2019 Massimo MSU500 bangs when first starting out in L gear

[cwikscan]

When I start my Massimo MSU500 with cold engine and start off in L gear I hear a loud bang or snap and then it goes.  Doesn't do it once engine is warmed up.  Is idle too high or is  cold idle controlled by CPU?  I couldn't find any help on Youtube.  Maybe shift linkage?  I would greatly appreciate any input.  Thanks, I am new to the group and appreciate this forum.

Vince

 

[TapBoss]

So it backfires when first started?   And is this carb or injected?

[cwikscan]

No, it's a hard SNAP almost like it didn't quite get in gear and then loudly slaps into place and sometimes the UTV will jump ahead slightly even with my foot on the brake.

[cliffyk]

Could be shift linkage adjustment, or a problem with the shift drum/forks/cogs in the transmission. The idle speeed is controlled by the engine managemeny computer--it should be 1400-1500 rpm. What idle speed are you seeing?

How many miles/hours on the beast?

Does letting the engine warm just a bit (30-60 seconds) help? 

What grade of engine oil are you running (synthetic or conventional--the ttansmission is in the engine crankcase, lubricated by engine oil)?

When was it last changed?

Sorry for all the questions...

[cwikscan]

Thanks for the response.

It has 275 miles on it.

Yes, if engine warms up for a minute or so it shifts just fine.

Oil used is 10W40 conventional oil and it was changed within the last few days.

This morning I put transmission in neutral then loosened then tightened the shift rod  nuts as per maintenance manual.  I don't know if it helped or not because engine is warm.  I will try it again tomorrow AM and see if it made a difference.

[cliffyk]

Unfortunately due to the rather crude shifting mechanisms in these things (sliding cogged collars) stiff shifting when cold is normal--'cold" being not hot, not cold as in "Brrrr". My Hs400 does it going into reverse on each day's first ride regardless of how I adjust the linkage. You can try synthetic oil--it might help. I'm going to use 5W40 synthetic at my next change.

-cliff-

[cwikscan]

Good info Cliff.  Thanks.  I may try the synthetic route next oil change.

[Ridge Runner]

On the Coleman 550 outfitter, similar or same thing.  Easy fix.  Hold gear shift lever in low position until you start moving, then it’s fine.  Annoying, and shouldn’t be like that, but they are what they are.  Make sure you are using correct oil, I’m assuming 400 also has a wet clutch.  I could be wrong

[cliffyk]

The 400 does have a wet clutch, but a completely different 1-speed + reverse transmission.

[Ridge Runner]

Thank you

[cwikscan]

I did try holding in L until moving and that works.  After I adjusted the linkage it doesn't seem quite so bad.  Thanks for the input.

[Ridge Runner]

I’m glad it helped.   Any tips on shifter adjustment?

[cwikscan]

I had downloaded the service manual and followed it's procedure.  Simple and seemed to help but don't ask me how.  Place transmission in N then loosen the nuts on each end of the shift rod (right side is righty loosey.  Then retighten them.

[cliffyk]

5 hours ago, cwikscan said:

I had downloaded the service manual and followed it's procedure.  Simple and seemed to help but don't ask me how.  Place transmission in N then loosen the nuts on each end of the shift rod (right side is righty loosey.  Then retighten them.

Cool...

The shift drum in the tranny has detents and a spring-loaded ball that "snap" it into the selected gear--loosening and re-tightening  the linkage in neutral allows it to re-align itself with the drum's neutral position.

[Ridge Runner]

Thank you very much!  I’m going to try it.  

[cwikscan]

Great info, now I understand why that procedure works.  Thank you.

 

[Joe Breaux]

On 4/8/2021 at 1:44 PM, cwikscan said:

Good info Cliff.  Thanks.  I may try the synthetic route next oil change.

....be sure the oil you use is compatible with WET CLUTCHES .. I use Actevo 10W30 from Castrol for wet clutch applications in my MSU 500....                          from AMSOIL  ....." ......unfortunately, automotive motor oils for gasoline service; both synthetic and conventional, contain friction modifiers. Friction modifiers are additives that literally reduce friction and improve fuel economy. All automotive engine oils for gasoline service are now  mandated to contain these. Simply put, friction modifiers are incompatible with motorcycle wet clutches. They will cause the clutch to slip under load and eventually glaze the clutch plates until failure occurs . Once this occurs, the only cure is a replacement of the clutch plates"

[cwikscan]

Thank you.

[Massimo mom]

I have a massimo 500 we have replaced the wet and dry clutches . 
it works in low gear. Every once in a while it will leap to a stop.  It goes in low but when we try to put it in high it grinds and will not go.  Any advise on things to check before we replace the transmission.