1998 GXT Limited 951 is dead

[3beers2many]

Well our weekend of fun was interrupted when my 951 deiced to throw a rod (It had 300+ hours on it). So now I'm kinda torn as far as what I should do for a new motor. I have read a lot of bad things about the SBT engines... Even know it seems to be the easy way to get back on the water I don't want to end up in the same situation after 20 hours of use. I guess I'm looking for alternatives to SBT so do any of you know of a reputable engine builder? Or does anyone have a low hour 951 for sale? I'm also up for opinions good or bad about SBT.

On a side note my current block now has about a 2" hole in it, I know it can be welded but are there any cons to fixing a blown out block?

 

[fireball451]

As long as it hasn't gone through any gasket surface, it can be repaired.
I went with SBT so I could get back on the water fast.
Their warranty is great.
So far, things have been good to go with their motor.
They quickly took care of a minor problem for me.
As far as the negatives about SBT, I chalk it up to you can't please everybody.
I would guess that many of the negatives may be from people blaming the SBT motor for blowing and they never found and corrected the problem that blew the original motor.
Don't think a company would survive and grow to their status if they sold alot of junk.....
I'm not sure.
I know I have had a good experience with them so far.

 

[3beers2many]

As long as it hasn't gone through any gasket surface, it can be repaired.
I went with SBT so I could get back on the water fast.
Their warranty is great.
So far, things have been good to go with their motor.
They quickly took care of a minor problem for me.
As far as the negatives about SBT, I chalk it up to you can't please everybody.
I would guess that many of the negatives may be from people blaming the SBT motor for blowing and they never found and corrected the problem that blew the original motor.
Don't think a company would survive and grow to their status if they sold alot of junk.....
I'm not sure.
I know I have had a good experience with them so far.

Thanks for your input fireball, I agree that the source of the problems needs to be identified. You make some good points about SBT, it's always good to see some positive feedback. I'm going to continue to look at my options and hopefully make a decision by the end of the week... Anyone else have an SBT experience they would like to share (good or bad)?

Now to address the main problem...

1. Possible oil pump failure.
2. Fuel delivery/carb problem. (I still have the grey fuel lines... Yeah I know they will be replaced).
3. Cooling issue.
Is there anything else I should be looking at? keep in mind the 951 had a lot of hours on it however the compression was still good.

A few questions:

Are there any cons to removing the oil pump all together? I see a lot of you with two strokes have done it.

Also should I go ahead rebuild my carbs since I have everything torn out?

Will I need to remove the pump assembly in order to use the “shaft line up tool” when I put everything back together?

Sorry for all the questions but this is my first ski rebuild and I want to do it correctly the first time.


-Brit

 

[Wire4Money]

Has the top end ever been done on this engine??? I recently bought a 98 GTXL with a blown engine and 160 hours. The piston had shattered, locking the crank. The mechanic rebuilding it said the 951 should have preventative top ends put in. The 951 hen it goes, really goes.

 

[fireball451]

If it just threw a rod and still had good compression prior to the rod toss...
I would suspect water, moisture, lack of fogging....etc... could had let the rod start to rust, weaken, then break.
From what i have read, that is a common problem as well with the 951.
For sure, rebuild and clean the entire fuel system.
Be sure to use genuine MIKUNI kits.
Go ahead and get the needle and seat and test the pop.
Clean all fittings, selector valve, etc......
Fuel and carb delivery could have let one cylinder start to seize and led to the eventual rod toss as well.
Unless you had an overheat alarm, I doubt that that would be an issue.
There are alot of mixed opinions on oil pump failures.
Lines get old and break or slip off fittings over time.
I guess the plastic drive could get brittle and break.
Things do age over time and can fail.
My choice was to go premix.
You will burn more oil, use more spark plugs, but its cheaper than a blown engine.
Premixing is VERY inconveniant too.

