Author Topic: Engine Experts - 1st Ride VIDEO (Read 2301 times)

Kouros · « **on:** August 28, 2011, 11:16:39 AM »

I finished as much work as possible on this 74 CB750 and then gave it Lossa Engineering to rebuild and tune the carbs, and perform the first start as I did not have confidence with my mechanical skills. I just got motorcycle back. I did not crack the case or do and top engine work because 3 years ago the motorcycle ran fine (at least in my opinion). But the valve cover was open for a year and all taped up and covered up.

Now there is much noise coming from what it sound like to be the valves. I need advice as to what to do.

Other issues are:
Battery fluid drained about an 1/2 ounce through its breather hose
I can't find Neutral (possibly due to bar end mirror in the way of clutch lever)
Brake Bleeder bolt is leaking
Fuel leaks at carb due tonot having fuel hose clamps

Any advice in regards to the battery and the engine noise is much appreciated.

Kouros
Honda CB750 FOUR K4 First Ride

Kouros · « **Reply #1 on:** August 28, 2011, 12:00:27 PM »

Question:
How much oil should be in the oil Tank when the bike is upright and is left over night and cold? Just the tip of the dip stick is wet right now.

ekpent · « **Reply #2 on:** August 28, 2011, 12:27:57 PM »

The only time to accurately check the oil is after the engine is warm and the oil has been run up into the tank. If the check valve is not working correctly like a lot of these bikes then it will run back down into the engine when it sits.

pknopp · « **Reply #3 on:** August 28, 2011, 05:49:22 PM »

First, that's a killer looking bike. I really like it. Also, it sounds good from here.

I've never had a battery puke on me, so I don't know. I don't know your experience or your bike. I'm generalizing. It can be sort of hard on ocassion to find neutral on an old bike sitting still. I know on my 750 I sometimes have to roll forward in first a bit to get it to go into nuetral.

Um, add clamps to the fuel lines........ Again I do not know your experience. The bike seemed to run and sound good in the video. If you are used to newer water cooled bikes they will be quieter. It's part of the reason I dont care for them. I like to hear the stuff working in an air cooled bike.

VTCBike750 · « **Reply #4 on:** August 28, 2011, 05:55:55 PM »

Maybe try resetting the valves? The valves do sounds like giant sewing machines. I didnt hear anything outright, but Im no expert.

What oil are you running in it? I had an issue finding neutral with cheap automotive 10w-40 in my bike. I swapped it out for quality motorcycle oil, I wont get into what kind, dont wanna start a war of words.

I also modified the clutch hub, replaced the oil pump o-rings, and replaced the countershaft bearing oiler seal:
http://forums.sohc4.net/index.php?topic=78643.0
Its great now. But then again it may just be your mirror or the clutch needs adusting.

Maybe take out the bleeder bolt, clean it with steel wool, and see if it then seals?

None of my carbs have hose clamps and no leaks.

andy750 · « **Reply #5 on:** August 28, 2011, 06:18:48 PM »

Sounds like a loose camchain to me. That or clutch is way out - clutch rattle at idle - check this by pulling in clutch lever and see if noise goes away or lessens.

Alternatively check for exhaust clamp leaks at the spigot.

I am sure the guys at Lossa would know all these things though...

Good luck
Andy

MCRider · « **Reply #6 on:** August 28, 2011, 06:19:56 PM »

Check if the battery hose had any chance of dripping on your chain, like when its leaned over on the sidestand. Even fumes are an issue. If so, you need to square away the battery issue and think about replacing the chain. Once its been fouled with battery acid it is irretrievable and likely to break. Hyfrogen embrittlement. Google it for more info if necessary.

The fuel lines shouldn't leak even without clamps. possibly the ends of the hoses have hardened with age and lost their ability to seal. The clamps should be retored for safety sake, but not to stop the leaking. That's a hose issue.

Duke McDukiedook · « **Reply #7 on:** August 28, 2011, 07:42:46 PM »

Something is noisy on that, either valves or cam chain or clutch chatter- something ain't right sounding.

10-15 minutes after shut off after the bike has been run to normal operating temperature is the proper time to check for oil in the tank- should be up to the top of the checkered area on the dipstick if it is full.

Kouros · « **Reply #8 on:** August 28, 2011, 11:08:26 PM »

Nice! Thanks for the reply so far and thanks for the compliment.
Well, the update is that the battery is not leaking. I have no chain-guard and the lube was all over the inner fender so it dripped on the battery hose, sliding down. On my second ride so far, I was taking it easy, but almost lost it when it slipped due to the grease on tires.

