Priming the oil pump?

[xlr8r]

I checked the pump's clearances (on the first rebuild) and primed it to get the oil moving through it. Clearances were great. Where I think I screwed up was a combination of things: Because I was busy with work it took about a week or so before I was able to do the valve clearance adjustment. Between taking a few rotations to find TDC for the cam/timing chain instalation and then taking a few rotations to find TDC to do the valve clearance, I must have drained the oil pump. Oh, again, I hadn't put oil in the bike prior to doing the valve adjustment. Yes, stupid, but not totally unthinkable (until now). From now on I will always loosen the top nut on the oil feed tube at the top end to check for oil preasure, before I take off down the road. New piston and cylinder are on their way though. I have another question about other potential damage from seizing which I'll post in a new thread. Thanks for taking it easy on me though. I very fragile right now.

[jclaus98]

Davey sprocket, totally unrelated, but where did you get that header pipe?? Is that a stock thing or did you get that from somehwere aftermarket???

[DaveySprocket]

...If it is tight without gouges from trying to pump metal bits, it will self prime...

It should, but I would not bet an engine on it?

When I had the problem with the pump failing to prime after rebuilding my 600, that was with a brand-new factory oil pump.

[DaveySprocket]

Davey sprocket, totally unrelated, but where did you get that header pipe?? Is that a stock thing or did you get that from somehwere aftermarket???

FMF stainless header?

[XR650L_Dave]

I don't think that this is true. I bet that most shops don't do it at all. I have had several RFVC engines apart and I didn't know about priming the pump and they ran for years. The shop manual tells you to put moly paste on the cam and rocker arms, just for the lack of oil at the first start.

I think one important thing is the condition of the pump. If it is tight without gouges from trying to pump metal bits, it will self prime. A lobe pump is positive displacement. The air gets pumped out and the vacuum draws in the oil. If it is loose, it can't "pump" the air out and the oil doesn't flow. The air just leaks around the extra clearance and stays in the pump.

I was referring to folks who get a bike straight from the factory, and pretty soon, seizola! It happens once in awhile.

Dave

[Beyond The Pale]

I now know why I always loose in Vegas. All my luck got used up when first starting non primed rebuilt engines...

I'll be positively priming my engines from now on.?

[thecirque]

Apparently I'm one of the guys that was lucky enough to have my oil pump "just start working" after rebuild. I couldn't figure out how to prime so I just went for it. I started and stopped the bike a few times trying to warm up the bike without really heating it up thinking the oil would settle through it.

It all worked out. I wish I would have have seen this thread before hand I would have taken a bit more time and primed it properly.

Live and learn....and count my blessings.

[bsa441]

use engine assembly lube in oil pump [or lucas synthetic or regular oil additive] tacky stuff , ensures good pull , pressurize frame with 10 to 20 psi , stroke motor through several times. Screen filters as in the frame can take time to develope capilary action to attain full flow , especially after a through cleaning.

[crmc33]

Ive wrecked two race cams cos of not priming the pump?

Im currently rebuilding my motor and will take more care this time.

Lumpy race cams are even more sensitive to lack of oil as you would expect.

Before I start the engine in the Spring I'll be checking the oil supply at the top of the oil feed pipe (Ive even had a new custom braided hose for this to make sure) and....

I'll check the return scavenge pipe from the engine to the oil tank. If you can see youre getting oil pumped back to the oil tank then there should be plenty of pressure to the cams and rest of the engine. This is a trick used on old classic racing engines such as Manx Nortons. Obviously this means turning the engine over for quite some time before oil is scavenged back. I will do this by pushing the bike down the road (in gear) with the spark plug out (no electric/kick starter).

I'll update you all on how it goes come start up time - Im hoping for 60HP+ from this engine (lots of head work done) so I hope it lasts longer than the 36 race miles the last cam survived for!!

[oldchvytrx]

Hey,

I'm rebuilding my 650L engine and was wondering if there is a specific way (if it is even necesary) to prime the oil pump. I oiled the hell out of everything on assembly but it still scares me to pull the trigger. Thanks!

<<<<<<<>>>>>>>>

A little trick imparted to me by one of the first factory certified Honda mechanics in the US.... I still use it and have never had a problem getting the pump to pick-up quickly. When you disassemble the pump to check clearances pack it with petroleum jelly (Vaseline) and reassemble and install. On the "L" be sure and pack both sides, main and sump scavenging.

Leave the spark plug out, leave the oil line loose (banjo bolt) on the rocker cover and spin with the starter until oil flows (probably less than a minute). Tighten the banjo bolt and spin it for anther few seconds before installing the plug and fireing it up. Make SURE you use a good moly assembly lube on the rocker faces, cam lobes and the cam's center support bearing.

The Vaseline will just disolve into the oil. If your woried about the parrafin it contains change out the break-in oil after about 100 mile or so but the amount is so small it doesn't cause a problem.

?

[asf]

PLEASE, don't do this until you hear it from somebody smarter than me ... I don't now if this is a good idea or not, but on MY OWN bike, I would yank the spark plug, and spin the engine with the starter, to pick up it's prime ... would this work?, or is it risky ? ...

