Fini-Biscout MK200-1.5M has insufficient air to operate air tools

Published Categorized as Fini 4 Comments on Fini-Biscout MK200-1.5M has insufficient air to operate air tools

Hey! This site is reader-supported and we earn commissions if you purchase products from retailers after clicking on a link from our site.

by John
(Steinbach, Manitoba, Canada)

It is a Fini-Biscout MK200-1.5M dual tank compressor runs on 120V which I purchased new about 20 years ago. Compressor has been used very very little but it had always worked well even running framing nailers.

It builds up to normal operating pressure as it always did and shuts off at correct pressure.

However when using it unloads air at normal pressure but quickly pressure drops to where the tools don’t work.

If you continue to hold tool trigger switch, slowly it starts discharging air again until it hits normal operating pressure but does not last very long and then drops off till pump kicks in to build up pressure again.

It just repeats this cycle.

Haven’t done anything to diagnose yet and I’m not very knowledgeable about trouble shooting this.

To me it looks like it is unloading one tank at a time with perhaps a blockage between the tanks preventing a continuous discharge of air?


Fini-Biscout MK200-1.5M
by: Bill

Be nice to see a photo or two of your compressor!

When I started reading your post I thought that here was another undersized air compressor.

Yet if it has worked well in the past, something has changed on your Fini-Biscout MK200-1.5M John, as you have noted.

Possible blockage between tanks? Maybe, but unlikely.

I’d tend to look to the regulator malfunctioning.

Maybe try pulling air after you’ve removed the regulator?


Some more info on my Fini Biscout
by: John

Did some checks this afternoon relating to regulator comment.

I found that the 2 gauges don’t make sense.

Max tank pressure was 142 PSI @ cutoff and line pressure was 162 @ cutoff.

As I mentioned initially line pressure would bleed down with tool usage to almost nothing still showing about 135 PSI line then slowly come back up to tank pressure but watching line pres. @ regulator I heard the sound of diaphragm letting go and a thump and then line press. quickly jumped, drained down with tool usage and compressor restarted.

Could the diaphragm be sticking in the switch and can it be cleaned and re-lubed?


Fini-Biscout issues
by: John

Well it looks like the one suggested probable fault was spot on. Replaced the regulator and now it functions properly again although it seems to take longer now to bring the compressor up to max pressure. I can live with that. Thanks. for your help.


by: Bill

Glad to hear it John, and you are certainly welcome.

Slower than normal build pressure points to, among other things, pump valves, pump gaskets, piston seals. Good luck.

New comment? New question? Please add it here along with photos to help others help you with your compressor and equipment problem!

By Aidan Weeks

A passionate Mechanical Engineer with endless enthusiasm for fluid power - building off the back of over 18 years of high quality contribution and discussion stimulated by Bill Wade here at About Air Compressors. With both practical and theoretical experience in pneumatics and hydraulics, I'm putting my knowledge to work - and working my grey-matter through my research, assistance and publishing work here at About Air Compressors. Feel free to reach out any time! P.S. A HUGE shout out to Doug who really offers such great value to all visitors to About Air Compressors - once again, feeling like I'm standing on the shoulders of GIANTS by getting to work alongside such a great community

Notify of
Inline Feedbacks
View all comments

does anyone know where to buy a gasket set for the MK200-1.5M . mine won’t pressure up over 60 psi. Removed head and gaskets are no good. thanks for any help

I don’t see any, but then you didn’t give a fini model number (e.g. F3OL197N )
If just search fini parts, you’ll get a few places that sell parts and you can look through what they have.
Failing that you can try making your own. If it’s flat, auto head gasket sheet and a sharp knife…

Good luck.

I also have a Fini-Biscout compressor, dual tank, 120V, which I also purchased new, 20+ years ago, which I use rarely. I changed the oil a few years ago. I pull up the start switch and away we go! Today, pulled up the start switch, it started then quit (2 seconds). It was on a long extension cord, but never a problem before. I let it rest and plugged it direct to a wall plug after an hour – still nothing? I was looking for a reset button…

Can it be fixed? Is it worth fixing? Thanks, Kevin, Toronto.

“Can it be fixed?” Yes
“Is it worth fixing?” That’s up to you.
Got a model number?
Did you notice if it got hot? Sitting unused, and given it initially started, I’d guess a bad run capacitor. I don’t suppose you have the manual for it?
And yes, there’s probably a reset switch/button, somewhere…
You might want to verify you have still have power at the outlet, and that it’s getting all the way to the switch. Power cords can wear out.

Last edited 2 years ago by Doug in