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Neat, I bet that looks great in profile. How did you decide on lengths and angles and things for the pipes?
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Jul 12, 2021 02:32
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ought ten posted:Neat, I bet that looks great in profile. How did you decide on lengths and angles and things for the pipes? Honestly like a lot of things that aren’t crucial to the function of the bike, just by eye. There was a lot of layup and looking at it over and over again. Trying to see what made sense and what looked good.
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Jul 12, 2021 02:45
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It worked
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Jul 12, 2021 13:52
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So I'm trying to order the new cam but apparently they are all going to be backordered for who knows how long. But I'm thinking that its going to need something like a 363a. I'm probably just going to leave it as is until I can get the cam. But in the meantime my other head with the stainless valves is going to get blasted and painted so it will be ready to go on. http://webcamshafts.com/pages_vehicles/motorcycle/honda/641.html
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Jul 13, 2021 14:20
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Well it just never ends. Bike has been running and riding just fine for the past month. But today it started to skip in first gear which the other motor had also done. So I tore the other motor apart but didn’t find anything obviously wrong with the transmission. In fact it looked totally fine even though that motor ingested a bunch of metal.
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Jul 18, 2021 04:46
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So Matt started getting the seat done. It will be so nice to actually have a seat on it again. Its going to have leather on the sides and newbuck on the top as it looks a lot like velvet. But its much more durable and doesn't fade nearly as bad.   I think the issue with skipping is that its actually jumping out of gear in first. Which is not good, since if it really is an issue with the trans that means at the very least I have to split the cases and leave the top end on. But worse case the whole motor has to come apart. I still don't know what it could really be since the other motor had the same problem and I cannot find anything wrong with its transmission.
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Jul 22, 2021 15:46
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Well the saga continues. I went over the bike with a fine tooth comb today. Somehow the back sprocket had come loose! Which is insane since it was tightened down big time with lock nuts. So I figured my issue was obviously being cause by that. Tightened everything up and rode it around some more annnnnnnnnnnnnnd still doing it. I’m going to pull the trans cover off tomorrow. And see if I can find anything.
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Jul 25, 2021 01:54
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Is there something wrong with the chain length/chain tension/rear wheel alignment?
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Jul 26, 2021 00:12
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40oz of fury posted:Is there something wrong with the chain length/chain tension/rear wheel alignment? It all seems to be normal as far as I can tell. I did sort of find something that I need to look at. Apparently the neutral switch is what holds the shifter drum in place. If its not there or loose or messed up it can cause the shifter drum to move around. The other motor had damage around where the neutral switch rides so I'm wondering if that has something to do with it. There is a video that shows what happens without the neutral switch in place.  https://www.youtube.com/watch?v=pi5rZyju6yw&t=1948s
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Jul 26, 2021 17:17
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Interesting, certainly seems that if the shift drum is able to move the shift forks will be mis-aligned and won't hold the gears engaged. I'd say you're definitely on the right track.
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Jul 27, 2021 14:48
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Well once again the motor is coming out. I tried to ride to a show today down south and at some point I stopped and clicked into first and the trans completely locked. Whats weird is the motor was still running, but the pulling the clutch in did not let me move the bike. So the motor was not connected to the trans but somehow the trans was just stuck. The only way I was able to get it unstuck was to violently rock the bike back and forth. After that I just rode home using 2nd and up and did not have any other issues. So I assembled the trans in the other motor that had a similar problem. What I found was that it didn't fully want to go into first sometimes. But when this happened I was able to rotate the shifter drum by hand and get it fully into first. I really don't understand what would cause this. But I guess my suspicion is a bent first gear shifter fork. Valt fucked around with this message at 03:06 on Aug 1, 2021 |
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Aug 1, 2021 02:11
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Well I finally pulled the motor apart to get at the transmission. I found that #1 shifter fork is all burnt up which I don't really understand. After talking with Ken at cyclexchange he told me that the shifter forks just move the gears and don't hold anything in place. So that means that the gears were trying to back out and pushing on the first gear shifter fork. I'm currently getting a complete transmission from cycle x and hopefully this issue doesn't happen again. I have a suspicion that the chain was to tight and that worsened this problem.  
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Aug 5, 2021 22:21
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You sure you aren't missing an inter-gear washer or something like that? Honestly looks like the gear was trying to dig into it at an angle.
