Author Topic: 750 motor rmove & install in 2 hours? (Read 5996 times)

grumpy · « **on:** March 24, 2012, 11:23:47 AM »

I've seen posts where people say it takes them an hour to pull a 750 motor and another hour to reinstall.

Really?

OK, maybe an hour to pull it. Maybe.

But an hour to put it back in, rebolt, reistall the carbs, airbox, oil tank & lines, electrical, chain, throttle/tach/clutch cables, exhaust, foot pegs, covers, shift lever, kicker, gas tank, fuel lines, oil filter cover, etc...

C'mon.

MCRider · « **Reply #1 on:** March 24, 2012, 11:29:00 AM »

Quote from: grumpy on March 24, 2012, 11:23:47 AM

I've seen posts where people say it takes them an hour to pull a 750 motor and another hour to reinstall.

Really?

OK, maybe an hour to pull it. Maybe.

But an hour to put it back in, rebolt, reistall the carbs, airbox, oil tank & lines, electrical, chain, throttle/tach/clutch cables, exhaust, foot pegs, covers, shift lever, kicker, gas tank, fuel lines, oil filter cover, etc...

C'mon.

Though i haven't done it in the last few decades, it is possible and routine for those that do it/ did it a lot. The key is to not have the removal and install periods be very far apart. ideally the same day. The longer the delay, the more stuff gets lost etc.

In the shop i worked at we would pull a CB750 in 45 minutes (that was my job) the mechanic would do what was needed, often a head gasket warranty or such, then I'd put it back in. He would get it going. The reinstall shouldn't take more than an hour. An air wrench helps.

excellrec · « **Reply #2 on:** March 24, 2012, 02:17:46 PM »

I've done it in around that time or maybe less. Another large contributing factor is how long ago it was last out. If it's been 30 years.. it probably won't be so easy.

grumpy · « **Reply #3 on:** March 24, 2012, 02:32:33 PM »

Wow.
I'm amazed. It took me about 8 hrs to get it back in and all hooked up.

You guys wanna come over & help?
Free beer!!!!!!!!!!

MCRider · « **Reply #4 on:** March 24, 2012, 02:46:43 PM »

Quote from: grumpy on March 24, 2012, 02:32:33 PM

Wow.
I'm amazed. It took me about 8 hrs to get it back in and all hooked up.

You guys wanna come over & help?
Free beer!!!!!!!!!!

I was talking about a controlled environmetn, with a lot of recent experience. I'd say 4 to 8 hours for someone doing it for the first time, or the first time in decades (me) would be very good.

Just saying a claim of an hour is possible if the stars are aligned.

KC3 · « **Reply #5 on:** March 24, 2012, 03:10:17 PM »

Would much rather be wrenching for 8 hours on my time than be rushed by a BOSS to get it done in under an hour

I used to be haggled every day when I was wrenching for a living...now I looove taking my sweet a%$ time every time I'm in the garage! I'm on my time now buddy! I might just take a month to do a rebuild on purpose just to do everything exactly how I want. Anyways...I digress...Main point being it could take someone an hour; yes, but what's the rush? Crack a beer, and take your sweet time cause we all love being in the garage, right?! Especially when it's your own stuff you're working on!

Cheers!

grumpy · « **Reply #6 on:** March 24, 2012, 03:24:43 PM »

yeah, I understand the difference between working in a a proper shop vs an overstuffed garage with only a crescent wrench and a hammer.

so how would a shop pull the motor? just unbolt it and have one or two guys muscle it out?

KC3 · « **Reply #7 on:** March 24, 2012, 03:27:52 PM »

Depends on the shop--we used to lay the bike down on its side and lift the frame up. (But I was a weakling) I've seen other people who had made a hoist adapter that slid in above the engine and would pull the engine out with the frame sat down on its side. --- Most folks just muscle it out though..two guys can lift one out pretty easily.

MCRider · « **Reply #8 on:** March 24, 2012, 03:34:20 PM »

Yup, 2 guys.

mycb750k6 · « **Reply #9 on:** March 24, 2012, 05:02:24 PM »

I did it in four hours by myself. Since I couldn't lift the motor out at the time, I completely disassembled the bike, laid it on it's side and pulled the frame and the reversed the entire process in 4 hours. Why? The cam cover gasket was leaking after a rebuild and after I'd just put the bike back together. So I waited a few days, took a deep breath and went out and did it. Not bad at all. I will say it helps if you've been through it before though.

MCRider · « **Reply #10 on:** March 24, 2012, 05:04:56 PM »

Quote from: mycb750k6 on March 24, 2012, 05:02:24 PM

I did it in four hours by myself. Since I couldn't lift the motor out at the time, I completely disassembled the bike, laid it on it's side and pulled the frame and the reversed the entire process in 4 hours. Why? The cam cover gasket was leaking after a rebuild and after I'd just put the bike back together. So I waited a few days, took a deep breath and went out and did it. Not bad at all. I will say it helps if you've been through it before though.

I'm impressed...seriously.

