TimMassimo

On 2/13/2021 at 1:55 PM, Joe Breaux said:

if its blowing out the reservoir, ITS A HEAD GASKET LEAK for sure .. these things are plagued with head gasket failures... try to use a YAMAHA gasket this time 

Thank you. I will look for the Yamaha gasket. I’m thinking of using Gasket Cinch in addition as well. 

14 hours ago, Joe Breaux said:

I dont have the part number.. My mechanic did the work..  but The HISUN 500 is a clone of the earlier Yamaha Rhino engine.. almost identical in every way.. he said Yamaha gasket was better quality ...its working great now.   Engine rebuilders say you can swap a Rhino engine into Massimo and it will all bolt up        

Thank you!

Hi Joe.  The coolant would make it to both sides of the motor although once I cranked it up the pressure was to much and forced the water out of the coolant reservoir.  We are assuming it’s a head gasket issue that will need to be replaced. 
 

Thank you for your trouble shooting assistance! 

4 hours ago, Joe Breaux said:

On mine it has a vent screw at  the pump and at the hose outlet on the head.. You must bleed out the air repeatedly from both as you add coolant with caps off .. if there is any air, the water will not flow .. you can drive it til the end of time and that air wont move by itself.  You have to get it out ...Overheating is a major issue with Massimo ... 

I just found the screw at the pump but my mechanic didn’t know there was one there, only the top screw. It must be air bound. Thank you!!

17 hours ago, kenfain said:

Looking at a water pump when it's in the hand is usually pretty easy to diagnose, because it'll turn roughly, with grinding, or be loose with sloppiness in the shaft. Lots of rust, leaking at the shaft, etc. Any one of these fairly obvious problems means a bad pump. 

Maybe just pulling the belt off and spin it freehand, and do a good visual check too. Or worst case, you have to pull it off to check it. If it's determined to be good, you're only out the price of gaskets. So I'd check it out before I just replaced it. 

I've heard of serpentine belts, that could be routed backwards over the water pump. Making the thing spin backwards. I'd consider that a severe longshot. 

Personally I'd suspect air in it, except for the fact that it was working good before. That seems a bit strange. But what's not uncommon is having to purge the air a couple times, or more on some vehicles. As you said, just keep topping it off for a few short drive cycles. See what happens. 

Thank you for the insight. I haven’t taken the cover off the water pump yet but now I’ll know what to look for. It is strange that it was fine for the first run of about an hour and now not so much.  Generally I don’t run it for more than 30 minutes or so since I’ve had it back. Thanks!!

I don’t believe there is a thermostat as the mechanic did not put one in- couldn’t find a match to fit. I will try to run it at idle and add coolant as it burps out and hope for the best.  The next step is to replace the water pump if that doesn’t work.

Thank you for help!

T-Boss 410, thank you for replying.  The radiator is cold at all times.  When I got it home it ran great and the coolant was cycling properly- then just stopped cycling randomly.  I was told the coolant system may need to “burp” although not sure how that works short of the normal bleeding process. Thanks again!

Hello. I have a 2017 Massimo 700-5. I have recently had the head gasket replaced with the head and base machines, all gaskets, valve seals, piston rings and a coolant flush. I drove it for about a total of two hours at different times and days and now the coolant is not reaching the head when it is running. I have tried to bleed it by jacking up the front end using the top screw in the water pump screw and get all the air out. After I run it for a few minutes the coolant get stuck in the radiator and it won’t circulate back to the head as it should.  Has anyone run into this? I’m not sure if there’s air in the system or the water pump does not work?