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Aug 6, 2021 03:12
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Slavvy posted:You sure you aren't missing an inter-gear washer or something like that? Honestly looks like the gear was trying to dig into it at an angle. There is no washer there, where that fork sits the gear has a little lip for it to push on. For it to be burnt up like that means that the gear was trying to push out while the fork was engaged. I'm super not inclined to put a transmission in there till I know roughly why thats happening. Because that is basically two motors now that seem to have similar issues. Here is the parts fiche for a 78' cb750 which you can see there are no washers in there. https://www.bikebandit.com/oem-parts/1978-honda-cb750k/o/m9458#sch400265
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Aug 6, 2021 15:22
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Yeah, something in there was certainly mis-aligned, or there was an unexpected force. I would love to see if you can compare the broken one with the new and figure out for certain what the problem was, just so we have some closure. Is it possible for the shift drum to go too far "in"? I'm not super impressed by the whole assembly being held in by the neutral switch. Is there any indication of a problem with the dogs? I guess that could cause a lateral load.
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Aug 6, 2021 15:36
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Well the transmission that I bought from cycle x should be here on saturday so hopefully I can get it all back together. I'm going to get everything back together and make sure its all good. Then its probably going to come apart for paint. I got all the paint for it and got a 2 gun devibliss gun setup. I also got the gold leaf and spray adhesive, which I'm going to do some test runs to make sure the adhesive doesn't react with any of the paint. This was just a small test with the adhesive and gold leaf. But this is the texture that I am after. My friend is going to print me some vinyl overlays so that I can use those as a mask when I get serious and do the actual designs. I also sold my Dyna recently so I have been working on the other honda chopper that I have. I know nothing about this frame other then its probably setup to be a digger of sorts. I'm currently trying to find a narrow springer for it. But I already have a 21" front wheel and the rear is a honda hub laced to a 4" wide 16" harley rim. The front end thats on it now is just schedule tubing tacked to the triple tress so I could figure out how long it needs to be. Also the bars are just the random ones it came with and not what it have. The tank is a ness style tank and is one of the coolest things about this bike, they are NOT easy to come by.    I'm mostly building this one to sell. I plan on painting it myself and it will be a dark green with some flake and probably gold leaf outlining. This bike will be more along the lines of this.  Except obviously my frame doesn't have a gooseneck and won't be that extreme.
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Aug 13, 2021 19:57
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Well I got the transmission from Ken and cyclex the other day and its in perfect condition. I started putting everything back together and noticed a couple of things. The primary chains appeared to be worn differently and one was looser then the other. Plus the cam chain had apparently been hitting the cases a bit. So I ordered new primary chains and cam chain. I now have to take the entire top off, the only saving grace here is because the crank is out I don't need to take the pistons out to pull the jugs.  I'm STILL trying to get my head back from the machinist, who has had it for like 5 months now. Its been done for like 2 and he has not responded to me several times and told me he would leave it at one of the shops he does work for. But I really want to put that head on since it has good valve guides and stainless valves. I still can't get a new cam since they are all still back ordered. But at least I would have a known good head on it.
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Aug 24, 2021 16:27
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what the gently caress is going on with that output shaft? is it just me or does it look chewed all to hell?
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Aug 25, 2021 04:56
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GnarlyCharlie4u posted:what the gently caress is going on with that output shaft? It just has paint on it and it’s dirty on the end.
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Aug 25, 2021 13:58
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Well I FINALLY got my cylinder head back. But he didn't get the last caps for it that he told me he would get and more importantly he didn't fix all of the threads that I paid him already to do. So now its going to a local machine shop to get media blasted and they are going to fix the other holes and check the head for flatness. I should be able to put the bottom of the motor back together this weekend though. I need to get the lash caps and replacement valve guide seals for that other head as well. I took the valves out before I brought it to the machine shop and noticed that it only has valve guide seals on the intakes. Which makes sense since they are the only ones that would ever see vacuum. Just to be clear the exhaust valve guides are not designed to take seals. Unfortunately I can only get packs of 8 from kibblewhite and they have to come from there since these valves are 5mm not 6mm like stock valves. The lash caps and seals are like $150 plus shipping.
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Aug 27, 2021 16:43
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Well its very good that I took the motor apart I pulled the pistons out of the bores and found that the clips that hold the wrist pins had popped out of their grooves. Upon further inspection it appears that the wrist pins were about a thousandth too long causing the clips to not be able to seat. For what ever reason 3 of them were like this and the 4th was fine. I took the wrist pins over to my friends and we used his lathe to cut them down a tiny bit. I finally got the bottom end mostly together after pulling the top off to put the cam chain and primary chains on. Now I'm just waiting on a oring to arrive then I put the cases together for good. 
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Aug 29, 2021 03:30
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whew you dodged a bullet with those wrist pin clips. That trans looks so good too. Those chains, and gear faces are just so clean.