I am about to fire up a fresh rebuild and was told the same thing, but I dont have the magic button on my r so just kick it over with the manual decompression lever pulled and the top oil tube banjo unbolted till it leaks oil. I've already poured a quarter quart into the top end via the return line to the frame and filled the filter housing so I know there is oil there for now.

If you do pull the plug, be very careful where you dangle it. If it grounds I have seen some pretty big guys go flying across the floor.....

[mgs781]

All bikes have kill switches, there is no need to pull the plug.

After my engine rebuild, I primed the pump with the starter and the kill switch, worked - engine didn't blow up.

MGS

[XR650L_Dave]

Yankin' the plug just lets it spin faster, and for a long time w/o draining ther battery.

Dave

[timothypg]

when i did my rebuild i took out the filter and used one of those baby ear washer bulb syringe things and squirt a bunch of oil down into the oil passage lower left, seemed to work for me

[oldchvytrx]

Yankin' the plug just lets it spin faster, and for a long time w/o draining ther battery.

Dave

<<<<<>>>>>>

Exactly what I was going to say Dave.

:ride:

[oldchvytrx]

All bikes have kill switches, there is no need to pull the plug.

After my engine rebuild, I primed the pump with the starter and the kill switch, worked - engine didn't blow up.

MGS

<<<<<<<<>>>>>>>>

True you don't have to pull the plug BUT, if you have a Wiseco Hi Comp piston and a cam that eliminates the comp release your battery won't crank for long. Your much better off to just leave out the plug and crank it till it primes.

:ride:

[mgs781]

<<<<<<<<>>>>>>>>

True you don't have to pull the plug BUT, if you have a Wiseco Hi Comp piston and a cam that eliminates the comp release your battery won't crank for long. Your much better off to just leave out the plug and crank it till it primes.

:ride:

I do have a Wiseco 10.25:1 piston with Hot Cams Take a look at my bike sport, I think I know what I am doing!

You don't have to pull the plug with e-start, just crank for a few 10 second bursts, works really good. I am even using a smaller than stock battery.

Do whatever you want, just seems like extra work to me.

MGS

[oldchvytrx]

I do have a Wiseco 10.25:1 piston with Hot Cams Take a look at my bike sport, I think I know what I am doing!

You don't have to pull the plug with e-start, just crank for a few 10 second bursts, works really good. I am even using a smaller than stock battery.

Do whatever you want, just seems like extra work to me.

MGS

<<<<<<<<>>>>>>>>

Lighten up "Sport" , didn't say you didn't know what you're doing, just that the starter will spin longer and faster with less strain and wear on everything. It will also prime the engine MUCH faster than 10-15 sec "bursts" and pulling a plug as extra work? You've just reassembled the engine, just leave the darned thing out till you spin it and prime the pump, how much "extra work" is that? I usually prime and test fire before doing the final assembly of body work on the outside chance I might have to correct something.

I use the "plugless" method because not all the Honda Thumpers I work/worked on have electric start. My first was a brand spankin new 1972 XL 250. This one ended up making a dynoed 38hp with the full Yoshimura treatment. Try "kickin" this 12.5 slugged dude over with the plug in long enough to prime it!

I've been building/rebuilding engines for about 35 yrs and think I've got a clue how to do it right as well, but like you said, "do whatever you want."

:ride:

[bork]

<<<<<<<<>>>>>>>>

Lighten up "Sport" , didn't say you didn't know what you're doing, just that the starter will spin longer and faster with less strain and wear on everything. It will also prime the engine MUCH faster than 10-15 sec "bursts" and pulling a plug as extra work? You've just reassembled the engine, just leave the darned thing out till you spin it and prime the pump, how much "extra work" is that? I usually prime and test fire before doing the final assembly of body work on the outside chance I might have to correct something.

I use the "plugless" method because not all the Honda Thumpers I work/worked on have electric start. My first was a brand spankin new 1972 XL 250. This one ended up making a dynoed 38hp with the full Yoshimura treatment. Try "kickin" this 12.5 slugged dude over with the plug in long enough to prime it!

I've been building/rebuilding engines for about 35 yrs and think I've got a clue how to do it right as well, but like you said, "do whatever you want."

:ride:

Hehehehe:thumbsup:

[mgs781]

<<<<<<<<>>>>>>>>

Lighten up "Sport" , didn't say you didn't know what you're doing, just that the starter will spin longer and faster with less strain and wear on everything. It will also prime the engine MUCH faster than 10-15 sec "bursts" and pulling a plug as extra work? You've just reassembled the engine, just leave the darned thing out till you spin it and prime the pump, how much "extra work" is that? I usually prime and test fire before doing the final assembly of body work on the outside chance I might have to correct something.

I use the "plugless" method because not all the Honda Thumpers I work/worked on have electric start. My first was a brand spankin new 1972 XL 250. This one ended up making a dynoed 38hp with the full Yoshimura treatment. Try "kickin" this 12.5 slugged dude over with the plug in long enough to prime it!

I've been building/rebuilding engines for about 35 yrs and think I've got a clue how to do it right as well, but like you said, "do whatever you want."

:ride:

I understand I came down too hard, my fault, please accept my appology.

MGS