MR1 low oil pressure

[cybuch]

Well, the SBT motor broke, took the boat out today to see if my water leak is solved and it sounds like I have a piston slapping. Call to SBT tomorrow. Goo news is water leak is solved, bad news is we are going to lake powell on wednesday. Guess I am pulling the motor out of my waverunner and putting it in my boat.

 

[Seadeals]

Dang! That sucks. On the plus side, you are really becoming an expert and knew something was up. On the bad side, you are really becoming an expert. Hope the swap goes smoothly!

 

[cybuch]

@Seadeals Thanks! I plan to get it all done tomorrow.

 

[cybuch]

Motor swap is done and she runs!

 

[cybuch]

@buckbuck Here is a picture of my oil pressure setup

 

[buckbuck]

You should create a time lapse video of your motor pulling. Sounds like you have a lot of experience.

 

[mark_m]

@buckbuck Here is a picture of my oil pressure setup

I'd like to see a writeup of this mod! Great setup... so clean!

 

[cybuch]

Got the motor back from SBT again (3rd motor), installed it and this time the oil is not aerating, the pressure is lower than I would like but it is stable. Fingers crossed it holds up. I still have till June for the warranty, so I plan on running the piss out of it till then.

 

[tdonoughue]

You go. Good luck! Run it like you stole it.

 

[cybuch]

Well, that didn't last. I finally gave up on SBT and bought a FXHO jetski (58 hours) to pull a good Yamaha brand motor from, installing it now. We are going to sell the boat, since we just bought a Baja boat. We no longer do the water sports and want to go fast!

 

[Bruce]

Well, that didn't last. I finally gave up on SBT and bought a FXHO jetski (58 hours) to pull a good Yamaha brand motor from, installing it now. We are going to sell the boat, since we just bought a Baja boat. We no longer do the water sports and want to go fast!

What about your flyboarding business?

 

[84rzv500r]

I have mechanical gauges on the MR-1's in my 2004 AR210 and I get 15-18 PSI cold at idle, 55-58 PSI hot WOT, 38-40PSI hot at 7000 cruise and 8-10 PSI hot at 1800 idle... Engines have almost 30 hours on them since new... I ran 10W-40 for the first 2 hours then dumped the oil and cut the filters and it was clean, then switched to 20-50 VR-1... I did install new MR-1 HO pumps on the new engines.. all seems fine.. I run the boat nearly everyday...

mech gauge installation

 

[cybuch]

What about your flyboarding business?

We haven't done much since the pandemic hit, going to sell it with the boat.

 

[cybuch]

I have mechanical gauges on the MR-1's in my 2004 AR210 and I get 15-18 PSI cold at idle, 55-58 PSI hot WOT, 38-40PSI hot at 7000 cruise and 8-10 PSI hot at 1800 idle... Engines have almost 30 hours on them since new... I ran 10W-40 for the first 2 hours then dumped the oil and cut the filters and it was clean, then switched to 20-50 VR-1... I did install new MR-1 HO pumps on the new engines.. all seems fine.. I run the boat nearly everyday...

mech gauge installation

I'm glad yours is working out for you. I just couldn't get a good motor from SBT.

 

[84rzv500r]

were they remans or "new" aftermarket... I looked high and low for good clean OEM motors and I just bit the bullet and crossed my fingers... i had good luck with SBT reman 1200's bout 300 hours is all the two strokes would do maybe a little better I were to baby them... If I have to do it again ill just bite the bulled and get two skis OEM 1.8 SVHO's pumps and all... I have also had good luck with and SBT 155 4-tec I bought the boat for price of the engine and it had 2 hours on it..

 

[cybuch]

were they remans or "new" aftermarket... I looked high and low for good clean OEM motors and I just bit the bullet and crossed my fingers... i had good luck with SBT reman 1200's bout 300 hours is all the two strokes would do maybe a little better I were to baby them... If I have to do it again ill just bite the bulled and get two skis OEM 1.8 SVHO's pumps and all... I have also had good luck with and SBT 155 4-tec I bought the boat for price of the engine and it had 2 hours on it..

It was a brand new SBT, not referb. If they were referb, I think it would have been much better. I don't think their self manufactured blocks are in spec. That's why I am just putting the wave runner motor in and calling it a day.

 

[wajetter]

, then switched to 20-50 VR-1... I did install new MR-1 HO pumps on the new engines.. all seems fine.. I run the boat nearly everyday...

mech gauge installation

Hi @84rzv500r
Just curious, why did you start using 20w-50 instead of 10w-40.
Also, did you consider full synthetic? 20-50 VR-1is conventional

 

[84rzv500r]

50 years of wrenchin and racin motorcycles (many 5 valve yamaha Genesis engines) AMA, AMA CCS, WERA, GP PRO, FUSA... cheap breakin 10W-40 dino oil with zinc, then 500 miles with VR1 (in the boat I think i ran 35 hours at the first change and then the final change is at 100hrs) then in the bikes i would switch to 15W-50 Mobil1 (given the climate) and in the Jet boat boat the plan is to switch to 25W-50 full synthetic at 100 hours... we would generally pick up 500 rpm on top in the bikes on the dyno and the track switching to full synthetic. Allowing the engine thermal cycles and the parts inside to get used to themselves before switching to full synthetic is the way I like to do it... I also don't like full synthetic for engines that don't get used regularly (ask mobil why they got out of the piston engine General Aviation synthetic oil business) IMHO PS the MR-1 only hodes about 5lbs of oil pressure at idle in 90+ degree ocean water with 10W-40, with 20W-50 thats more like 10lb at idle.. I ain't running no 71 series detroit here LOL (tho in some ways I wish I was running a pair of 6V-53TA's in my Jet boat)

 

[Brad_Ct]

Looks like I may experiencing the same issue with a remaned SBT engine. Installed it a few months ago and ran it for 3 hours with no issues and it’s been sitting since then. Started the boat up yesterday and got a low oil pressure light, shut it down and cleared the alarm then restarted it and no alarm.

 

[Nikokrzynowek]

So I’ve been in the process of rebuilding the 2 vx110 engines out of my ar210. Reading the service manual it says the main oil bearing clearances are .0002” - .0012” the crank mains measured around 1.3381”. Typical rule of thumb on bearing clearances is usually .0010” for every inch of journal diam. which should be around .0013”. Because I was skeptical about having such tight clearances, I called SBT and asked a tech what they do on their rebuild. They told me they go with the largest bearing size I think they told me green. He said the bearing clearance should only matter at an idle and when warmed up on RPM it wouldn’t matter. My guess is they don’t follow the service manual specs rebuilding these engines and putting larger bearings in the engines which creates lower oil pressure. Hopefully this weekend if we don’t get rained out I’ll be able to install both engines back in the boat and verify I have good oil pressure