Would you run this Di head?

[blairwill4]

As the title says. Would you bolt this back on? Doing Pistons rings and bore.

 

[racerxxx]

Nope, I wouldn't run that. Especially if it's a flip, you don't want the next guy coming back to you.

 

[blairwill4]

It's not a flip I'm doing it for someone. Can it be resurfaced do you think?

 

[ski-d00]

Yes, I would use it as long as it's flat and sealing surfaces are good which they normally are. All you need to do is knock off the high spots with a dremel and remove any pieces such as embedded ring pieces which doesn't even look like you have any. Do not remove material as this will lower compression so do not sand or smooth out. I've run heads much worse than that and they have always been fine and will last just as long as a new head with identical compression to the other side.

In a combustion chamber and air/fuel travel in general, you don't need smooth surfaces. In fact, rougher surfaces help to atomize air/fuel mixture better.

 

[AdamXP800]

That's pretty jacked up. As cheap as used heads are, I'd just find a used one.

 

[Chester]

Nope, you shouldn't not run that head. I have a good used one for $50 plus shipping.

Chester

 

[1of500]

In a combustion chamber and air/fuel travel in general, you don't need smooth surfaces. In fact, rougher surfaces help to atomize air/fuel mixture better.

I think you are referringto the intake tract.

 

[blairwill4]

Nope, you shouldn't not run that head. I have a good used one for $50 plus shipping.

Chester

Chester I'll take it. Your inbox is full so I can't pm you

 

[Sportster-2001-951C-Stock]

Assuming you have big stones, you could give it a "sidewalk shave" and slap it back on would probably be okay. That's not the right way to do it of course, and it's not gonna be yours so you probably want to avoid doing that for the little bit of money it'll cost to put something undamaged on there.

IMO

 

[blairwill4]

I'm trying to get this back together ASAP does anyone want to sell me a used head?

 

[racerxxx]

I'm trying to get this back together ASAP does anyone want to sell me a used head?

[MENTION=13190]Chester[/MENTION] wants to sell you one. I know you said his mail box is full so the @ sign in front of his name will get him here.

 

[blairwill4]

[MENTION=13190]Chester[/MENTION] I'll take it but your mail box is full on here.

 

[1of500]

Try him on pwc2day

 

[blairwill4]

Same name over there?

 

[1of500]

Yes sir it is

 

[blairwill4]

Perfect I found him and shot him a pm. Thanks for the help guys. Our of curiosity for those that said don't run it can i ask why?

 

[racerxxx]

I wouldn't run it just in case there is a fragment you can't see that becomes dislodged and fall back into the cylinder. The other reason, I'd be afraid that you'd get a hot spot and cause detonation (long shot). For me the reward is not worth the risk.

 

[blairwill4]

So something that's confusing me.... Is it possible for a Di to run lean? The original diagnosis from the guy was cracked oil line somewhere, oil was leaking out, compression dropped to about 60 psi per cylinder. Well when I got it all apart I found no cracks and no leaks and the bottom end looks like it has plenty of lube which is where the oil inlets are on the ski. Plugs were black not grey or white. The ski does have 325 hours on it.....

 

[Chester]

Sorry for the delay. I'll dig up that head this week.

Chester

 

[68ragtop]

So something that's confusing me.... Is it possible for a Di to run lean? The original diagnosis from the guy was cracked oil line somewhere, oil was leaking out, compression dropped to about 60 psi per cylinder. Well when I got it all apart I found no cracks and no leaks and the bottom end looks like it has plenty of lube which is where the oil inlets are on the ski. Plugs were black not grey or white. The ski does have 325 hours on it.....

Sure can, but the lean condition would normally be from other components not being up to snuff. Most likely the fuel system having a restriction, or drop in fuel pressure under high demand. The electronics monitor everything the engine is doing except the air & fuel pressures. So, if you have a fuel problem, exhaust leak, or case leak, this could cause a meltdown. Plugs are a little hard to read on a DI unless you do a wide open throttle chop on the water, darker or wet looking plugs are common any other time because of how the fuel is injected right next to the plugs. Piston wash can be read, but because its oil & air only through the ports, its a little different looking.

The DI is complicated & gets a bad wrap because of how hard they can be to diagnose. If BRP could have incorporated a fuel & air pressure monitor into the rails there would have been very few engine failures IMO. I DI should run as smooth as a sewing machine, if their operators ride them when they have symptoms of a problem, there is a good chance of engine catastrophe.

 

[blairwill4]

I'm going to pull the fuel pump and make sure the screens are cleaned. Of course the motor went, when a friend , of a friend, that was someone's cousin, twice removed was riding it. So the symptoms leading up to it are not certain.

 

[68ragtop]

Thats usually when they die, suck in a rope, or end up upside down.....
Maybe all three?

I have found a healthy & clean fuel & air system will make the required 107 fuel pressure very quickly when cranking/starting. On the water, they will rise past 107 at higher RPM's because of the increased rate of the Air pump. If the fuel pressure drops lower, rather than go higher under demand there is a problem even if its not that symptomatic. Both the fuel & air pump are capable of making a LOT more pressure than what their regulators keep them at. But as soon as those pressures get below the regulated pressure, problems are coming.

 

[ski-d00]

The majority of DI rebuilds I do are from using the wrong oil and the failure will burn each cylinder down so when I see sudden low psi in both cylinders that's my first thought. A friend will borrow it and put the wrong oil in it and boom. The DI is the most sensitive to wrong oil since it relies on it more than any other seadoo motor for lubrication and cooling. The DI also uses the least fuel per hp than any other motor but certainly is oil rich as a necessity.

325 hours(and 15 years) is a lot for a stock DI motor and it is due for a rebuild. You should test the oil pump when tore down but they typically are very reliable. Low fuel pressure is not normally a reason for engine failure, typically it won't run or barely runs with a bad fuel pump. Changing the two filters in the bottom of the fuel pump is always a good idea but doesn't normally cause running problems.

Regarding your DI head, they made two styles so make sure you get the right one and they are not interchangeable unless you swap other fuel rail parts such as air injectors.

I have a lot of DI parts as well as BUDS(which does help in DI issues) and can help since I'm only an hour away from you. I grew up in Ft. Wayne and get there every couple weeks.

 

[blairwill4]

That would be awesome. I still haven't gotten a replacement head for it. The guy has Seadoo oil in the storage bucket but the oil in the tank is almost purple??

 

[ski-d00]

If it's purple, it's not seadoo oil which is red(newer) or brown(older xps synthetic). I only use seadoo oil but I know others use quicksilver and amsoil full synthetic api approved oil. There is a royal purple full synthetic 2 stroke oil which I don't know nothing about but I do know there are plenty of purplish colored tcw3 oils that are purple or green colored which spells death to a DI.

$50 for a nice used DI head is a great price and they normally sell for around $100 especially if they are a gen 1 585 which is what you need.