2008 Massimo 700 high speed problem

Robert G1 · July 22, 2022

Hi all. I'm new to the site. A few years ago I bought a used Massimo. Recently I've had a issue driving above 25mph. The engine won't go any faster. In fact it seems to sputter and hesitate. The whole engine shakes. I've changed air filter.oil,oil filter, throttle cable oil/air cooler,and carburetor and still no luck. I was wondering, could it be the fuel pump. Should I invest in an electric fuel pump? I'm just not sure. It starts fine and revs while in neutral. Any advice would be great. Thank you

KentC · July 23, 2022

I have the same problem with a Buck 400 since it was new. I rarely need any such speed, so I have ignored it. I would like any suggestions.

Greg Kilgore · July 23, 2022

Kinda acts like a Rev limiter or speed limiter.

Mine will not go above 10mph without the seat belt fastened. Check that or something along that line.

What is that red light in the gauge cluster?

Robert G1 · July 23, 2022

I thought and read about the seatbelt thing, I tried no luck. The red light is about two wheel/four wheel. I think it might be The fuel pump. I have something similar to this. I was thinking changing to a micro electric pump. Any advise would be greatly appreciated

Greg Kilgore · July 23, 2022

You could try a fuel pump as long as it would pump enough volume for what you need. And remember most electric fuel pumps like to push not pull. So the pump would need to be close to the tank. I replaced a fuel pump on a Kohler 18hp lawn mower with a cheap electric one and it has worked fine. But that was 1994 lawn mower not a side by side. Also if the pump supplys more gas than the machine uses there needs some place for extra gas to go so it doesn't flood the engine.

Look up the specs on what the max speed SHOULD be in LOW and HIGH vs what you actually get in LOW and HIGH. A sensor could think the machine is in low when actually in high and not letting it go any faster.

Is it the same speed on level ground vs an incline?

Really acts and sounds like a sensor or something limiting the speed. But I have been wrong before.

Someone more knowledgeable on the engines may be able to help.

Hope you get it fixed and post your fix

Joe Breaux · July 24, 2022

are you in 2 wheel drive?

Robert G1 · July 25, 2022

two. I think it could be the clutch. I was trying to get to the clutch belt, but the cover bolts would not loosen, they just kept spinning. any advise?

Greg Kilgore · July 26, 2022

Put a forked prybar or flat screw driver behind the bolt. Apply a little outward pressure as you loosen the bolt. Hopefully it's just the bolt and not the case.

After bolts are out. Maybe a thread chaser or maybe have to tap new threads a size bigger.

Robert G1 · July 26, 2022

That will be fun when I get to the bottom ones. They all seem to just spin. I will try. thanks

Greg Kilgore · July 26, 2022

Maybe take the door off and side skirt off that side to make things a little easier to get to.

Maybe a magnetic hex bit.

Use extensions. I had to use about 3 ft of extensions to get the case off my cfmoto. The cvt case was being the gas tank. Had to take off wheel to get the tank out of the way.

Just take your time. You'll get it. I have faith in your abilities.

Greg Kilgore · July 26, 2022

You said you bought it used.

Maybe the previous owner did some kinda bypass on the seat belt safety wire.

Check to see if there is any kind of wires going to the drivers side seat belt clip that tell the machine if you have uour seat belt on or not.

Possible if the previous owner did rig something, it might have came loose on one of your rides.

Just grasping at straws.

Robert G1 · August 2, 2022

Update, I'm in the midst of changing the clutch. I bought replacement parts. I noticed they included a one way bearing, but when I took off the old, there was no bearing. Do I put the new one on. I have an '08 Massimo 700. Technically, isssss it suppose to have one? Thank you

Greg Kilgore · August 2, 2022

One way bearing will slow down the machine when letting off the gas. To help hold back the machine when going down hills and such.

I don't know if itbis supposed to have the one way bearing or not. It can help save brake pads. Kinda of a personal preference.

You could go to alpha-sports or another site to see if their parts list shows a one-way bearing. Or in a repair manual to see what it says.

When the engine turns. The clutch grips the clutch drum and the bearing free spins basically. When you let off gas. The one way bearing kinda grabs and doesn't let the clutch drum spin freely. Causing it to grab forcing the engine to spin. The compression of the engine causes the machine to slow down. Not technical but this is how the bearing works. Sort of. The only way I know to explain it.

Again a personal preference. If you don't want the machine to hold itself back when letting off gas. Don't put it in. If you want the machine to hold back a little, install.

Either way, will not hurt top speed. Unless you install backwards.