• This site contains eBay affiliate links for which Sea-Doo Forum may be compensated.

96 XP Heavy Smoke at Start-up

Status
Not open for further replies.

jcsign

New Member
I purchased a 1996 XP last summer and noticed that whenever it is first started after sitting when the engine is cool, the exhaust billows out excessive smoke (oil burning). I mean excessive. My neighbors suggest I use it to fog the lake for mosquitos.

I push the choke in shortly after it starts up so I know it is not a rich mixture. It seems like it is pumping in an excessive abount of oil at the start. After I run it in a short circle to warm it up (1 minute or so) the smoke diminishes and the exhaust is normal.

Any ideas on what could be causing this? Is it normal for this engine? (Rotax 787 engine/ 780cc)

Thanks for any suggestions.
Jeff
 
rv seal..

possible, that your rv seal is leak'n. When that happens, it'll leak, and build up in the journal assy, where the gas/oil mixes in, prior to transport to top end. If bad, many people on the forum suggest, this is syptoms of more things to come, so better off rebuilding the whole motor/goin to sbt. I say, if compression good, and think you have some "miles" left on motor, then just replace the seal...
 
RV Seal?

Thanks for the reply timmyboy76. What is the RV seal? Sorry I am not up on the jetski lingo. Is this part of the oil injection pump assembly? Also, what is "goin to sbt"?
 
sbt is a remanufactured engine house for pwc engines. They got the best price along with no-fault warranty.

For the RV=rotary valve, theres a "seal" there, which holds back the oil, theat comes in via the oil lines, if the seal is bad/get'n bad, it'll leak around it, and "flood" the rv plate, which then , poors into the "port holes" of the intake where the gas/oil is injected into..

Take gander at picture, the gear in middle of the 2-port holes, is the RV assy, which theres a seal there..
http://www.seadooforum.com/attachment.php?attachmentid=376&d=1212070399
 
Last edited by a moderator:
Thanks Timmyboy76

I got it now. It makes sense. It looks like quite a teardown to get to the rotary shaft seal. Like always, it is never a 'simple' task with anything I need to fix on this thing. Also, thanks for the lead on SBT. I also have a '95 XP with a blown engine (trashed rod bearing at crank). Wow, I looked at the prices and maybe I'll just sell that one for parts.

Thanks for taking the time to send me a picture of the 787.

Jeff
 
It may also be your crank seals and not the rotary valve seal. The only way to really know for sure is to remove the intake manifold and check it out. As for R/R of the rotary valve shaft and its seal....it "can" be done without tearing the motor down but if the splines are damaged then it'd need to be torn down and cleaned.

Also please note that SBT remanned engines will net you lower HP/torque than what you originally had. The way they cut the squish band and increase the dome volume does nothing to increase the performance of any motor. And the lack of attention to detail you will see in a lot of their motors will surprise you. Care to see pictures? I've got plenty for you to see before you make that plunge.
 
PWCdoc

PWCdoc,

Thank you for your reply. I was looking in my service manual and see that the rotary shaft seal is pressed into the block. IF it was bad, it looks like the engine has to come out because the lower unit needs to me removed in order to remove the rotary shaft.

To inspect if the rotary shaft is the problem (verses crank seals) after I pull the carbs off the intake manifold, what am I looking for? If the rotary valve seal is bad will there bee excessive oil inside the intake manifold? If so, is there any way that oil can bleed via gravity through the oil feed tubes attached at the intake ports? Any thoughts???

Thanks again,
Jeff
 
Try turning the fuel tap off between rides.
It might be as simple as needle and seats leaking and it will was oil from your pipe.
Does it leave a black stain on the ground?
Also the fittings on the manifold can stick and leak oil
Just a couple of ideas
 
It may also be your crank seals and not the rotary valve seal. The only way to really know for sure is to remove the intake manifold and check it out. As for R/R of the rotary valve shaft and its seal....it "can" be done without tearing the motor down but if the splines are damaged then it'd need to be torn down and cleaned.