 

[custompartsguy]

Thanks for your input fireball, I agree that the source of the problems needs to be identified. You make some good points about SBT, it's always good to see some positive feedback. I'm going to continue to look at my options and hopefully make a decision by the end of the week... Anyone else have an SBT experience they would like to share (good or bad)?

Now to address the main problem...

1. Possible oil pump failure.
2. Fuel delivery/carb problem. (I still have the grey fuel lines... Yeah I know they will be replaced).
3. Cooling issue.
Is there anything else I should be looking at? keep in mind the 951 had a lot of hours on it however the compression was still good.

A few questions:

Are there any cons to removing the oil pump all together? I see a lot of you with two strokes have done it.

Also should I go ahead rebuild my carbs since I have everything torn out?

Will I need to remove the pump assembly in order to use the “shaft line up tool” when I put everything back together?

Sorry for all the questions but this is my first ski rebuild and I want to do it correctly the first time.


-Brit

there are pros and cons to removal of the oil pump, the factory oil injection system is great when it works because it gives you the exact oil you need when it is needed, premixing is great because you do not have to worry about a oil pump going bad however it provides the exact same amount of oil at all times, thus you will be replacing the spark plugs more often. as for the decision to do which one, that is your choice, I run premix in my 2000 gtx 951, note if you do decide to run premix then when you remove the oil pump you need to also remove the front engine cover and remove the oil pump drive shaft be sure to mix 40:1............since everything is torn down then yes at least clean the carbs and replace anything damaged, do not replace the needle/seat or any springs unless the factory ones are bad, I do not care what rebuild kit you buy retain the factory needle/seat and spring unless damaged.,..........engine/pump line up.....yes, you will need to remove the jet pump and drive shaft to use the alignment tool...................remove and clean your rave valves, when you remove them make sure to take note exactly how they came apart and make sure the go back together the exact same way and replace the bellows if damaged..........replace the front fuel canister filter and carb fuel filters as well.............while you have it apart inspect your wear ring and impeller for damage...............when you remove your driveshaft make sure the pto side of it has the rubber stopper on it and do not lose it, if it is not on there when you remove it then fish it out of the pto...........inspect your exhaust and make sure none of the plugs need to be replaced.....if they are corroded and leaking then have new ones tig welded in before you put back together.....you dont want to have problems down the road that could have been fixed before hand.

 

[custompartsguy]

Well our weekend of fun was interrupted when my 951 deiced to throw a rod (It had 300+ hours on it). So now I'm kinda torn as far as what I should do for a new motor. I have read a lot of bad things about the SBT engines... Even know it seems to be the easy way to get back on the water I don't want to end up in the same situation after 20 hours of use. I guess I'm looking for alternatives to SBT so do any of you know of a reputable engine builder? Or does anyone have a low hour 951 for sale? I'm also up for opinions good or bad about SBT.

On a side note my current block now has about a 2" hole in it, I know it can be welded but are there any cons to fixing a blown out block?

Fixing a hole in the block is like thowing away money, talk to any good engine rebuild performance shop and they will tell you the same thing, they will not fix it.

 

[3beers2many]

Thanks for the info guys! I'm sure I will have more questions as I go. For now I have a place to start, I'll keep you guys posted.

 

[tjcin]

I have used SBT 2 times now for engines. One for a Kawi 750 and one that I am working on right now, a 98 GTX. I don't have the GTX running yet so I can't tell if all will be good with the 951. The Kawi is 2 yrs and still running. If you plan on keeping the ski, spring for the 2yr warranty. Also, just out of curiousity was it the rear cylinder that threw the rod?

 

[3beers2many]

I have used SBT 2 times now for engines. One for a Kawi 750 and one that I am working on right now, a 98 GTX. I don't have the GTX running yet so I can't tell if all will be good with the 951. The Kawi is 2 yrs and still running. If you plan on keeping the ski, spring for the 2yr warranty. Also, just out of curiousity was it the rear cylinder that threw the rod?

Yeah, the two year warranty is tempting. It was the rear cylinder that threw the rod...