Author Topic: Rip Van Winkle; Waking up a K4 (Read 9384 times)

Beergineer · « **on:** November 20, 2016, 10:19:00 AM »

Some back story:
I bought this bike about 6 years ago in near running condition (I had gotten it to start, but never to run more than a few seconds). It has since moved with me from Central NY down to Pittsburgh, and out to the suburbs. It is time to get this K4 back on the road.

Goal: Make the bike run in a mostly stock manner.

You're welcome to suggest boring it out to 1000cc and swapping a gsxr front end, but that just isn't going to happen.

Last winter I disassembled everything in order to sandblast and powder coat most of the components. I also copied Gordon's bolt-in frame mod (Sorry and Thanks Gordon). So I've got the engine out with the following components PC'd: frame, fork lowers, triple trees, battery box, engine brackets, swing arm, chain guard, brake caliper pieces and brackets, and probably some other things that are wrapped in newspaper under the work bench.

Since I have the whole bike disassembled I'm going to need some help/suggestions on the best order to reassemble things. Please feel free to raise red flags and offer up the lessons you've learned the hard way (I'd prefer not to do the same).

Here is the current state of affairs:

Beergineer · « **Reply #1 on:** November 20, 2016, 10:50:10 AM »

I've taken the valve and side covers off to do a general inspection. I've got allen bolts ordered and will be buying a complete top end gasket kit, just in case. I don't want to go any further into the engine if it isn't warranted.

Are there any recommended measurements and PM to do in this state?

This link Shows the valve train turning and the cylinder compression:

b52bombardier1 · « **Reply #2 on:** November 20, 2016, 12:14:39 PM »

Did you run any compression checks back when it was assembled? In other words, what PSI did you see with the throttle held wide open and the engine vigorously cranking? That could strongly suggest your next course of action. At this point, I would get all cylinders measured for diameter, taper and out of round for a possible bore job. Don't buy anything until a truly competent machinist with calibrated measuring tools can give you advice.

How many miles on the bike?

I'd also probably measure the cam and other top end parts for wear.

Rick

Beergineer · « **Reply #3 on:** November 20, 2016, 12:33:57 PM »

Thanks for the response b52. I did not run any compression checks before disassembly, is there a decent 'how to' on setting up a bench test of these engines? I have all the electricals to make it crank.

However I have no reason to believe there is anything wrong with the engine. It has around 20,000 miles on it, and from the look and condition of the old gaskets I think I'm the first person to open this engine up. I have learned my lesson about fixing things that aren't broken, which is why I'm hesitant to undo the head nuts.

Worst case scenario: I reassemble the bike, the top end needs to be rebuilt, and I do it with the engine in the frame.

b52bombardier1 · « **Reply #4 on:** November 20, 2016, 03:13:41 PM »

I think somebody around here recently did a bench run thread. For a simple compression check, I'd simply apply power to the the starter with the carbs removed. After a nearly 40 year slumber, my cylinders were around 145 psi each - no rebuild required. I'd worry at around a hundred psi but it should at least run though it'll probably smoke.

Rick

Sent from my SAMSUNG-SM-N900A using Tapatalk

calj737 · « **Reply #5 on:** November 20, 2016, 06:03:19 PM »

I wouldn't pull the engine down with only those miles on it. Any evidence of significant leaks? I would check the cam towers and head nuts for proper torque while you have the cover off and engine out. Probably good to replace the rubber pucks too.

You might do well to invest in Hondaman's book (available through a link in the "Site Sponsors" area. It's filled with great info about small mods to make for improved reliability, measurements, and tuning procedures. It runs about $75 and well worth it.

Beergineer · « **Reply #6 on:** November 21, 2016, 04:49:27 PM »

Cal, there isn't any evidence of leaks and I don't believe I removed any evidence since I've owned the bike. Before I go torquing anything I'm going to do a compression check (Time to find out if I have the right spark plug adapter). If the compression is good, I won't touch anything. Speaking of 'good' compression, the manual says the spec is 170psi, B52 says that 145 was fine and that 100 is concerning. Are there any other opinions on acceptable compression values?

