Massimo T-Boss 750 hard starting

[Byron Johnson]

Does anyone have a had time starting there utv.

I have a T-Boss 750 and I have had to put 2 starters in and put heavier wire to the starter but it still has a problem starting. it will turn over and than die before it wil turn over again. could it be that there is to much compression that might cause this problem

 

Thank you

[Mbrew99]

I have a brand new one doing the same thing. Did you ever figure this out?

[RaceCraft]

This is a common issue. We are a dealer in Iowa and pretty much every new Tboss 750 (within the last year) have this issue. We are working on ECU programming to fix it.

[CDRK]

Brand new tboss 750. Won’t start. Not just hard to start. Won’t start. 

[CDRK]

Has the ECU programming fix been successful?

 

[RaceCraft]

Totally forgot about this post.... Yes, it has definitely helped!! 

[Jim from Hastings]

I have a  Massimo T-Boss 750 with this exact same problem.  They replaced my ECM...no change. I  basically burnt up my starter and positive wire to the starter. These were replaced once they found the root cause. The problem is the cam assembly.  It has a compression release at low (starting) RPMs. Centrifugal forces closes the valve at higher RPMs. Massimo was of little help to my dealer... three cams were tried.  Finally one worked.  It's like a new machine...this took  nine months. It's starts first time every time. How wonderful.  But it was a nightmare and more time in It's first nine

months in the shop than on the trail to get it fixed. Great side by side when you can start it.  Massimo needs to fix this cam issue, quit shipping machines to dealers that will not start and support the T-Boss 750.

Edited February 19, 2023 by Jim from Hastings

[Tom750]

On 2/18/2023 at 9:44 PM, Jim from Hastings said:

I have a  Massimo T-Boss 750 with this exact same problem.  They replaced my ECM...no change. I  basically burnt up my starter and positive wire to the starter. These were replaced once they found the root cause. The problem is the cam assembly.  It has a compression release at low (starting) RPMs. Centrifugal forces closes the valve at higher RPMs. Massimo was of little help to my dealer... three cams were tried.  Finally one worked.  It's like a new machine...this took  nine months. It's starts first time every time. How wonderful.  But it was a nightmare and more time in It's first nine

months in the shop than on the trail to get it fixed. Great side by side when you can start it.  Massimo needs to fix this cam issue, quit shipping machines to dealers that will not start and support the T-Boss 750.

 

Jim do you happen to know the part number for the cam that worked?

[Jim from Hastings]

I am quite sure they didn't change the part number and the change is so small it is hard to mic it to find if one is good or bad.  That problem is super annoying but once you get the cam that resets so it releases compression at next start IT WORKS GREAT. Please call PSI in Davison for more details.  Matt took lots of notes but I don't know if he still works there.  Let me know how it goes.  It is worth pursuing. 

[Brabe0524]

I've had my Tboss 750 for 2 years now and replaced the starter twice. It's not sitting on the side of the drive and once again having starter issues. Has anyone had any luck identifying a good one from a bad one? Jim I appreciate the insight and will try calling PSI, but since I'm in Iowa I'm not sure they'll be able to do much

Heck of a machine, but this starting issue has me livid....a known problem that Massimo isn't willing to address.

Did you have to replace the entire 72013 assembly or is it just one particular component?

Edited January 24, 2024 by Brabe0524
Added question

[Jim from Hastings]

Brabe0525,

They could only get the whole assembly,  as I recall. They had to try several to get a good one.  They gave me one of the bad ones that I look at every day. My Tboss had been like a new machine ever since.  It is almost impossible to start the T Boss with a defective cam as it won't allow any compression release when you try to start it. And yes,  you will burn out starters AMF starter wires.  It's great when it works right but at one time I was as frustrated as you sound. Stick with it until you get a good cam that will allow compression release. In going to try to include two pictures of the cam assembly.