Yamaha suv shuts down ??

Wife's yamaha 1200 suv (1999) shuts down and needs to be restarted. This started yesterday and was very unexpected. She had to walk it back to the dock in 3-4 ft deep water because the battery was low and it would not crank over. After charging battery overnight, it fired right up and ran about a mile before it quit. This time it had enough battery to restart at least six times on the way back. Fuel is at 3/4 full and the oil is half full. Spark plugs are old but worked fine up until yesterday.

This is a two cycle engine with three cylinders and three carbs. I believe it is rated at 135 hp.

Any thoughts on how to find the problem ?? Bad gas ?? Carb dirty ??

Help !

erie_guy
Port Clinton, OH

Re: Yamaha suv shuts down ??

Hey erie_guy, look at this post Yamaha runs like a banshee then dies - "now it happens to me"

I had the exact same problem, and if not the exact same - very close. I plan on testing out what I had found mentioned in that post about a vent problem this weekend. I'll post another thread here when I find out if I was right or not on the problem

Re: Yamaha suv shuts down ??

Frozenokie,

Thanks for the link. The problems sound very similar. I checked the compression on the engine this morning and found:

#1 - dry 85 psi, wet 120 psi
#2 - dry 80 psi, wet 100 psi
#3 - dry 75 psi, wet 95 psi

They sound low to me, but I do not know what is acceptable. The engine starts dry without problem and in the water idles roughly. It seems to have quick getup, but then stalls while running at speed.

Sounds like a fuel issue to me. I am wondering if running with the gas cap loose will prove tank venting is not correct?

Perhaps I need a new fuel filter - or a separation filter to remove any water from the fuel.

Thanks for you advice. I hope we both resolve our problems.

erie_guy
Port Clinton, OH

Re: Yamaha suv shuts down ??

Me too. Don't like trailer ornaments Yeah, fuel or electrical is what comes to mind, but the air vent is so critical on these about like any engine. It was the long exagerated "hiss" when taking off the gas cap that told me I had a vent problem somewhere. I think they all give just a little "hiss" which is normal.

I do know that the compression is supposed to be around 120 or higher for my 97 GP760. However, when consulting with Jazz Motorsports (in your state) about purchasing the top end kit, the rep mentioned that I should have around 140-150 PSI in the GP1200. Yours probably close if not same. You might call them and talk to them - they seem very knowledgable on the subject.

I think I'll do a comp check on mine too just to see if there is something going on there. I hope not - I'm getting ready to do a top end on the 97 GP1200 next week, so don't want to do two at the same time but still curious

I will let ya know how this 760 does after the holiday weekend. Plan to be out tomorrow or Monday. I'll know very shortly after launching.

If you find the problem with yours, let us all know - we all can gather experience together.

Re: Yamaha suv shuts down ??

Well, didn't even make it to the lake. I noticed my compression is now 10 PSI on #1 and 135 on #2 ???????????????

I then pulled the oil pump to see if it was still working and NOT! The drive pin or shaft was sheared totally in half :facepalm: WTF - I just replaced that pump. I obviously am doing a top end on this ski too. Oh well, the joy of having toys.

As for you erie_guy, I know now why it was acting the way it was. When you lose compression, you lose fuel delivery because the fuel is pumped by the compression pulses coming from the cylinders. If you have no or low compression, it won't pump fuel. Even in the condition mine is in, I could pour a little gas/oil into the carbs and it would start.

So there ya go. Hope this helps you with yours and hope you have better findings than me

Re: Yamaha suv shuts down ??

Frozenokie,

Found the problem at last!!! The wife's Jet ski is a 1999 model SUV with the 1200 cc three cylinder engine. The oil lines from the pump to the carbs have slipped off the pump oil outlet nipples. Both #2 and #3 hoses to the carbs were disconnected. The pump was injecting the oil into the bilge not the carbs. This probably is the reason for the lower compression on these two cylinders and why the engine would not stay running for very long.

I am sure those two cylinders are scuffed and scored but I will try to lubricate and get the engine functioning for the admiral. She likes the new FX HO Cruiser, but at $13,000. she will have to make the old SUV last a few more years.

Depending on how the engine revives itself - with the oil lines reconnected will determine if I need to pull the heads and hone the cylinders. A rebuild kit is only a couple hundred and would be a good winter project.

If you have an oil injected engine, make sure the oil lines are still attached to the oil pump. The little tie-wraps they use instead of clamps are a joke. Proper metal clamps would have saved the engine from all this problem.

erie_guy
Port Clinton, OH

Re: Yamaha suv shuts down ??

Yep, I bought the style of clamps that you use the special crimping tool with (i forget the name of clamp). But I've heard that before with the oil lines slipping off. My guess is that the compression won't be enough for you to be happy. Probably did enough damage without getting oil that the scores and scuffs rob too much pressure.

Glad you found your problem though.

Re: Yamaha suv shuts down ??

Hi Okie,

I just finished replacing all the oil injection lines. The old ones were hard because of age and the hoses easily slipped off the pump nipples. The new tubing is softer and was clamped on to the nipples (allowing a couple inches of extra length to keep them from pulling off)

Do you have any experience on how to get the oil injection pump to fill these new oil lines before starting the engine. I hate to run the cylinders dry (no lube) while the oil injection pump slowly fills the new lines.

erie_guy
Port Clinton, OH

Thanks for a Beautiful day on Lake Erie. Today we fished perch and white bass.

Re: Yamaha suv shuts down ??

Cool! Glad to hear it. On the oil pump - I use an old style oil can that you fill up with oil and it allows you to slip it in the end of the tube and "force feed it" oil until it comes out the other end. I also did this without the check valves installed - they were the second thing installed.

First - loosen the little bleed screw on top of the oil pump and make sure oil comes out. Then fill a tube, pinch one end, connect the other end to the oil pump. Do the other line same way.

Then connect the check valves.

Then the other two lines (to the carb) fill with oil and connect to air intake.

I did my 760 last weekend finally and it did great. Put about 4 hours on double oil and the oiler woked well. I did have to bleed the oil pump again after I was on the water to remove remaining air from the pump - so be aware!!!

Have a good ride

Re: Yamaha suv shuts down ??

erie_guy said:

Depending on how the engine revives itself - with the oil lines reconnected will determine if I need to pull the heads and hone the cylinders. A rebuild kit is only a couple hundred and would be a good winter project.

erie_guy
Port Clinton, OH

Click to expand...

Have you finished this task? Be sure to run double oil to break it in again or it might not last long!

Since I'm done with the 760 my attention now goes to the 1200. I have the cylinder getting another sleeve and bored as we speak. Maybe next weekend for a break-in run on it