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Discussion Starter · #1 ·
I just rode from maine to new york, probably 400 or so miles at sustained 65mph. It was not very hot out but my engine was frustratingly hot for much of the ride and it would die at idle as soon as i came off the highway. I periodically clocked it with a temp gun at 280-300 at the head and much higher in the finned section where the jugs are--- saw 390 at one point. I had proper oil levels (new oil) and removed the bolt at the head to assure there was adequate flow up there. My plugs read a nice tan and they are the iridium equivalent of the stock specced plugs and my jetting is stock. Valves set right before the ride.

My first question: is that normal for a sustained highway ride or problematically high? If not, what on earth can be causing those high temps??

My next question is that i see what seems to be whitish blowby coming out the oil dipstick hole when the engine is running. Is this normal for these bikes or were my rings destroyed by that heat? Cant afford to rebuild the engine and live in a city where i have no work room... ?
 

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65 mph for 400 miles is a pretty work out for a 350 size engine. You might consider adding an oil cooler to it if your going to be running it that hard all the time.
 

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Discussion Starter · #3 ·
When i serviced my engine before my trip, i took compression readings at ~150 psi per cyl. Today the right read as 175 psi (plugs not fouled so probably not from carbon buildup--- dunno why it's up) and the left is down to 110 psi. It runs but it sounds weird, somehow hollower, and i sense a loss of pep in the throttle. I will put some oil down that left cylinder when i can find some and take readings again to verify its rings--- am doing all this work on a sidewalk in nyc without a hardware or auto store anywhere nearby so it takes time to find these things... ?
 

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Discussion Starter · #4 ·
Confirmed that oil in the left cylinder improves compression. There is so much blowby coming out of my crankcase that i am hesitant to do any serious riding.

Can anyone recommend a trusted motorcycle shop within a few hours of the nyc area? One capable of tackling engine rebuilds? I may just have to get this done.
 

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If you have a shop do that rebuild, you're going to pay a pile of cash and take your chances that the guy who works on it (and likely wasn't born when the bikes were current models) has enough knowledge to do it properly. It's not that they are that complicated, they're just different and most shops just aren't familiar
 

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... It's not that they are that complicated, they're just different and most shops just aren't familiar

I found that many shops these days won't even touch these bikes at all. Some of the shop mechanics I have spoken to have never even worked on carburetors before.
 

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Discussion Starter · #8 ·
Thanks. TOOLS, i did install new carb tubes/gaskets before my trip, so its possible they began to leak or the gaskets didnt seal well. I tightened the clamps well but was cautious to not overtighten--- i have caused splits in such tubes by doing that in the past. Will spraying these tubes with wd40 or something adequately test for leaks?

I was hoping someone knew of a vintage-honda-friendly shop or guy working informally with his own machinery. When i was in maine before my trip back to nyc, i ran into an old guy who told me about a vintage honda mechanic working out of his garage who does that sort of thing, rebuilds, etc. The sort of casual outfit that wouldnt charge you an arm or a leg and where the guy specializes in these bikes. but i dont think i can get this bike safely or cheaply back to Maine. My problem is compounded by the fact that anyone in nyc is going to be twice as expensive as somewhere a few hours outside.
 

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I replied to your other thread on this subject and as Tools said you may have had a issue with some of the work you did prior to your trip causing the hot running conditions. I would consider a used engine as an alternative to a rebuild, especially if you have limited work space and are relying on others for the rebuild. A used engine will cost you a third or less than the cost of a rebuilt one from a machine shop or mechanics shop.
 

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Works Engineering in Brooklyn. Michael Green's shop. I know him from racing. They have recently moved the shop and I am not sure where too. The guys at Union Garage in Brooklyn (MC clothing store) would know where to find him or another good vintage shop. Up State in Cooperstown is Bennett Motor Sales and Ray, the owner, does vintage rebuilds over the winters. He does wonderful work and is VERY familiar with Honda 350's.

Who is the old guy in Maine? Just curious as I live there 1/2 the year and have old Hondas.
 

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Discussion Starter · #11 ·
Thanks jacksvintage. I am actually now halfway through tackling the engine rebuild which as been a ton of fun but more expensive than I budgeted for--- always new surprises popping up when you look in side an engine. The guy in Maine I knew of has a business called bike barn but they replied to my request for a quote for rebuild work and they said they don't work on anything older than 1990. I had been under the impression that they did vintage ones.
 
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