New SBT motor will not start. Yamaha MR1 HO

[Cmonst]

This is turning into a very frustrating situation. I purchased a new/rebuilt yamaha MR1 HO motor for an SX230HO from SBT and it will not start. The motor turns over, verified spark, fuel injectors are spraying, fuel pressure good and compression on all 4 cylinders, the only thing left is timing. Also verified through yds that all sensors are functional. It does not backfire which leads me to believe the motor has a problem with the timing. Other notes... the previous motor was replaced because it threw a bearing, this was verified by SBT when I turned in the core, also I did run the old motor before pulling it to get the oil warm and suck it out. Transfered all the accessory parts after cleaning and replacing all seals to make sure all the metal shaving from the old motor were gone this was not difficult, dropped the motor in and no start. Now after speaking to their tech support department and explaining the same as above they need me to repull the new motor and send it back to them my expense, that just got picked up March 25 and completed the install two weeks ago. I spent the last 2 weeks troubleshooting the motor and verifying it wasn't some other part of the system everything checks out. So my question is how can I verify if the timing is off without disassembling the block, I will of course be removing the accessories but after it's stripped down is there a way to verify if the timing without disassembling the core, suggestions are greatly appreciated!

 

[kbell413]

Do you have a service manual? This info is all in there and probably explained better and with photos than I can do for you. Here is how you would check though:

Bring cyclinder #1 up to top dead center and pull the valve cover off. There are punch marks on the cam sprockets that you need to look for. Those punch marks should be at 9 & 12 on the intake side, 12 & 3 on the exhaust side. Essentially one punch mark at 12 o'clock position and the other towards the outside of the motor even with the top of the head. If you find something different then your timing is off.

 

[zipper]

and

 

[Cmonst]

I do have the service manual but I cannot remove the valve cover per the sbt warranty. So I wanted to se if there was a way to verify the timing without removing it

 

[zipper]

Well that sucks! Are you sure all the interlocks (kill switches) are in good working order?

 

[kbell413]

I do have the service manual but I cannot remove the valve cover per the sbt warranty. So I wanted to se if there was a way to verify it was 180 degrees off because I do not have faith they will be honest about it if it is the case. Putting a motor together incorrectly might be a little embarrassing for them. Just my opinion though

No way to verify it without removing the valve cover that I have ever seen or can think of. Best of luck with SBT. I almost bought a short block from them 2 years ago but had read to many horror stories to pull the trigger. My 08 AR210 had a cracked water jacket that was leaking cooling water into my bilge. Figured I'd try welding it back together first which wound up working out okay. I had to change the head gasket after welding. I marked the cam chain and sprockets so it'd be easy to reassemble but while the head was off, the cam chain slipped off the lower sprocket. Made a lot more work for me having to retime it when reassembling. She's still running strong to this day for my buddy though!

 

[Cmonst]

I checked all the kill switches and verified it using YDS. The other motor in the boat starts right away. Both it and the older motor I pulled started almost right away even after sitting for 2 months.

 

[Cmonst]

I was thinking once the motor is out again I can see parts of the crank shaft and probably verify if it's close.

 

[jmargo]

Request permission to pull the valve cover with their tech support. It will get expensive to ship it back just for them to say it is all good. What is preventing the VC from coming off ? Tamper seal ?

 

[Cmonst]

That is not something they will even give permission to mechanic shops for... All the seals they install are marked with a tamper seal. The shipping is not the main issue for me it's the time that has to be invested in installing the motor twice. I wanted to verify it wasn't something wrong with the injectors or ignition... a problem that originated from the original parts SBT does not provide as part of the core motor all of these checked out visually and when tested using YDS. This time I'm trying to make the most of it and recording the whole process but it sucks to have to do it twice and miss good time on the water.

 

[jmargo]

You spray starter fluid down the intake yet ? I would exhaust all options before pulling it again.

 

[Cmonst]

Yes I sprayed starter fluid as one of the first test before pulling the throttle body to check the injectors. When I first tried to start the motor plugs were wet after it failed to start. But I went ahead and visually testing them after pulling the throttle body to be sure. Fuel pressure was also verified and in spec. Spark was visually verified and checked with an inline tester. Then I verified compression... I did not want to have to pull this motor again but now I don't see another option.

 

[Cmonst]

Well tearing into the motor again I found the woodruff key was sheered off and looks like it locked just a little behind where it should be. I'm thinking this caused the spark to be retarded enough to cause the engine to not fire correctly.

 

[Cmonst]

After installing new woodruff key and reinstalling the motor it fired right up! So happy thats all it was.

 

[kbell413]

After installing new woodruff key and reinstalling the motor it fired right up! So happy thats all it was.

Glad you got it sorted. Happy boating!

 

[Beachbummer]

Which version did you buy? New Sbt or rebuilt? Keep us posted, we don't have much first hand experience with SBT on the board for the MR1

 

[Cmonst]

I purchased the rebuilt SBT motor with the 2 year warranty and exchanged the core. I still have to go through the break in process so I will keep it updating how it goes . But after doing the removal and installation twice it was not too bad and took an afternoon each time. I took my time the first round disassembling the accessories and opening them all up to replace seals and clean corrosion. Overall everything was straight forward with the use of the manual.

 

[Beachbummer]

So why did you do it twice? One spun a bearing, and then other?

Thanks for sharing.

 

[itsdgm]

Wow, that’s frustrating. At least you’re back up and running again. So it sounds like you were able to diagnose and replace the woodruff key without sending it back and without breaking any tamper seals and voiding the warranty? If so, that’s a victory.

 

[84rzv500r]

Good catch.... I have 2 new SBT MR-1 HO engines in my LS2000/AR210 Re-power, one of them came with a defective half moon key that wouldn't let the flywheel seat properly.. I replaced it with a spare OEM key and it worked fine... no other issues.. they could have cleaned up the intake runner castings a bit as they are leaving some free HP on the table...