TRX250r.org

Author Topic: UPP Intake Boot Ripped  (Read 2814 times)

Online croat1

Re: UPP Intake Boot Ripped
« Reply #15 on: June 18, 2019, 09:03:24 PM »
Very informative thread, thank you for sharing that info with us Jerry!

X2 thanks Mr. Hall

Joe

Offline 2Nubs

Re: UPP Intake Boot Ripped
« Reply #16 on: June 19, 2019, 08:08:12 AM »
Excellent info, thank you.

I believe some of what I gathered from that bit is that the OEM works well if it is not dry or cracked?

I'm interested to see if my carb is properly suspended now. 

For anyone interested in how destructive harmonic resonance can be, Youtube search for "CH-47 Chinook Harmonic Resonance"
‘86 330

Offline hickwheeler

Re: UPP Intake Boot Ripped
« Reply #17 on: June 19, 2019, 01:17:34 PM »
Great info Mr. Hall. I think the info of that post should be made a sticky. Thanks for sharing your wisdom
88 hybrid 431 puma
88 (BOF Build) stock motor and oem 89 plastics
More in the works

Offline F-Red

Re: UPP Intake Boot Ripped
« Reply #18 on: June 19, 2019, 03:13:58 PM »
Leave it to Jerry to go the extra effort and BLOW our minds! Can we assume, Sonny's billet intake would be the answer?


Want To See My Wieners?

Offline Skeans1

Re: UPP Intake Boot Ripped
« Reply #19 on: June 20, 2019, 04:26:18 AM »
Leave it to Jerry to go the extra effort and BLOW our minds! Can we assume, Sonny's billet intake would be the answer?



This is from Jerry’s paragraph
I have seen enough burned up pistons to fill a few 55 gallon barrels because of improper vibration damping when using old hardened oem manifolds,  billet manifolds with the short 2-bolt rubber flanges and reed assemblies that incorporate the carb to reed adaptor as a one-piece casting with a short hose and 2 hose clamps.

Offline Tbone07

Re: UPP Intake Boot Ripped
« Reply #20 on: June 20, 2019, 03:24:54 PM »
Leave it to Jerry to go the extra effort and BLOW our minds! Can we assume, Sonny's billet intake would be the answer?




Well if we're to take Jerry's analysis, I'd say that intake would only make the problem worse. Unless that rubber connector he uses is soft enough to dampen the vibrations.

The UPP boot is still probably the best route to go. Just gotta figure out the correct mounting so it doesn't torque the intake, and rip like the OP's did.
LED Performance 350 Sphynx - XC Machine
Laeger's-Roll-GThunder-HLS-PEP-HiPer-GBC

RIP Laz

Offline Jerry Hall

Re: UPP Intake Boot Ripped
« Reply #21 on: June 21, 2019, 01:54:46 AM »
If you have any of the intake manifolds mentioned in my earlier post and are having detonation and or piston failures, I would run some test to determine if the manifold may be the cause. 

Running the upper vent hoses into a catch-can is another method of testing for vibration induced float bowl foaming. 

The vent line that comes out of the bottom of the float bowl on most carburetors should not be routed into the catch-can.  This vent hose is usually connected to a stand pipe that dumps fuel on the ground almost every time the brakes are applied. The fuel level in the front of the float bowl rises under hard braking.  The purpose of the stand pipe is to keep the fuel level below the pilot jet transition holes to prevent enriching the mixture or flooding the engine during braking.

The top of the catch can must be below the bottom of the float bowl.  The catch-can must be well vented.  The ends of all lines that dump into the catch-can must NEVER be allowed to be submerged in the fuel that may fill the catch can.  If the vent lines in the carburetor are pinched, partially restricted with fuel or partially filled with fuel, the float bowl chamber may not experience atmospheric pressure.  A carburetor that does not experience true atmospheric pressure at all times, can make the Air Fuel Mixture very unpredictable.

The billet manifolds in the pictures look like the style of manifolds I have had problems with.   I have also used manifolds that look like the ones in the picture and not had any problems.  I have used old hardened OEM type manifolds and Boysen type rad valves and not had problems.  Every bike has different vibration characteristics due to crankshafts that not true, loose main bearings or lose main bearing pockets, worn main bearing journals on the ends of the crank webs, improperly rebuilt counter balancers, pistons that are not the same weight as the OEM Honda piston, broken or missing cylinder head stays, loose motor mount bolts, cracked frames, after market frames (have a different resonance frequency than OEM frames), shock absorbers, tires, tire pressure....... the list goes on. 

Offline SFricia

Re: UPP Intake Boot Ripped
« Reply #22 on: August 02, 2019, 10:46:00 PM »
We all have to remember that we are dealing with a consumable part. Rubber doesn't last forever whether it is an OEM boot or a billet manifold.

I have been drag racing 2-strokes for over 20 years and I have had issues with both styles. Neither are without issue, but an issue with the UPP is the stress you put on the intake by trying to force it into an unnatural position to get it to fit inside the chassis.