84 250r pressure test

[averysdad]

Can anyone tell me What size pvc pipe I need to fit snugly in the intake boot? And what size freez plug do I need for the exhaust? I don't really want to take the carb and pipe of until I have the tester

[loganm]

Takes like 15 minutes to take them off dude.

Why are you doing a pressure test on an engine that you know has low compression? IMO top end refresh and crank seals (you don't need to split the cases for it if you're creative) and fresh gaskets before you do anything else.

[averysdad]

Well I am not a master mechanic/tuner like you. And also my bike has a silencer on it so may take me 20 or 30 min.

If it passes the pressure test I just need a top end if not I need a full rebuild top and bottom.

I don't think bad rings will effects the pressure test dose it?

[loganm]

Rings won't affect the pressure test. You don't necessarily need a full rebuild if it doesn't pass a pressure test. The only reason you would split the cases is to replace main bearings/crank rebuild, or replace bearings in the transmission.

You won't need to pull the silencer, just the header. If you still have an airbox it may take a little longer, I can pull the header and carb on mine in 5 but there isn't anything in the way. If the engine is still running with a worn out top end it is HIGHLY unlikely you need anything more than a top end refresh and seals. IMO I wouldn't even bother with a pressure test unless you're building a full blown race motor, and want to eliminate every variable possible.

[yaegerb]

Can anyone tell me What size pvc pipe I need to fit snugly in the intake boot? And what size freez plug do I need for the exhaust? I don't really want to take the carb and pipe of until I have the tester

Try 1-3/4" for the pvc pipe off the intake boot. 1-1/2 for the expandable exhaust plug. You can get the plug at autozone.

[averysdad]

Thanks yaegerb

[yaegerb]

Thanks yaegerb

No prob. You will also need a screw type clamp

[averysdad]

Got the carb and and pipe off yesterday to do the pressure test. A lot of oil was in the filter to carb boot looks like motor oil to me ? Or maybe it's mix oil? Looks like the slide is opening all the way even with my messed up thumb throttle lol.230118230120

[yaegerb]

likely mix oil. when you get a chance, check your float height.

[averysdad]

Started out a good day did the pressure test 6 lb for 6 min. Then after 1 hour it was at 5 lb. 15 min later it was at 2 lb sprayed the soap again and had a leak around my electrical tape. So I take it pressure test was good? 230260230261 I also changed the reeds they looked really good to me230262230263 now the problem is put everything back together and the bike will not start and gas is pouring out the overflow?? I didn't put the stock reed stops back on used the little plates that came with the new reeds is that right? Also do the reeds with the holes in them go on the block first then the solid one? I don't understand why it won't start and gas is pouring out the overflow? Was running fine before and I didn't take the carb apart.

[yaegerb]

Gas is running out of puke tube in bottom of carb or overflow on side of carb? Either way you either have junk stuck in your needle seat or your floats are sticking. Likely time to clean/rebuild carb, clean tank and put an inline fuel filter in. Great news on the pressure test!!! Yes putting on the little plates is correct. I assume you bought Boyesen power reeds and the holes go on first then the "flaps" cover the holes. You have it on correctly.

[averysdad]

Ya I was excited to tell you about the pressure test lol. I cleaned the carb last weekend I'll clean it again and the tank to this time. is there a way to set the float with a ruler? I don't want to wait 2 weeks for a float gage the way I do it is blow in the fuel line and level the float is that a good way to do it? I would like to check it with a clear line from the drain on the bottom like a water level but I don't see any screw to open the drain line only the big bolt in the bottom.

[yaegerb]

To properly set float height all you need are one of these
http://m.harborfreight.com/6-in-digital-caliper-with-sae-and-metric-fractional-readings-68304.html

If you go get one I can walk you through it, but essentially you set the caliper jaws to the MM specified in the manual, tighten down caliper so it doesn't move, flip your carb over (throat down) on a table, take your bowl gasket off and set the caliper guide (slide the caliper rides on) on the tip of the float bowl surface. The top of the float should be touching the slide rule of the caliper.

Here's an older pic that illustrates my terrible explanation above...

http://www.3cyl.com/mraxl/manuals/maint/3-38.jpg

[averysdad]

I should have asked sooner I have one of them I'll try it tomorrow I think I understand basically measuring from bottom of carb to bottom of float. One day I want this bike pulling my arms out of socket but for now need to get it running and put a top end on it lol