Also please note that SBT remanned engines will net you lower HP/torque than what you originally had. The way they cut the squish band and increase the dome volume does nothing to increase the performance of any motor. And the lack of attention to detail you will see in a lot of their motors will surprise you. Care to see pictures? I've got plenty for you to see before you make that plunge.

Somewhat harsh, on SBT, yeah....I'm no mechanic, but from the few forums that are out there, there is however, some of the most respected/highly looked upon mechanics, that refer there site/motors....but hey, everyone has there opinion.:cheers:
 
On SBT.. if you plan on keeping the engine stock and riding like a normal PWC fan.. then SBT is a great deal and their engines will work fantastically. However, if your planning on modding your engine for racing or just hard core riding, I would not recommend SBT. They are in the business of making a relatively inexpensive "new" short block for those who need a freshening up. However, their cranks are not near as strong as an OEM or racing aftermarket crank. Also, your going to need (if your smart) special porting on a mod engine. That being said, if you keep your skis stock, go SBT. If you plan on modding, PM me. I'll get you in touch with some of the best racing engine builders there is.
 
Sold the 1995 with blown engine

Thanks for your inputs in SBT but I no longer need to go that direction. I sold the 1995XP yesterday that had the blown engine and bought a second 1996XP. I figured it was the most cost effective solution.

Regarding my original 1996XP, I still need to check into what is making it smoke so heavily when I first start it up after it has been sitting. The rotary seal may be my problem.

12nvy...it smokes even if I turn off the fuel switch when it is sitting between rides. However, when I start it up out of the water, it does leave an oil spot on the ground under the exhaust pipe. Obviously too much oil in the exhaust. I did not understand your point of "Also the fittings on the manifold can stick and leak oil". How do fittings stick? Which fittings do you mean?

Thanks again guys for your inputs.

Jeff
 
It sounds like your crank seal is starting to go. pull the spark plugs after about 30 seconds when you fire it up (when it smokes a lot).. compare the two. Let us know what you find and remember which spark plug is which. PTO or MAG.

Try to take a picture if you can.
 
PWCdoc,

Thank you for your reply. I was looking in my service manual and see that the rotary shaft seal is pressed into the block. IF it was bad, it looks like the engine has to come out because the lower unit needs to me removed in order to remove the rotary shaft.

snip

Thanks again,
Jeff

Jeff, if you are very careful then you can indeed install the shaft with the lower end assembled. I've done it numerous times.
 
Somewhat harsh, on SBT, yeah....I'm no mechanic, but from the few forums that are out there, there is however, some of the most respected/highly looked upon mechanics, that refer there site/motors....but hey, everyone has there opinion.:cheers:

Somewhat harsh? I don't think so. Epecially when it is truthful. A lot of mechanics will use the SBT motor because it is less work for them and net a quicker/higher return for their time. I myself rebuild all of the motors here myself and yes, I give a full warranty on what I do. I won't give a no fault warranty because, in my opinion, it's their marketing gimmick that attracts a quick buyer that doesn't research the product he will be getting sufficiently. If you care to take the time to really look at the end product and the potential ramifications down the road, it makes perfect sense to do it right with the right parts and not lose any performance.
 
PWCdoc,

To inspect if the rotary shaft is the problem (verses crank seals) after I pull the carbs off the intake manifold, what am I looking for? If the rotary valve seal is bad will there bee excessive oil inside the intake manifold? If so, is there any way that oil can bleed via gravity through the oil feed tubes attached at the intake ports? Any thoughts???

Thanks again,
Jeff

Jeff, what you need to do is remove the intake manifold and rotary valve. If you see oil in the recess where the rv seal is in the center then it may just be that seal. However, clean all of the oil out as best you can and allow it to sit for a few days and check it from time to time. If you see oil pooling up in the seal area again then chances are that is the culprit. But, if it does not pool back up then it is your crank seals that are leaking and you are looking at a rebuild on the crank. And if that is the case then you need to go ahead and mic the pistons/bores and see what your clearances are and consider going ahead with a full rebuild.