Did you get the leak fixed?

lucky · « **Reply #11 on:** March 24, 2012, 05:26:23 PM »

Quote from: grumpy on March 24, 2012, 03:24:43 PM

yeah, I understand the difference between working in a a proper shop vs an overstuffed garage with only a crescent wrench and a hammer.

so how would a shop pull the motor? just unbolt it and have one or two guys muscle it out?

I actually worked in a Honda dealership when the first CB750's showed up at our door. I started with the first Honda Trail 55's and worked up until the CB750's were introduced.
Honda never told us when a new model would arrive.

As far as working on the bikes each mechanic bought their own tools and there were no "bike lifts" at that time. We sat on a plastic milk crate.
Some of the mechanics raced on dirt tracks on Wednesday and Saturdays.
TT racing. There was no motocross in the USA yet.
There were no factory racing bikes. You just built your own acer.

It was years after the first CB750 was introduced that any engines were removed.
I was gone by that time. Even the CB450's were too new for engine removals.
More engines are being removed now and being rebuilt that at any other time in history.

I have recently restored my CB750 and it took days to take the entire bike apart and the engine was the last thing to come out. But after the frame was layed on its side and the engine bolts pulled out the frame came off of the engine on about ONE MINUTE!
To put the engine back in the bare frame it took about 10 minutes so you can be careful to not scratch the frame.

The biggest discovery now days is that it is easier to lower the bare frame over the engine rather than lifting it out with wheels and forks attached.

We did remove some CB350 engines though and we usually removed them and tore them down one day, and the day all the parts showed up we would rebuild them and then put them back in the frame. Since we had other bikes to work on besides the engine removal bike, you would have to look on the time card of the mechanic and then all you would see is that the mechanic punched in at 8AM and punched out at 5PM. You did not punch in and out on each bike. You would just list the parts used and estimate the time it took, and the front office would do the rest.

Things were not that tight back then.

lucky · « **Reply #12 on:** March 24, 2012, 05:30:36 PM »

For the owners that are removing engines and not restoring the motorcycle, I feel
that it is better to have two people lift the engine into the frame. Even a young man has a hard time and if you can rig up a lift of some kind you will save yourself an injury or sore muscles etc.,.

Even without the electric starter the CB750 engine is heavy.

mycb750k6 · « **Reply #13 on:** March 24, 2012, 06:10:02 PM »

Yes MCRider, I fixed the leak

I was just glad it was the gasket and not something serious. Oil was spewing out of the front of the motor on startup. Just goes to show you, there's a lot of oil up there in the cam arena. But the last gasket set I got from sleezebay had the cam cover gasket holes punched so close to the edge I couldn't use it. Didn't want a repeat of that mess.

I use a big C-Clamp rig now for pulling the motor but pulling the frame off the engine is still easier for one person alone. It's just a lot more work. You really do have to take everything apart which is OK for a rebuild but not to change a gasket.

There's a dozen or more threads here with examples of gigs and examples of motor pulling all of which work well. Some of them pretty ingenious.

Gordon · « **Reply #14 on:** March 24, 2012, 06:38:46 PM »

Quote from: KC3 on March 24, 2012, 03:10:17 PM

Would much rather be wrenching for 8 hours on my time than be rushed by a BOSS to get it done in under an hour I used to be haggled every day when I was wrenching for a living...now I looove taking my sweet a%$ time every time I'm in the garage! I'm on my time now buddy! I might just take a month to do a rebuild on purpose just to do everything exactly how I want. Anyways...I digress...Main point being it could take someone an hour; yes, but what's the rush? Crack a beer, and take your sweet time cause we all love being in the garage, right?! Especially when it's your own stuff you're working on!

Cheers!

Damn straight!

I can do good, fast work when it's called for, but I'm a lot more likely to spend all day in the garage and only get the oil changed.

MCRider · « **Reply #15 on:** March 24, 2012, 07:19:04 PM »

Lucky: I don't know why you insist on shooting yourself in the foot over and over. quote:"It was years after the first CB750 was introduced that any engines were removed."

I was working in Honda shops too, starting when i was 17 years old in the fall of 1970. In 4 years time I was in Honda Triumph of Indianapolis, Madison Avenue Honda Triumph (owned by the same guy) Burke's Honda in Ft Lauderdale FL (3rd in US volume sales) and Tri-Onda of Tucson and a drag race shop in Tucson.

From day one of my experience and every few days thereafter there were CB750s with the engines out. Besides many head gasket warranties, there were the broken case warranties. My own new K1 bot in April 1971 was a head gasket warranty. And hotrodding was rampant. Pulling CB750 engines quickly and efficiently was a skill learned quickly by Honda mechanics nationawide in the early days of the CB750 and thereafter.

Terry in Australia · « **Reply #16 on:** March 24, 2012, 07:31:41 PM »

I remove and replace all my CB750 (and Suzuki GS1000) engines on my own, I don't bother with the "strip the frame and lift it off the engine" thing although I've done it once or twice, I just muscle it out on my own.

The most important thing I've learned is to wear good gloves, it's pretty easy to pinch your pinkies when you do it on your own. Cheers, Terry.

