Author Topic: hay out there. help with 371engine  (Read 4624 times)

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Offline TXRAT

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hay out there. help with 371engine
« on: April 22, 2014, 07:02:25 PM »
Would really love to know if these were known for having salad crankshafts and rods or not, I don't want to try to refinish them and it be for no reason when I should have been sourcing new parts.

Offline TXRAT

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Re: hay out there. help with 371engine
« Reply #1 on: April 23, 2014, 05:51:52 AM »
the pistons are shot. gotta check cylenders. beleive to be std. bore. biggest spot i checked was 2.873" or 72.974 mm. but gotta check bores yet. BTW the or motor i have didn't  have some stuff. was able to squirt sone can magic  in it's plugs holes and get a comp of left 90psi and the right  started at 60psi and fifteen min lateri tryed again and it was at 75psi that time. stikky rings maybe? hopefully. ps of course i checked to see about pos. valve damage while the magic worked. had case covers, is missing starter, both chains there missing  also.  stator and field coil; missing also. air duct. carbs. sprocket cover,  nope. well here's to better comp #s tomarrow or next day.

Offline guylr

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Re: hay out there. help with 371engine
« Reply #2 on: April 23, 2014, 02:54:29 PM »
Greg, if your piston measurements are accurate then 72.974 is right on spec for a new one. Take the measurement at 10mm above the bottom of the skirt. The bores that start out at 73.00mm (or a few hundreths of a mm more, look for ink stamps at bottom of cylinder liners) so those are what you need to check. Worn out they will be at 0.10mm skirt clearance. I suspect your low compression is due to stuck rings, carboned up valve seats or maybe mis-timed cams.

Guy
Now Retired Yamaha guy. Cut me and I bleed "Cinquasia Red"

Offline TXRAT

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Re: hay out there. help with 371engine
« Reply #3 on: April 24, 2014, 04:02:23 PM »
ya, , they didn't even use a single valve seal on any of the exhaust valves. Like I said I think before I don't know though, this is not working well with my phone. The piston crown had damage to it., the cam chain master link was missing a piece of the center link,I found it in the bottom of the engine. I did inspect all the gears and amazingly it manage to make it there without hurting anything. The lock washer on the end of the crank I'm assuming something to do with the cam gear there, looks about like something I would have done at age 7. Not salvageable at all. plus I believe the piston rods also will be in need ,when I pulled one of the Pistons wrist pins out it had a bit of scoring on it so I looked in the rod and the wrist pin hole also was scored to match. I plan on doing this engine real solid. . And then be able to enjoy a few rides on it a year. Until I'm too old to be able to ride it. . 101 are the numbers on the sleeves the insert into the engine block. I have not had a chance to check the sleeves yet for taper and whatnot. I do plan on reusing them though if even if I have to punch them out a little bit.

Offline guylr

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Re: hay out there. help with 371engine
« Reply #4 on: April 24, 2014, 04:08:30 PM »
Sorry to hear about the hack mechanic work on your engine :(

I'll get you bike in the registry but there's no place to enter spare engines. Should I list it as a runner or not?

Guy
Now Retired Yamaha guy. Cut me and I bleed "Cinquasia Red"

Offline TXRAT

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Re: hay out there. help with 371engine
« Reply #5 on: April 25, 2014, 01:42:40 AM »
sorry didnt even know you replied! not a runner yet. for a while ill have to use the spare motor.  the early number is my frame #. the latet one is my picked spare im using for a bit do you know anything about a  chang in clutch rods between my engins ?  earlyer one is 2 peaces the later is a solid rod  that comes right out of side of case. not the early one with the muti peace one.

Offline dean

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Re: hay out there. help with 371engine
« Reply #6 on: April 25, 2014, 05:11:40 PM »
The clutch push rod on all year & model  TX/XS 500's ( '73- '78 US spec)  is the same solid one piece part , # 371-16357-02-00

Offline TXRAT

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Re: hay out there. help with 371engine
« Reply #7 on: April 26, 2014, 06:03:24 AM »
omg aperntlly the clutch rod is a muti peaces of steal. mine broke at the in the clutch twist, was the hardened tip therst or it was snaped off at the seal. and the rest of the rod was in the case. i.e. 2 peAces ,graded it ot switch and had a 2 inch rod piece of it. figured it out. cleaning the spare up some more and hanging with the boss(ol' lady).