The internet told me that the compression can be checked by turning the crankshaft with a power drill & socket, and a co-worker tells me his dad routinely checks 4 cylinder (car) Honda motors by just turning them over with a ratchet. I'm going to try the ratchet method first just to see what I get, and then move onto the power drill if I don't hear any objections.

calj737 · « **Reply #7 on:** November 21, 2016, 06:55:31 PM »

Compression tests are inconclusive. They point to a rating between the cylinders and can be misleading. Ideally, you'd see less than a 10% delta among all four cylinders. But, if the motor has sat a while, you may see low numbers. If your carbs are not fully opened, you can see low numbers. If there's carbon build up on the valves, you can see low numbers.

I look at this way: if the motor looks "stock" and does not appear to have been opened, if there's little to no indication of oil leaks, and the oil smells good and runs clear, I expect the compression and health of the motor to be good. If I want an investigative test, I use a leakdown test. It tells a great deal more about what and where is leaking.

Use a fully charged and healthy battery to spin the motor. I doubt an electric drill will spin the motor fast enough to generate high enough readings. Maybe...

Beergineer · « **Reply #8 on:** November 22, 2016, 06:19:11 PM »

Turns out I don't have the right spark plug adapter. Looks like compression testing will have to wait until next week.

Beergineer · « **Reply #9 on:** November 30, 2016, 04:13:13 PM »

I borrowed the right adapter from a coworker. The drill method does work, however I found that I have no compression in Cylinder 1. After dinner I will leak test the cylinder with my makeshift leak tester (Compressor>regulator>compression test hose>conveniently sized screw>spark plug adapter). I'll let you guys know what I find.

Side note: while taking parts inventory it looks like I'll be having a nightmare with old rusty screws/nuts/washers. Does anybody have a good/inexpensive source for buying metric hardware online?

calj737 · « **Reply #10 on:** November 30, 2016, 04:15:38 PM »

www.boltdepot.com
www.allensfasteners.com
There's other sites that sell complete socket head cap screw kits for the engine side covers and valve covers too if you wish to replace those.

Beergineer · « **Reply #11 on:** November 30, 2016, 04:48:19 PM »

Thanks for the links. I already ordered stainless allen head screws for the engine, I figured if any of those phillips screws were coming out it wouldn't be worth trying to reuse them.

calj737 · « **Reply #12 on:** November 30, 2016, 05:12:27 PM »

There's your issue; those aren't Phillips, they're JIS. And JIS screws have a very different pitch to them. If you are apt to rebuild another Japanese vintage bike. Purchase yourself a set of Vessel screwdrivers from http://www.rrrtoolsolutions.com/index.php They will make short order of removing them without damage and the Impacta driver works a treat for unsticking stuck/stripped screws.

Beergineer · « **Reply #13 on:** November 30, 2016, 05:38:49 PM »

I know they're JIS. I found a good fitting screw bit and used my corded drill to remove them. I had about a 95% success rate, but still had to drill a few.

Leak testing showed that at TDC on cylinder one both the exhaust and intake valves were open. I checked the tappets and sure enough there was 0.000" of clearance. I set them quick to a piece of paper (~0.003"), repeated the compression test and the gauge read 150 psi.

I will borrow a set of feeler gauges from work tomorrow and properly set the clearance on all the tappets and see how close all the cylinders are to each other.

Beergineer · « **Reply #14 on:** December 01, 2016, 06:37:17 PM »

OK. Tappet clearances are set properly. Did another compression test and got the following results:

#1- 142 psi
#2- 144 psi
#3- 142 psi
#4- 140 psi

This was with an automotive gauge, which explains the lower than 'spec' numbers. They don't concern me, so I'm going to call the engine good to go. Unfortunately when I opened up the gasket kit I ordered I found the valve cover gasket was broken. So I'll need another one of those before I move forward.

