Suzuki DT55 limp mode? Low RPM's

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

No, the middle piston isn't stamped. I did measure all the old pistons at the same place and the results were the same at 2.885".

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

Well I split the bottom end. Water pump impeller looks almost brand new. ... And that's the only good news.

I then started playing with the shift rod ... What a mistake. I pulled it too hard and the shift rod guide and o rings popped out of the drive shaft bearing housing. Of course I had the bottom end on its side in the vice (soft jaws) so stinky gear oil everywhere. I tried to push it back in gently to no avail ... Then to the manual. Looks like the return spring in the propeller shaft would have acted on the push rod to move it forward, thereby blocking the path for the shift rod to drop back into place.

I guess I'll have to pull the propeller shaft housing and propeller shaft assembly to facilitate relocating the shift cam behind the push rod.

My question is: can I just pull back the propeller shaft housing and propeller shaft assembly just enough to put things right, then push it back in place ... Or do I have to pull the guts right out? Man I hope I don't have to start digging too deep in there ... It's something I don't want to get into. Lesson learned.

Edit: I grow increasingly comfortable with the innards of the lower unit as I study the manual. I just noticed the spring and detent ball ... I'm sure that's causing me grief too ...

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

Well Suzuki Christmas has arrived by way of parts. I kept a list of all the parts that were missing during tear-down and ordered absolutely everything from spring-washers to clips to plastic plugs (that are purely aesthetic). If I am going to do this, I’m going to try and do a good job. I also had my lower end welded to replace the skeg that the previous owner “removed” … Before and after pictured attached.

More soon I hope.

 

[TwoRivers]

Re: Suzuki DT55 limp mode? Low RPM's

Skeg looks good.
Merry Christmas.
good luck
rob

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

Well I've decided to attempt to crack open the bottom end. One of the bolts that secure the propeller shaft bearing housing to the gear case sheared off *sigh* ... so the lower end is going to be heading to the machine shop too.

I see in the manual that I "need" a slide hammer to remove the propeller shaft bearing housing and the propeller shaft assembly. I don't have a slide hammer. What I do have is a chain fall and an assortment of straps. I used the frame of my 20 ton press to rig up something that I hope will work. I did my best to keep everything square and rig the strap on the shaft so the chain fall has a straight pull. I also applied a liberal amount of penetrating oil to the bolt holes and mating surface. I've got a fair amount of tension on the chain fall now and no movement. Makes me laugh that Suzuki recommends a slide hammer ... what a joke. There is no rush for this, I can come out each day and add a few clicks to the chain fall, I’m confident it will pop out eventually.

Anyone have any comments regarding this set up? Good idea? Bad idea? Sure wish I had oxy acetylene to put some heat into that gear case … might have helped with all the sheared bolts in the power head too haha.

 

[99yam40]

Re: Suzuki DT55 limp mode? Low RPM's

the shock of the slide hammer and heat is needed to move it a little at a time.

If you put enough tension on the chain fall and it finally turns loose it may fly up and damage something

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

Thanks 99yam40. I'm less concerned with possible damage resulting from the "popping free under tension" and more concerned with the damage I could cause to the bearing while pulling. What are the chances I could damage the bearing before the housing starts to move?

What a mess, all because I was playing with the shift rod. Too bad Suzuki didn't design it with a threaded shift rod guide and dust cap ... then you could pull on it all day and it wouldn't pop out. I think I'll leave the tension on it over night. I'm going to head out now and pour some oil in the through the exhaust holes. Hopefully it will find its way to the propeller shaft housing o-ring. That way even if it moves even a fraction of an inch, it will then be riding on lubrication of sorts.

 

[99yam40]

Re: Suzuki DT55 limp mode? Low RPM's

that welding on the lower unit may have melted the orings and seals if it was not taken apart while doing it. probably not good on the oil also

corrosion may make it a must to have heat to break things loose

does the manual call for pulling on the shaft or the housing?
The only Suzuki I pulled the housing on was a DT150 and I think we pulled on the housing not the shaft, but that was years ago, so I am not sure

good luck on your repairs

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

The manual calls for pulling on the shaft.