So regarding the noise. IMO it could be the clutch, although pulling the clutch lever does not get rid of the sound. I did notice when I just kept circling the neighborhood that after a while and at steady RPM (~3.5K) it almost went away. Not sure if the folks at lossa poured oil from the top or properly primed the engine before first start because we didn't talk about it.

Oil Check was at the bottom 1/3 of the checkered.

Could it be oil not reaching someplace at idle or until it warms up?

I think I'm going to go for a few more turns tomorrow to get rid of more lube on the chain and to see if I can reproduce the sound going away or less.
Cheers,
-K

WarwickE36 · « **Reply #9 on:** August 29, 2011, 08:23:31 AM »

Loose primary chain? I am in the middle of a rebuild for a loose primary on my 550. It was a ticking/tapping coming from the lower end. Sound diminished (or seemed to...) with revs.

I would check valve lash as well, especially if it hasn't been touched in 3 years.

bollingball · « **Reply #10 on:** August 29, 2011, 08:51:47 AM »

If you use the 5.5mm (id) fuel line you will not have to use clamps. I would guess you have 1/4" line that is to loose and will need clamps. Your noise sounds like cam chain IMHO. Lossa should have fixed every thing but the fuel lines (they would need your tank to put the correct size on) depending on your agreement at the beginning.

crazypj · « **Reply #11 on:** August 29, 2011, 08:53:21 AM »

Sounds like you need to take it back and make them do it properly.
When the rattling is louder than the exhaust, there is a MAJOR problem.
Most likely they gave it to 'new guy' who set valves on overlap and also didn't know how to adjust cam chain.
(Iused to teach servicing and had some real good arguments with people when thy insist they did it right, at TDC

)
I wouldn't run engine until they fix it.

Warwick, it aint a 550, your comment is worthless
Check main oil gallery on 550, primary chain can wear a slot in it (then you have zero oil pressure to mains/big end bearings)

Tews19 · « **Reply #12 on:** August 29, 2011, 11:18:55 AM »

+1 on bringing it back to the shop... Hard earned money spent on a great looking bike.... It should run better and if you are having concerns already, that isnt good... I would wait to drive until fixed.... Nothing more discouraging than seeing your bike in the garage and not working running right.....PLus everytime you ride it and wonder if the shop did their best work for all the money you spent, that anger will build up and you may go off the deep end.... sweet looking bike though

Really? · « **Reply #13 on:** August 29, 2011, 01:12:21 PM »

Other than the noise yer asking about, I like the sound (yanno, the exhaust) and the bike is perty. Might even see it show up for BOTM in the future. I hope so!

Kouros · « **Reply #14 on:** August 29, 2011, 01:33:40 PM »

I'll be calling The garage. The agreement was to just prepare the engine for a first start, meaning all the priming, Timing, Cam chain tensioner, Carb cleaning, tuning and jetting. He was not suppose to work on the engine. But I can't remember this noise 3 years ago. Its so loud that it would have been sticking in mind all along.

on the other hand, worthy on just mentioning here.....Some of my friends who heard what you heard on the video and who have not read this thread suggest that it might be the clutch sticking due to sitting a long time. Any thoughts on that?

Appreciated all the replies, please keep it coming.

-K

Duke McDukiedook · « **Reply #15 on:** August 29, 2011, 01:35:59 PM »

If the noise didn't change with the clutch being pulled in then I would assume a noisy cam chain or tappets. I would check there.

MCRider · « **Reply #16 on:** August 29, 2011, 02:07:30 PM »

I've never known a sticky clutch to be noisy. It usually makes it hard to shift, find neutral, start, etc.

I still vote for the cam chain tension. As someone pointed out an uninformed mechanic may have adjusted it improperly. Remember the 500/550s are set with the engine running. Even some 750 manuals say to set it while running.

My experience is if that is done on a 750 its likely to result in a very noisy cam chain. Even though the mechanic read it in a manual.

There was a thread on this in which the advice to set the CB750 chain "dynamically" was confirmed in print. But I don't believe it can work that way. At least not and achieve the best result...a quiet chain.

Tews19 · « **Reply #17 on:** August 29, 2011, 02:14:27 PM »

Quote from: MCRider on August 29, 2011, 02:07:30 PM

I've never known a sticky clutch to be noisy. It usually makes it hard to shift, find neutral, start, etc.

I still vote for the cam chain tension. As someone pointed out an uninformed mechanic may have adjusted it improperly. Remember the 500/550s are set with the engine running. Even some 750 manuals say to set it while running.

My experience is if that is done on a 750 its likely to result in a very noisy cam chain. Even though the mechanic read it in a manual.

