catastrophic high speed stop. I don't profess to know everything in the world about Tohatsu's...But, what you can do to an engine for racing applications is not something that should be recommended for consumers to do to their pleasure engines. Let me know when you get to something I don't know.

Sorry TOHATSU GURU I can't resist " Let me know when you get to something I don't know" ..... I don't wanto step on your toes, cause I know how you feel about your motors, same as I feel about my Yamaha's (it is good, one has to have a passion for something, so i'm with you) ... but here goes .... We modify the yamaha's exactly the same as the tohatsu's and the yamaha never / hardly ever gives any problems .. neither will it ever snap a crank or melt a piston ...... why would you think that is? ..... Here is the specs according to how we are allowed to modify (motion you'll enjoy this) .....

MODIFIED SPECIFICATIONS
Propellers/Jets are free.
Re-boring is allowed up to a maximum of 849cc (1mm oversize maximum on pistons)
Bullet or racing gearboxes are allowed.
No restrictions on welding of the crank.
No restrictions on dimensions quoted.
No restrictions on weights quoted.
Measurements not quoted in the homologation sheets may be altered.
Parts may be changed with another manufacturer.
Holes may be drilled or cut into the exhaust trunk, but no external appendages may be added.
No protrusions other than standard are allowed.
No protruding expansion exhaust box.
Motor cowlings may be altered to increase air flow.
External water pick-ups are allowed

Intense hey?

 

[John_S]

Re: Tohatsu 2004 40hp question?

I don't own a 40D or other multiple carb outboard, but isn't a poping noise more indicative of a lean condition?

 

[james082273]

Re: Tohatsu 2004 40hp question?

Zero. We sell tons of carburetor kits to people who use them as preventive maintenance, but usually everything could be cleaned up without needing to replace anything. If you don't mine me asking, why did you have a problem with ordering it through a non local dealer? The warranty wouldn't have been affected.

Lets just say I could never get that "warm fuzzy feeling" talking to anyone in this area. I even had a shop deny they were even a tohat service center when they clearly advertised they were. I think it would have been much diifferent if I could have had the place I bought it from check it out whether it was a Tohatsu, Nissan, Johnson, yamaha, or whatever. I think these guys around here have plenty of work.

BTW- To protect everyone's interests I edited my post, sorry didn't mean to affend anyone!

Thank you on the info on the carb kit. I'll likely check them out this weekend. I did buy my service manual from you and will likely get a water pump kit this winter as wel. Thanks!

 

[TOHATSU GURU]

Re: Tohatsu 2004 40hp question?

deejaycee_2000,

Like I said..." Let me know when you get to something I don't know". I'm not sure what your point is. I haven't said anything negative about Yamaha. You have done nothing but denigrate the Tohatsu name since you started posting. What's worse is you don't appear to realize just how limited your knowledge of outboards really is. It's not your fault I suppose. Racer's rarely know anything outside of a particular model they themselves have raced. And I'm sure you do believe what you say. The problem is that there are lots of models of Tohatsu's used in a lot of applications where your limited racing experience has little bearing. If I had a question about cat racing you might be a source I would go to. As a source for information about outboards...You haven't said anything that isn't slanted beyond belief. You said in another post that your local Tohatsu dealer hates you. I think I understand why. Anyone who reads your posts probably does as well. I would strongly urge you to find another target for your petty crap as I am tired of it.

 

[TOHATSU GURU]

Re: Tohatsu 2004 40hp question?

A lean condition on a carb will often make a popping sound, however, if the engine was running lean it would still make the popping when he changed to new plugs. Since he said it goes away then, I would guess that in this case I think the popping is a miss due to other causes.

 

[John_S]

Re: Tohatsu 2004 40hp question?

Elvin, I can't explain that either. Can't say I have ever had popping/backfire from too rich or oil fowled plugs. Engine miss, but not popping. All of my outbaord experience comes from 40hp and less engines. All have been single carbed engines. Syncronizing carbs is not a pain I have had to endure yet. Anyway, look forward to following saga to the resoluton.


Racers, I enjoy reading about your experience with racing these engines. It would be best to just start new threads, though. It is very hard to see how twisted cranks have anything to do with this issue. Yep, its easy to get sidetracked in other discussions. I don't picture Nissan/Tohatsu as a state of the art engine with any direct support to racing. I have always pictured them as a no-frills, basic, well built engine that could save you $$ over the other guys. OK, now I'm getting sidetracked. Anyway start another thread and we can continue discussing....