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Aug 30, 2021 05:12
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GnarlyCharlie4u posted:whew you dodged a bullet with those wrist pin clips. Yeah Ken at cycle x did not do me wrong there. This motor is becoming more and more stupid at this point. So far it has the following: New trans and shifter forks (200) New primary chains (120) New cam chain (89) New clutch (89) Over bored cylinders with forged 836 pistons (489) (labor: 400) 5mm stainless valves (this was actually free since they were already installed in that head) Kibblewhite springs (again came with the head) ARD Magneto (500) Weber carbs with mount (800) Gaskets with MLS head gasket (150) $2850, oh god I think I just died inside.
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Aug 30, 2021 16:50
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Valt posted:Yeah Ken at cycle x did not do me wrong there. This motor is becoming more and more stupid at this point. So far it has the following: I think about 8 years ago I priced out all the motor work I wanted to do. It came out over seven grand and I was like... welp. Better start saving. I still plan to do it to some extent though. Since then I'd picked up like 6 more CB750's that I still need to get through first. Nothing major, just full inside out budget restorations, no fancy parts, overbored jugs, oversized valves, etc... At this point that built motor is going to be my retirement gift to myself. I'll probably get some of the rest of the build done in the meantime though.
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Aug 31, 2021 19:42
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Well the cylinder head is FINALLY done. I got it back from the machine shop and took it to a guy to have it vapor blasted. It looks really clean and its ready for paint and clear. My lash caps and valve guide seals came today to and I went to check that the lash caps would work. But of COURSE those valves are NOT 5mm they are the stock 6.5mm stems, though they are still stainless valves. So now I have to send those lash caps back and order correct valve guide seals. 
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Sep 2, 2021 22:48
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wow that head looks amazing but omg that sucks about the lash caps
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Sep 3, 2021 14:32
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That head does look great, better than scrubbing for hours with steel wool too. Are you going to use wax or anything to keep it nice?
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Sep 3, 2021 15:08
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Shelvocke posted:That head does look great, better than scrubbing for hours with steel wool too. Are you going to use wax or anything to keep it nice? It's going to get painted like the rest of the case with aluminum colored engine paint. You can't keep that cast stuff bare like that as it will quickly corrode. Which is why they painted and clear coated it from the factory.
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Sep 3, 2021 15:13
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I guess that settles whether I'll be repainting the xl125 engine. It's just kind of a faff.
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Sep 3, 2021 18:03
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Well I finally got the head back on and started to put the cam in. But three of the cam cap bolts instantly stripped their holes. So I took it back to the machine shop since he had ran a tap through them and thought they were fine. I’m supposed to get it back tomorrow morning. So I should have it all the way back together tomorrow fingers crossed.
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Sep 9, 2021 04:41
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Well everything is back together and the bike has been running pretty good. I'm not sure why but it smokes on startup but clears up almost instantly. I think this is just a valve guide thing but I am not positive. I rode it on the highway for about 30 minutes the other day and it seemed totally fine. But on the way back when I was on mopac heading northbound just before the 2222 exit. The bike just straight died at highway speeds. I didn't hear anything catastrophic happen and all the cylinders were definitely dead. But the more pressing thing is there is ZERO shoulder at that point on mopac. I didn't have enough momentum to roll the bike off the highway and I got stuck just before the exit. I ended up having to call 911 so I could get police to escort me off the highway. After that whole stupid adventure I pulled the mag cover since I assumed the belt had jumped off or broke. Once I pulled the cover I realized that the lower pulley's set screws had come loose causing the mag to just not work. So it put it in the back of the truck and brought it home. I pulled the pulley off and saw there wasn't any damage. So I put loctite on the pulley and the set screws and it started right up.
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Sep 27, 2021 00:49
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could be valve seals. I had the same problem on a freshly rebuilt motor. Cyl #1 always smoked. The seal looked fine but I swapped it anyway and never had a problem after. Good call on not trying to start it and ride it after it died. That would have sucked to damage that mag.
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Sep 28, 2021 01:23
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GnarlyCharlie4u posted:could be valve seals. I had the same problem on a freshly rebuilt motor. Cyl #1 always smoked. Yeah that head only has intake valve seals as it has stainless valves and the exhaust guides are not meant to have seals. But the seals I put on I pulled from another head, which they were new. But maybe I messed them up a bit pulling them off. I have another brand new set of guide seals so I'm going to try putting those on at some point.
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Sep 28, 2021 15:07
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I have begun the never ending process of blending the welds on the exhaust. Only the two outer pipes will really be a pain since they probably have 6 seams just at the one section. But a lot of the original welds were a bit sunk so I have go back over them and add a bit of filler rod. The tubing polisher definitely makes this process a lot less painful. But its still extremely time consuming.  