There was a thread on this in which the advice to set the CB750 chain "dynamically" was confirmed in print. But I don't believe it can work that way. At least not and achieve the best result...a quiet chain.

God, not to hijack the thread but to adjust the cam tensioner on 550's the bike has to be running? really?

MCRider · « **Reply #18 on:** August 29, 2011, 04:17:20 PM »

Quote from: Tews19 on August 29, 2011, 02:14:27 PM

Quote from: MCRider on August 29, 2011, 02:07:30 PM
I've never known a sticky clutch to be noisy. It usually makes it hard to shift, find neutral, start, etc.

I still vote for the cam chain tension. As someone pointed out an uninformed mechanic may have adjusted it improperly. Remember the 500/550s are set with the engine running. Even some 750 manuals say to set it while running.

My experience is if that is done on a 750 its likely to result in a very noisy cam chain. Even though the mechanic read it in a manual.

There was a thread on this in which the advice to set the CB750 chain "dynamically" was confirmed in print. But I don't believe it can work that way. At least not and achieve the best result...a quiet chain.

God, not to hijack the thread but to adjust the cam tensioner on 550's the bike has to be running? really?

Well. not according to the manual. My fault, bite my tongue.

But according to some 500/550 guys like TwoTired, its a method that can be used. So i mispoke saying or implying it was the primary method. My apolgies.

But it can be done running. And I think some mechanics may default to running, which renders the 500/550 quiet quickly. But its tensioner is completely different from the 750.

Which I don't think is a good idea on CB750s. But there i know others do it and say its fine.

http://forums.sohc4.net/index.php?topic=76359.0

In the case of the problem at hand, the tensioner should be removed and inspected. And then the chain should be adjusted in the manner which yields the tightest chain within the limits. Hopefully that will quiet things down. Otherwise, it may have a tensioner slider or wheel that has come apart rendering adjustment not possible.

crazypj · « **Reply #19 on:** August 29, 2011, 06:35:08 PM »

If it's cam chain it should quiet down slightly as engine gets hot (and head 'moves away' from crank)
Whatever, I would have been ashamed to let a bike sounding like that leave the shop.
It was either like it when you parked it or they screwed something up.
I've heard of people adjusting cam chain with engine running, never worked for me on a 750

Kouros · « **Reply #20 on:** August 29, 2011, 10:46:56 PM »

Def sound fading away as it get hotter.
CrazyPj, All the rest of the stuff you addressed about the shop, is another entire thread for another day.

-K

N30R3L0AD3D · « **Reply #21 on:** August 30, 2011, 11:01:55 AM »

Sounds to me like your cam chain and tentioner need to be replaced. That sounds horrible at idle.

Kouros · « **Reply #22 on:** September 01, 2011, 10:25:59 AM »

I tried to fix/troubleshoot the noise. I don't have the markers through the peephole to TDC #1 and clockwise 15 degrees. So we made sure visually both valves are closed on cylinder #1 and that the cylinder all the way up. Then loosened the cam adjuster lock-nut, opened the screw and the bolt dropped in. tighten everything back, started the engine and the sound was almost gone. It still makes some noise, but I think comparatively, I hear that on most videos I hear on this forum. I have no way of gauging because the last time I was close to one these sohc's running was many years ago.

Does above sound right? Did I do the right thing?
____________________________________________________

Another issue is I can't find the neutral gear while the bike is running. I can find it while the bike in off. I am using rear sets and I wonder if the mechanism of the rear sets have anything to do with this!

Any advice would be appreciated as always.

-Kouros

MCRider · « **Reply #23 on:** September 01, 2011, 10:32:01 AM »

Curious as to why you don't have markers and the spring post visible thru the peephole? Short of that you done good. That little extra bit of 15° past tdc really adds to the adjustment, vs just tdc. So hope you got that.

As to hard to find neutral, my experience is that's usually sticky clutch plates. Does it want to move forward when you drop it into first from neutral?

Certainly rearsets changes the geometry and leverage, so you have to allow something for that. But I vote for a sticky clutch.

See reply #16 above.

Kouros · « **Reply #24 on:** September 01, 2011, 02:48:46 PM »

MC,
You're right on the money. The bike wants to jump forward when I drop to first (from neutral or second).
Only way I can get to neutral now is to shut it off, go to neutral and restart. I will look into learning how to change the clutch. I don't know why it is, but with my very limited mechanical skills, I have a higher rate of successfully completing tasks than Paid mechanics (who end up on TV shows) ;-|

Thanks bro!

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Author Topic: Engine Experts - 1st Ride VIDEO (Read 2301 times)

bollingball