Also bear in mind that both the rv seal "and" crank seal/s could both be leaking at the same time.

If you get your front piston to TDC you can mark the cases, before you actually remove it, where the rv will go back in. You'll just need to make sure the front piston is back at TDC again. But, if it doesn't work out that way then we can help you to get it timed properly.
 
Somewhat harsh? I don't think so. Epecially when it is truthful. A lot of mechanics will use the SBT motor because it is less work for them and net a quicker/higher return for their time. I myself rebuild all of the motors here myself and yes, I give a full warranty on what I do. I won't give a no fault warranty because, in my opinion, it's their marketing gimmick that attracts a quick buyer that doesn't research the product he will be getting sufficiently. If you care to take the time to really look at the end product and the potential ramifications down the road, it makes perfect sense to do it right with the right parts and not lose any performance.

I hear ya, not that i agree w/ ur analogy 100%, but, I hear ya...:cheers:
 
Somewhat harsh? I don't think so. Epecially when it is truthful. A lot of mechanics will use the SBT motor because it is less work for them and net a quicker/higher return for their time. I myself rebuild all of the motors here myself and yes, I give a full warranty on what I do. I won't give a no fault warranty because, in my opinion, it's their marketing gimmick that attracts a quick buyer that doesn't research the product he will be getting sufficiently. If you care to take the time to really look at the end product and the potential ramifications down the road, it makes perfect sense to do it right with the right parts and not lose any performance.

I agree. Other than Pro-X pistons in some instances, I only use OEM parts on my customers engines. I've been a full time PWC Technician for 15 years now. I had my own shop (The Jet Factory of Canada) for 11 years, I worked for a Sea-Doo dealer for a year, and for the last 3 years I've been working as a mobile PWC tech. In 15 years, against my recommendations, I have installed 4 SBT engines only when the customer absolutely insisted on it. I make them deal with getting the engine from SBT and sending the old one back. I also make it very clear that if the SBT engine blows, they pay me again to do the work over. In one example, a couple of years ago, I replaced 2 engines in a Speedster with SBT engines. After 20 minutes, one engine failed. I diagnosed it and found the rotary valve not turning. The brass gear stripped. I imagine that a bent rotary shaft was used in the SBT rebuild.
I got paid twice for that job and the customers Speedster was down for over 3 weeks in the Summer.

Chester
 
I agree. Other than Pro-X pistons in some instances, I only use OEM parts on my customers engines. I've been a full time PWC Technician for 15 years now. I had my own shop (The Jet Factory of Canada) for 11 years, I worked for a Sea-Doo dealer for a year, and for the last 3 years I've been working as a mobile PWC tech. In 15 years, against my recommendations, I have installed 4 SBT engines only when the customer absolutely insisted on it. I make them deal with getting the engine from SBT and sending the old one back. I also make it very clear that if the SBT engine blows, they pay me again to do the work over. In one example, a couple of years ago, I replaced 2 engines in a Speedster with SBT engines. After 20 minutes, one engine failed. I diagnosed it and found the rotary valve not turning. The brass gear stripped. I imagine that a bent rotary shaft was used in the SBT rebuild.
I got paid twice for that job and the customers Speedster was down for over 3 weeks in the Summer.

Chester

I agree on the Pro-X pistons. I use them exclusively. Same foundry as some of the OEMs (Japanese) and same quality from my experience.
 
I agree on the Pro-X pistons. I use them exclusively. Same foundry as some of the OEMs (Japanese) and same quality from my experience.

Yup. ART in Japan makes the Pro-X pistons and the OEM's for Kawasaki and Yamaha.

Chester
 
I think we are getting off the subject!!!!!!!!!!!!
I meant the fittings where the oil sprays into your engine. They are a ball valve with a spring and can stick.
That can allow oil to siphon into the motor while sitting.
Crank seals (inner) could be leaking but they normally drain pretty quick and the motor wont turn over with the plugs in. (hyro lock)
Good luck. hard to say without seeing.
What colour are your plugs?
 
Status
Not open for further replies.
Back
Top