trying again

[mrdrh99]

Hi, was asking if you have speed tubes under big ones, most Cats have them, unless beeing a much simple new model. Have you fully checked transom's tech plate specs. Max HP and size S.L ? A 7.5 is just good for fast displacement speeds, near mission impossibel to plane, lacks power to get out of the hole. If engine runs 20:1 run it that way. 50:1 is too poor on oil for that probably old model. Expect to smoke worst than a indian tribe.... Happy Boating

Ok... I gotcha, no it isn't set up like the taka cat... They are very nice though. It's just like the other Sib tubes just cut up front like the other cats. However the floor is the same design, no keel, tubes on either side are lower than the floor so when on a plane the floor is off the water. At least that is how it was explained to me.

 

[Sea Rider]

Mrdrh,

Definitely, due to having more hull drag resistace to overcome fast hole shot compared to a standard sib/rib of that same size with same engine. Much worts if having lower speed tubes which isn't your case. Is that engine and prop in top healthy running conditions ? You could have a spun prop issue or in its way to having one, it's a veteran engine. Check.

That model sib needs to be top inflated, those floorboards have small side joiners which protrude out lower tubes and holds the floor deck in place. If not top inflated to at least 3.0 psi once sib rests on water, floor will slang and even could be disassembled from the position they were assembled when encountering choppy, wavy sea conditions.

That floor holding method is much faster to assemble, but has its performing limitations if sib is under inflated compared to tradditional wooden or alum side joiners.

Happy Boating

 

[fbpooler]

If that is the 1958 Johnson, it would not have shallow water drive and possibly not a neutral lock out. It definitely would not have come with a engine kill cord. Tilt pin position would have no effect on the engine being able to run.

Using the wrong fuel/oil mixture is sure death in that engine. Too little oil will cause galling of the square cross section rings in those old three piston ring motors and can result in broken piston rings. I do not remember Keystone tapered rings as being common in those days. Back when that motor was new, people used 30 wt, non detergent oil as the outboard oil we use now had not been developed. It smoked like the devil.

Hopefully when it froze up from lack of proper lubrication, you did no permanent damage. Often when overheated, the engine can be run successfully after cooling down and breaking the rings free, as they were tough motors. They did need carbon removal from time to time.

Many small motors of that era used bushings instead of ball bearings for the upper and lower mains. Bushings depend on an oil film under the bushing for lubrication, so if under lubricated, there is heavy bushing wear and expansion due to heat.

One of the old engines is capable of giving good service and darn near impossible to wear out if cared for. They overbuilt things during that period of manufacturing. Some antique motor fans actually run the old engines without piston rings, but that is destructive to the motors.

Be careful of advice from people not familiar with old engine design. They come from the day of pencil and paper calculations, not computers and safety devices..

 

[Guest]

@fbpooler, i hope you are not implying that i do not know what i am talking about. By the way thay 58 does have a neutral lock "Throttle Linkage : This linkage is rather different and complicated than you will generally see. The twist grip shaft has a small gear on the rear that engages a gear rack, so as you rotate the twist grip, this geared rack extends or withdraws. The rack shaft then engages a linkage plate that then engages another linkage plate, which ties to the timing plate. Rather complicated, but it works quite well. There is also a neutral safety lockout that prevents the motor's twist grip throttle from being advanced past the "START" position. This is simply a rod connected to the internal shifting linkage that abuts against a flathead screw from the twist grip linkage. This screw can be adjusted. However you can shift into either forward or reverse, then twist to a higher setting to start it." Please refrain from negative comments. @mrdrh, Well that model does have a lock but i do not think it would affect you trying to pull start. It would affect you able to put the outboard into gear. So rule out that issue. Most of my outboard work was done on mid 90's merc 6, my 06 4stroke and my newly acquired 1992 2.5 hatsu

 

[Guest]

Oh and by the way that motor does have a shallow drive. It had a manual shallow deive bracket that. An be adjusted in shallow waters

 

[fbpooler]

http://www.marineengine.com/parts/j...manufacturer=Johnson&section=Lower+Unit+Group

That is the lower unit on that motor which only has four position tilt adjustment and no shallow water drive assembly. Lack of lubrication is deadly on those engines. They carboned up readily due to the oil and would break piston rings from the carbon deposits if not cared for. I rebuilt a 1951 Evinrude and had to have a friend make a set of rings for it,

The gear type throtle control was common to many Johnson and Evinrude motors for years. Many could be started in gear which was the cause of many mishaps but came in handy when trolling.

That engine used shear pin drive and the most common problem was damaging a clutch dog. A locked up lower unit would be unusual.

After the mid 90's, motors incorporated many features which were not available in the past.

Giving the gentleman an insight to the older motor designs is not the wrong thing to do, as it could prove to be helpful to him. He had a simple problem which hopefully did not do severe damage to the powerhead. If he galled metal or broke a ring, it will require rebuilding though. I would run a cylinder pressure test, and if it appeared to be within range, it could probably be put back in service using break in procedures until assured it runs correctly..

 

[fbpooler]

I am going to double post for a change, but maybe it will help with problem solving. The tendency is for a person to feel a problem is more complex than it is, sort of like not seeing the forest for the trees.

Overthinking a problem can be misleading, and we all have that fault. I have seen equipment cause very expensive problems which generally turned out to require a very simple solution. A two stroke engine is a simple device, but it is unreal how many good mechanics will balk before working on one. One of the first things people do when they run into a problem is to go through what I call "what if" thinking and complicate the issue.

Here we have an engine which is running and then locks up. Yep, something probably broke or seized, so you want to go over it with the most common problems investigated first. A locked up power head and probably heated parts is the first thing to check. Gear box problems which lock up a motor are seldom encountered and should make their presence known before actually failing. by being hard to engage with possible vibration.

In this case we have a motor of an older design which does not have a lot of mechanisms bolted on. After going through a cooling cycle, it was possible to break it free and turn the engine over. Any internal damage which occurred is impossible to determine without tearing it down, but lack of lubrication should be the first item investigated. It was designed long before TCW and other lubricants were invented. There is a good possibility that this motor will require rebuilding, but sometimes the damage is minimal enough that it will wear back in if parts were not broken when it froze up. If the aluminum piston skirts expanded and galled, they may wear back in. If the cylinder walls were scored or rings broken, it is rebuild time.

 

[mrdrh99]

My motor guy is back... He has a 1988 14hp rude. What kind if performance could I expect out of that?!