RAFster122s · « **Reply #15 on:** December 01, 2016, 10:12:54 PM »

Hope the place that you bought the gasket set makes good on the gasket.
what brand did you buy?

calj737 · « **Reply #16 on:** December 02, 2016, 03:05:55 AM »

Quote from: Beergineer on December 01, 2016, 06:37:17 PM

OK. Tappet clearances are set properly. Did another compression test and got the following results:

#1- 142 psi
#2- 144 psi
#3- 142 psi
#4- 140 psi

This was with an automotive gauge, which explains the lower than 'spec' numbers. They don't concern me, so I'm going to call the engine good to go.

That is very good results. I would fully expect those numbers to jump up after some good running, heat cycles, and a good old fashioned Italian tuning

grcamna2 · « **Reply #17 on:** December 02, 2016, 05:52:15 AM »

Have a look at your rubber cam chain tensioner rollers before you start it,the rubber gets rock hard on some of them over age and they begin chewing-up and leaving pieces inside your engine.

Beergineer · « **Reply #18 on:** December 07, 2016, 03:49:21 AM »

While I'm waiting on a new valve cover gasket I turned my attention to the wheels. You can see that side conversation here:
http://forums.sohc4.net/index.php/topic,162458.0.html

With a little luck I'll be able to re-use the spokes from the 17" rear, so I don't have to source new spokes. The next order of business should be to put the covers back on, fit a centerstand on the frame, re-install the engine, and get it into 'roller' status.

grcamna2 · « **Reply #19 on:** December 07, 2016, 08:01:35 AM »

Show us some pics

Stev-o · « **Reply #20 on:** December 07, 2016, 04:42:42 PM »

Quote from: Beergineer on November 30, 2016, 05:38:49 PM

I know they're JIS. I found a good fitting screw bit and used my corded drill to remove them. I had about a 95% success rate, but still had to drill a few.

I always use an impact driver and have 99% success rate. Plus I like using my big-ass hammer to bang the driver!

Restoration Fan · « **Reply #21 on:** December 10, 2016, 03:47:18 AM »

Quote from: Stev-o on December 07, 2016, 04:42:42 PM

Plus I like using my big-ass hammer to bang the driver!

Stev-o,
I don't think we're supposed to have conversations like that on this forum.

calj737 · « **Reply #22 on:** December 10, 2016, 04:28:57 AM »

Quote from: Restoration Fan on December 10, 2016, 03:47:18 AM

Quote from: Stev-o on December 07, 2016, 04:42:42 PM
Plus I like using my big-ass hammer to bang the driver!
Stev-o,
I don't think we're supposed to have conversations like that on this forum.

If anyone wants me, I'll be running to my "Safe Space"

Beergineer · « **Reply #23 on:** December 11, 2016, 01:28:59 PM »

Sorry for the lack of updates, but my 'safe space' has been invaded the past two weekends by various out of town guests.

During that time I did receive a new valve cover gasket, a proper spoke wrench, tire spoons and rim savers. Spokes have been soaking in PB Blaster for a few days so the old tires will come off and the spokes/hubs/rimstrips will get a proper inspection.

Hopefully next update will be the engine all buttoned up and transferring rear brake and axle hardware from the stock 18" wheel to the 17" wheel.

Pictures will come once there is something worth seeing.

Beergineer · « **Reply #24 on:** December 11, 2016, 06:59:36 PM »

Good news: Clutch cover, valve cover, starter motor cover and points cover all installed with fresh gaskets and stainless Allen screws.

Bad news: I think the starter motor reduction gear is missing a shaft? Or does it just actually magically hang out in between the stator and motor gear?

Also the 17" wheel has a tubeless tire on it. I got it halfway off, but damn does it not want to go the rest of the way.

News:

Author Topic: Rip Van Winkle; Waking up a K4 (Read 9384 times)