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Sep 29, 2021 20:14
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Well this weekend I rode out to COTA to check out the moto gp race. Bike ran fine and without a hitch on the way out there. But on the way back after I stopped for gas I looked down (I have had issues with the bolt that holds the front sprocket on coming loose) and noticed that the front sprocket bolt was loving gone.  I ended up just having triple a take it back home as it would have taken me forever to get the truck and pick it up. I posted this on instagram and several said that had the same problem with this specific sprocket setup. What they suggested was to drill a hole in the M8 bolt that holds the sprocket on and safety wire it to the two 6mm bolts that can thread into the sprocket (these holes are for the earlier 750 front sprockets since they use a big locking tab to hold the sprocket on). This is not the first time this has happened with this setup on this bike as well. I had all of the correct washers per the parts fiche and I torqued that bolt down to 50 ft/lbs.
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Oct 4, 2021 14:57
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Valt posted:Well this weekend I rode out to COTA to check out the moto gp race. Bike ran fine and without a hitch on the way out there. But on the way back after I stopped for gas I looked down (I have had issues with the bolt that holds the front sprocket on coming loose) and noticed that the front sprocket bolt was loving gone. I have had that poo poo happen to me all the loving time. It's just a poo poo design. Blue loctite usually works, but... you know it's blue loctite. Drilling the socket cap screws is a pain-and-a-half unless you've got a vise+drill press and even then, you need a proper hardened drill bit to get through that bolt. If you can find the bolts with the holes already in them for the safety wire then DEFINITELY go that route. They're usually cast that way and hardened accordingly. Drilling holes in the head of a socket cap screw significantly reduces the strength. I've never managed to break one, but I've also never tried.
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Oct 5, 2021 16:35
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GnarlyCharlie4u posted:I have had that poo poo happen to me all the loving time. It's just a poo poo design. I have a floor standing drill press so I drilled a hole in the replacement bolt and in the two 6mm bolts. I used some stainless spring wire until I get some safety wire. Also I used loving red loctite, I'm done loving around with this nonsense. Just to touch on putting a hole in the head of a bolt. That is not going to significantly reduce its strength especially in the use case that the sprocket bolt is. The bolt doesn't really hold the sprocket it just stops it from coming off. So there really shouldn't be much pressure on it ever. If there was it would have immediately come off as soon as the bolt was gone. Valt fucked around with this message at 21:31 on Oct 5, 2021 |
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Oct 5, 2021 18:05
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Valt posted:I have a floor standing drill press so I drilled a hole in the replacement bolt and in the two 6mm bolts. I used some stainless spring wire until I get some safety wire. Also I used loving red loctite, I'm done loving around with this nonsense. oh yeah totally. I meant specifically for those 8.8 grade (or softer) socket cap screws, not the bolts. And not so much a concern for it's ability to function as a bolt, but more so when trying to remove it. and  red locktite
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Oct 6, 2021 16:54
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I forgot to put up the couple of pictures I took from COTA. I like the track but they really need to have shaded areas out there. On a sunny day it is extremely brutal to be out there as there is basically no shade at all. I definitely got some very funny looks riding into the motorcycle parking. Since obviously its almost 100% newish sport bikes. At least it was easy to find my bike in the parking lot.  Also you can see my solution here, I'm actually using stainless spring wire which is why it doesn't look neat and tidy. I'm ordering some actual safety wire so I can do it up nicely. 
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Oct 7, 2021 16:03
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Well my fix for the sprocket has seemed to work so that is good. I am finally tired of dealing with this modified panhead oil tank. It really doesn't fit the space very well and the chain is hitting it and eventually its going to leak horribly. Also all of its connections are just bare smooth chrome tubes so oil constantly blows past them. My buddy came over and we knocked out a paper pattern to build a custom oil tank.  I bought some electric sheet metal shears before I started this and it made cutting the sheet metal a trillion times easier. We just made a pattern for the outer shell since can use that to create the other patterns. We got the rough cut sheet metal bent up last night. Now I just need to fine tune the shape then get the top and bottom cut out and fit in place. I will get everything tacked into place and verify its going to work.  I'm going to order AN adapters for the cb750, so I can use actual oil lines on it. https://www.ebay.com/itm/1837283085...LRoCJAwQAvD_BwE Bung King sells a nice bung kit for oil tanks so I'm going to get that ordered as well. That way I can use nice chrome AN fittings for my oil lines. https://www.bungking.com/oil-tank-bung-kit/
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Dec 8, 2021 17:41
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