Offline TXRAT

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Re: hay out there. help with 371engine
« Reply #8 on: April 26, 2014, 06:10:48 AM »
big peace in case, little in hand , tiny one in clutch twist i ment. "smart" phone. . .  lier's.

Offline TXRAT

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Re: hay out there. help with 371engine
« Reply #9 on: December 13, 2014, 03:32:29 PM »
Well guys, as most of you know I managed to get it sorted out, and my spare motor in, swapped my home built ignition set up into the motor. I had to think pretty hard about it, and then I remembered that timing pointer might not be the same between the two motors so I went ahead and used the spare motors timing cover right hand side . Running real solid.   Rockford to Durand and back to Rockford , iRan nearly flawless, it is a 74 after all lol!! I'm sure you can tell by the pictures she was ratty enough to win me a ugly bike trophy lmiao!! Sorry, I am beginning the argue with task of sourcing most of the upper parts of the motor so I can repair the original motor back to better than factory.  I know it's a bit off topic but  a 81 xs400special II  do you guys think that trans do you guys think that transmission would be suitable, and work better? I am asking because I might end up having to split the engine cases open and put new bearing shells and rod bearings in it, just to be on the safe side , I don't want to do so much work to the top to the bottom blows out on me.

Offline guylr

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Re: hay out there. help with 371engine
« Reply #10 on: December 13, 2014, 07:21:29 PM »
The XS400 transmission shares almost no parts with the 500 and will not swap in. The 500 transmission is a good one and reliable so you should stick with it. It does share layout and some parts with the RD350 transmission.

Guy

Still using that phone to post on eh? ;D
Now Retired Yamaha guy. Cut me and I bleed "Cinquasia Red"

Offline TXRAT

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Re: hay out there. help with 371engine
« Reply #11 on: December 15, 2014, 02:32:26 AM »
Yeah, I'm still using my cell phone. yeah I really appreciate the info about the TX 400 transmission, I had read somewhere that there was a small modification to make sure your crank cases and it would fit in, I really didn't believe it would be a good idea anyways reading that was only a small increase in overall top speed it it didn't seem like it would really pay off in the end but I figured I would do my homework before I even seriously consider something like that. You guys are a lot of help in this project and I really couldn't be doing it without  all you guys help. I picked up a 400 XS real cheap so I figured I might look into it a little bit. It runs and it would have been sad to tear it down strictly for the transmission but if it would have been a improvement over my original transmission it might have been worth it. But now I know that it definitely would just have been a horrible dumd idea!!!  :)  Hopefully soon I will be able to afford to get all my parts back from all the different people I needed to send them to to repair Springer front end I got mount on my bike.

Offline TXRAT

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Re: hay out there. help with 371engine
« Reply #12 on: December 15, 2014, 02:58:13 AM »
By the way, should I just replace my mirror, at about 105 it seems to not want to stay where i set it at ;) that was a great ride up to durand lol !!!!  BTW I still don't run a speedo, so I asked my friends they said they where all doing about 90mph when I went right past them. It took my buddy on his 440 Kawasaki about 5 minutes to catch up, the Harleys on the other hand well maybe about 2 minutes LMIAO!!!  would like to get a newer model TX if ones out there and close enough for me to get, between actually paying for the bike, and then paying for shipping it's just too damn much money.  unless I had to do absolutely 0 work to it , would totally not be worth it at all to ship. That kind of bike doesn't sound like very much fun to me personally anyways, I've always been into the customizing seen, even if its only a little bit Its still totally cool !!!  Anyways, I got some parts that I took off of it , forks( probably need new springs, and they definitely need new caps. I got them lose but I never took them out because the replacement cost so damn much) front wheel, front disc, brake caliper, the brake hose is crap but the lines and the master cylinder are there I believe the lever is still on it also they're all stock parts. I still have a  alright gauge mount / benzel with out gadges.  I think I still have the headlight bucket and trim ring but they were kinda in rough shape. I never used any of it so I do not know if any of it works but other than the lamp it looks to be in decent shape.