I can almost guarantee that the seal is gone because much of the oil leaked out of the shift rod seal while the lower unit was clamped into the jig for welding. This would have done nothing for heat dissipation.

I know someone with oxy acetylene bottles, I've just never done this before.

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

I abandoned the chain fall, it wasn't working. I got a quote of $90/hr and an "it takes as long as it takes" explanation from someone quite rude over the phone. I decided to visit a friend and give the oxy acetylene a go. We had a side hammer designed for removing dents from cars. We were able to "Red Green" it onto the propeller shaft with hose clamps. Heated the gear case and after a few whacks with the hammer she came apart. All gears have no visible wear, looks good in there. I'm going to do the inspections on everything as per the manual, but I think the biggest job now will be cleaning it up before reassembly. I had the power head with me and using the oxy we were able to remove most of the broken studs, 3 remain that need to be done professionally. We also removed the broken bolt that sheared off the lower unit. Pics to follow, was a long day I'm beat.

 

[99yam40]

Re: Suzuki DT55 limp mode? Low RPM's

sounds like you are gaining some very good experience
manuals are a good thing to have along with good friends with tools and equipment

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

Photos as promised. Nothing has been cleaned.

Here is the gear case. I’m not pulling the spring collar or any of its associated components.

Here is a shot of all the internals together. The spring and detent ball were indeed rolling around inside and fell out when I up-turned the gear case after the propeller shaft housing was removed.

Here is a close up of the shift cam. It looks to be in good condition with minimal wear.

Here is the forward gear (and bearing underneath).

Pinion gear.

Reverse gear, clutch dog and propeller shaft housing with the offending o-ring.

I’m so happy this is apart. Next step is to have those three remaining bolts drilled out, deglaze/light cross thatching of cylinder walls and have everything cleaned up.

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

A new dog clutch is cheap, like $60. Should I replace it? I need to place another order soon so it's no big deal in that respect. What do you guy think?

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

Hi all ... long time no talk.

I sent out the head for broken stud removal etc ... I had the cylinders deglazed, two heli coils installed and all the parts either media blasted or cleaned up in an industrial washer. Turned out good. Now the fun begins ... rebuild!!

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

Finally some progress in the right direction this evening. New pistons, rings, wrist pins, small end bearings and circlips assembled onto the existing crank shaft. New crankshaft lower oil seal installed. Two new lip seals installed into the lower oil seal housing and a new o-ring on the lower oil seal housing. I used a lot of oil for reassembly. Here are some pictures.

I?m hoping to get more done tomorrow.

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

More progress today. I buttoned up the crank case, installed exhaust covers, installed the cylinder head and cylinder head cover, tested and installed the overheat and start-up ignition timing sensors, installed thermostat, installed magneto case/flywheel and gear counter coil, rebuilt and installed fuel pump, installed oil pump, tested and installed oil flow sensor, installed starter, installed staring motor relay, installed PTT up and down relays then closed out the day by wiring up the CDI unit and connecting a lot of wires back up.

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

Was only allowed 6 photos per post … here are a few more …

The head is ready to drop into place and bolt up. I want to finish rebuilding the lower end first so I can make the shift rod connection more easily, and then install the head. I have to order new thrust washers before I can button up the lower unit.

 

[99yam40]

Re: Suzuki DT55 limp mode? Low RPM's

without paint on all of those outer shiny surfaces there will be a lot of corrosion

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

I have zinc chromate primer and suzuki charcoal grey top coat ready to go. I just have to do it ... Easy to pop off the CDI and trim relays, mask off the motor and hit it with some paint. It's too damn cold to paint right now where I live (-1 degree celcius right now). I couldn't help myself ... I had to keep building, I was on such a roll.

 

[Big_worm81]

Re: Suzuki DT55 limp mode? Low RPM's

Well I set up the heaters and went at it anyway … what the heck, everything was already sanded and ready for paint on the lower unit.

Wait a few days as per the instructions on the paint can and hit it with the Suzuki top coat.