MCRider · « **Reply #17 on:** March 24, 2012, 07:36:39 PM »

You da man Terry! I've known a few others who could do that. never actually saw them do it. But one night the engine was in and the next it was out, with no signs of help. Sooo....

I request a pass as the damn thing weighs more than i do.

Terry in Australia · « **Reply #18 on:** March 24, 2012, 07:51:29 PM »

Ha ha, I think that's the thing Ron, I'm around twice as heavy as a CB750 engine, so it's not a real big effort. I remember pulling the engine out of a Harley Sportster for a mate years ago, he was about 5'2" tall and maybe 100 pounds, and freaked out when he saw me pick the engine up and carry it into his house (no garage) so he could rebuild it. Cheers, Terry.

grumpy · « **Reply #19 on:** March 24, 2012, 08:02:32 PM »

Well, I have to retorque my head so the offer still stands.
C'mon over an man handle that bastard outta there!
Free beer!!!!

I used the bar-through-the-frame method to hoist the motor when I installed the new motor. Pretty easy, really.
I just don't want to have to strip & reinstall all the other bits!

Time for a frame kit?

Terry in Australia · « **Reply #20 on:** March 24, 2012, 08:04:04 PM »

Quote from: grumpy on March 24, 2012, 08:02:32 PM

Well, I have to retorque my head so the offer still stands.
C'mon over an man handle that bastard outta there!
Free beer!!!!

I used the bar-through-the-frame method to hoist the motor when I installed the new motor. Pretty easy, really.
I just don't want to have to strip & reinstall all the other bits!

Time for a frame kit?

Ha ha, you pay the return airfare mate, and I'm there!

MoMo · « **Reply #21 on:** March 24, 2012, 10:48:53 PM »

Quote from: MCRider on March 24, 2012, 07:19:04 PM

Lucky: I don't know why you insist on shooting yourself in the foot over and over. quote:"It was years after the first CB750 was introduced that any engines were removed."

I was working in Honda shops too, starting when i was 17 years old in the fall of 1970. In 4 years time I was in Honda Triumph of Indianapolis, Madison Avenue Honda Triumph (owned by the same guy) Burke's Honda in Ft Lauderdale FL (3rd in US volume sales) and Tri-Onda of Tucson and a drag race shop in Tucson.

From day one of my experience and every few days thereafter there were CB750s with the engines out. Besides many head gasket warranties, there were the broken case warranties. My own new K1 bot in April 1971 was a head gasket warranty. And hotrodding was rampant. Pulling CB750 engines quickly and efficiently was a skill learned quickly by Honda mechanics nationawide in the early days of the CB750 and thereafter.

Plus there was the case recall that gave the mechanic 18 hours (at least that is what my memory recalls) to pull the motor, totally tear the engine apart and install all the old parts into the new cases. And there were the proverbial "I'll slam this baby from first to second gear and see how quickly I can ruin the trans" repair. Can't tell you how many of those I did in the early 70's

. Two men muscled the engine out and put it back in, still what I do to this day. Once everything is disconnected it is a matter of minutes...Larry

trueblue · « **Reply #22 on:** March 25, 2012, 03:24:00 AM »

Quote from: Terry in Australia on March 24, 2012, 07:31:41 PM

I remove and replace all my CB750 (and Suzuki GS1000) engines on my own, I don't bother with the "strip the frame and lift it off the engine" thing although I've done it once or twice, I just muscle it out on my own.

The most important thing I've learned is to wear good gloves, it's pretty easy to pinch your pinkies when you do it on your own. Cheers, Terry.

I pulled the engine out of my 650 by myself with it sitting on the centre stand, it was heavy but not unmanagable, but as Terry said use a good set of gloves, I didn't and had a couple of good bruises on my hands. According to my Clymers manual, the engine assembly weighs 71kg, I stand 6'1" and weigh 72kg. When I reinstalled I slipped the bare frame over the engine then built the bike around that.

andy750 · « **Reply #23 on:** March 25, 2012, 08:44:56 AM »

In the Fall I dismantled Ken in Newports K1 for him and we had the engine out in under an hour. 2 people to lift it out. Ive done this several times now on my own 2 CB750s and its easy enough now. Reassembly gets faster every time. The frame kit does help for the top end leaks.

Record so far is stripping the bike in the morning (starting at 9am), splitting the bottom end, running around trying to find parts, clean and paint the engine, reinstall, reassemble and all done by 11pm. Then riding back home for 50 miles. That was a long day

.

Have also done rode up to NH, pulled the engine, replaced valve retainers, pucks etc reinstalled engine, reassembled bike and left the next day.

Can be done. Good luck Grumpy!

cheers
Andy

Skonnie Boy · « **Reply #24 on:** March 25, 2012, 11:26:55 AM »

Didn't pull the engine alone, but I sure put it back in alone. Its like wrestling a dead person. Not recommended.

All you need for this unwise endeavor is cardboard, unimportant lawn and a willingness to part with some of your lesser digits and their knuckles. Drafting tape and towels help keep parts of the frame unscratched.

But I'm not a big guy, so heed this advice as needed.

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Author Topic: 750 motor rmove & install in 2 hours? (Read 5996 times)