 

[deejaycee_2000]

Re: Tohatsu 2004 40hp question?

deejaycee_2000,

Like I said..." Let me know when you get to something I don't know". I'm not sure what your point is. I haven't said anything negative about Yamaha. You have done nothing but denigrate the Tohatsu name since you started posting. What's worse is you don't appear to realize just how limited your knowledge of outboards really is. It's not your fault I suppose. Racer's rarely know anything outside of a particular model they themselves have raced. And I'm sure you do believe what you say. The problem is that there are lots of models of Tohatsu's used in a lot of applications where your limited racing experience has little bearing. If I had a question about cat racing you might be a source I would go to. As a source for information about outboards...You haven't said anything that isn't slanted beyond belief. You said in another post that your local Tohatsu dealer hates you. I think I understand why. Anyone who reads your posts probably does as well. I would strongly urge you to find another target for your petty crap as I am tired of it.

Damn, I was never rude to you, but it makes sense to me that when you feel challenged by a stronger person one gets offensive ... that is what competition is all about I geuss .... I didn't say you ever dissed yamaha, I have never dissed Tohatsu, but when I ask about the reliablilty vs makes of motors I get rude replies like this, although I don't think you ever see my true intent in my qeustions which is never negative .... anyway .... beyond belief is what I am all about, this is South Africa after all, pushing the laws of nature trying to do what no man has done before makes life more interesting and is a hell of alot of fun, you should try it sometime ... only reason the tohatsu dealers hate me is because my sponsers ended their contract and they lost out on alot of $$$ blaming me ... anyway, my knowledge of outboards and racing goes way beyond you'll ever have ... and just remember petty crap to you might be major to other people ... if you are sick of my postings, don't read it, there are many people on this forum that enjoy reading about the crazy things I get up to ....

 

[TOHATSU GURU]

Re: Tohatsu 2004 40hp question?

And your belligerence continues.

 

[james082273]

Re: Tohatsu 2004 40hp question?

Update!:'(

I am waiting on the factory service manual but had some time last night so I went through the carbs. All looked good, super clean actually. Floats are not adjustable and were fine. Reeds all looked intact. Fuel pump diaphrams were fine. Hopefully the manual will have the proper way to sync the carbs and will do that before heading back out to the lake. So nothing obvious yet.

I was a little surprised to see the oil is actually mixed with the gas before it enters the carbs. didn't think it was like that..

 

[Johnshan1]

Re: Tohatsu 2004 40hp question?

Hey guys I have the exact same engine only mine is marked as a 2003 40.

I have the same problem, at an idle it acts like it will lose a cylinder, has done this since day one, I asked the question a couple years back and got "its the nature of the beast". It is quiet at idle and then all of a sudden its vibrating and making a bit of noise, a tap of the throttle and its gone for a few seconds or so. I could never figure it out or get it any better, i think it is the nature of the beast.

 

[Johnshan1]

Re: Tohatsu 2004 40hp question?

New plugs or not I still have my problems by the way, but not any fouling at speed. I really think your on a witch hunt as mine does the same since day one. I will see if I can find my old thread about it.

 

[Johnshan1]

Re: Tohatsu 2004 40hp question?

Here ya go:

http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=34;gtid=1026880;gpid=1026893#gpid1026893

 

[Johnshan1]

Re: Tohatsu 2004 40hp question?

Also I noticed you mentioned your problem at that time too in that thread! Guess neither one of us has made any progress.

 

[Herra Raana # 1]

Re: Tohatsu 2004 40hp question?

Yes indeed that really is the nature of most of those beast, I have owned several 40ies only 1 ran perfectly from the box, I rushed them all to MOTION LINE who fixed the lean condition in the carbs (not so simple as one might think). My buddy ran his engine at idle or a little bit above and destroyed his pistons.

 

[james082273]

Re: Tohatsu 2004 40hp question?

Also I noticed you mentioned your problem at that time too in that thread! Guess neither one of us has made any progress.

8)8)8)8)8)

I have posted a few times in here since I bought it but I forgot about this thread. I'm glad your still hanging around!

I get the urge every now and then to check her out but I finally decided to do it once and for all. I guess all I can do is try! I'll keep posting as I go along though I am not likely to fix it.......

 

[TOHATSU GURU]

Re: Tohatsu 2004 40hp question?

James,

Do yourself a favor and call Tohatsu at 972-323-6003 and ask Keith or Alan about you engine. Some of the information being desiminated on iboats is now so far fetched that I think a little reality check would help you.