Thanks for the advice. I have a SS waste tank. My runs are either 100 or 150, but I sometimes go to 200. The suction is noticeably less with each 50 foot section. Considering using a kunkle to preserve my lift out to longer runs.
You could check your vacuum and set (calibrate)
If you have a spare vacuum gauge or you could use a autometer vacuum gauge
run your machine full rpm
connect all your hoses and connect to your machine
block vacuum and measure and record your vacuum
it should be within specs
if not make adjustment at vac relief valve
you might want to replace the traditional/standard ring worm stainless steel hose clamps. those will weaken and cause vacuum leaks
I replaced mine with stainless "T" bolt hose clamps found at a marine shop.
"T" bolt hose clamps are far superior that the ring worm traditional type
but "T" bolt hose clamps arent cheap expect to pay between $5.50-7.50 each and be careful not to over tighten them, they have superior clamping power and could warp or crush a port/pipe.
if you are not sure why you have so low vacuum then I suggest doing a vacuum leak test. Smoke test are superior in my opinion.
youll need to inject constant smoke into a vacuum port and look for smoke leaks
if a seal or gasket is leaking, youll see it.
I dont run 4 to the door. I do not believe in it unless im running 350 ft +
if you are mostly running 0-150 constantly then why all of the work, weight, and expense on large hoses, and Fuel ( for us hear its at $6.30 a gal regular) why waste money and time. Setup is a pain whenever dealing with 4 inch hoses, even if its at the first 50 (technically 100 ft ) and then a WYE reducer adaptor. TO me it makes no sense if you do not over saturate the carpet and do thorough dry passes.
I dont have issues with drying and im fine without the 4 to the door. usually the max drying time is 24hrs.