90 tldi questions for Gure

I have a MD90b 03 model year the motor runs great but has some quirks I hope you can help me with. Iread your post about the 1000 cca battery and TPS resets.I installed new battery 1 yr ago not sure what cca it is but engine not starting very easy when cold but starts fine rest of the day. had battery tested and was told it was fine first thing I did was clean terminals could the battery be too small? It is a marine starting should I use combo battery? Next ,some times when I put it in gear the motor stalls and sounds and feels like the prop hit something. Took to dealer and he couldnt get it to do it and had no insight on what it could be. Next, the lower unit is cracking behind the propeller dealer said it was from corrosion between the lower unit housing and the ring with the 2 bolts top and bottom behind the prop. ASked him about having weld repair he said taking it apart would open a can of worms and it would be fine until it cracked into gear case grease leaked out then I could replace the whole lower unit is this good advice? Lastly, I have always De carbed my carborated engines yearly is this necessary with the clean burning tldi and if so how is it done? Thanks in advance

Re: 90 tldi questions for Guru

Re: 90 tldi questions for Guru

"could the battery be too small?"

Absolutely. If the battery is to small it cannot correctly initate the engine electronics which will cause:

Starting problems

Rough idle

No power

Etc.

"should I use combo battery"

I don't what you mean....Virtually anything that does two different things ends up doing nothing well. Voltage is important on DFI engines so choose the engine over any other criteria.

"replace the whole lower unit is this good advice?"

No...He's sounds like an idiot. Fix a problem as soon as you find it and you will avoid major problems down the road.

"is this necessary with the clean burning tldi and if so how is it done?"

It shouldn't be necessary unless the engine has had a problem. Carbon will not build up in a DFI engine unless it is sick or the wrong oil is being used. But, it won't hurt anything to pop the spark plugs and load up one cylinder at at time. IE Decarb each cylinder independently, on at a time. The only DFI engines I have ever seen that were badly carboned out were Optimax's. All due to the wrong oil or defective fuel rails.

Re: 90 tldi questions for Gure

For the lower unit, if it has not cracked into the part that holds the gear lube, find the very end of the crack and relieve the stress by drilling a small hole there.......1/8" or so. Before you do this it would be nice to have a good clean pic of where the cracking is occuring, the hole drilling may not be an appropriate fix.

Waylan

Re: 90 tldi questions for Gure

Thanks for the Quick response! By combo battery I meant starting/deepcycle . once the engine is started it runs fine but lately it just turns over slowly. The battery is marine starting 700cca. The cracking on lower unit looks to be from corrosion between the housing and the part that bolts on to the lower unit behind the prop have you seen this before? Any ideas on why the motor would stall like the prop hit something but only does it occasionally when put in gear is there some kind of clutch or synronizer and the dealer just didnt want to deal with it because of the cracking and opening a can of worms as the dealer put it. once again thanks for the input


Chris

How shallow will she run? shallow enough to plant corn behind her!

Re: 90 tldi questions for Gure

"The battery is marine starting 700cca."

Then its too small.

"have you seen this before?"

Common on old Suzuki's, rare on everything else. Probably an o-ring failure on the propshaft housing allowing a buildup of salt to occur inside the housing. The salt has to go somewhere so it ends up cracking the gearcase.

"Any ideas on why the motor would stall like the prop hit something but only does it occasionally when put in gear is there some kind of clutch or synronizer and the dealer just didnt want to deal with it because of the cracking and opening a can of worms as the dealer put it"

Stalling can be from anything. You strain the engine when you put it in gear and that causes the idle to fall down below what it needs to run. Could be electrical(see battery, wiring), might be mechanical(lower unit binding, powerhead problem or it might be fuel system(fuel, tank, fuel line, injectors, etc.)

Re: 90 tldi questions for Gure

As far as the stalling goes, i find that the tldi`s do that more than others, usually if you turn the idle up it helps, but they just do that. I think it is mostly due to the parasitic drag if the air pump and huge charging system needed to run the injection system.

Re: 90 tldi questions for Gure

once again thanks for the input. Iwill upgrade my battery, I had no idea a little 90 needed such a big battery. As far stalling I feel like it is mechanical because when it happens the motor stops very abruptly like it is binding or has hit something just cant figure out why it is so intermitent . The motor does hicup occasionaly when idleing in gear but does not stall .
Chevyjet your explaination might cover


this.

Chris

Re: 90 tldi questions for Gure

Just to add another data point, I have the same motor and same model year. My 90B tldi has never stalled upon putting it into gear in the six seasons (250 hrs) I've used it.

Mine did become hard to start when cold. Once it started, it would start fine the rest of the day. I have about a 20' run from battery to motor, and battery cables were joined to the factory cables to make the length. At Guru's suggestion, I elimated the two cables and ran one set of continuous heavier cables from battery to motor.