Author Topic: smpls '72 750 project (Read 12070 times)

smpls70 · « **Reply #50 on:** September 26, 2010, 10:34:07 AM »

anyone ??

smpls70 · « **Reply #51 on:** October 06, 2010, 12:18:08 PM »

OK,......... rebuilt the carbs, again. these things are so clean you could eat a steak off 'em,. put the needle clip in the 3rd position down from top, floats are set at 26mm, air screws turned 1 turn out ,put a new honda brand filter in the air box, and this beast still does not want to start ! Going to double check points gap, and try another set of plugs, just pulled out 1 & 4 and they were pretty black.Cant do timing until the bike is running of course.

smpls70 · « **Reply #52 on:** October 06, 2010, 02:10:55 PM »

MasterChief750 · « **Reply #53 on:** October 06, 2010, 02:33:39 PM »

theres directions in the service manual to static time the engine to get ou close have you tried that? the light can be made with a led and some aligator clips from radio shack.

rickmoore24 · « **Reply #54 on:** October 06, 2010, 02:43:53 PM »

Yes static timing usually is close enough to get these bikes going. Does it stall on you with the throttle open or during idle. If it's at idle you might want to make sure your idle screw is set to hold the carbs open that little bit it needs to stay firing. Good luck!

Rick

bikerbart · « **Reply #55 on:** October 06, 2010, 03:42:01 PM »

off subject but,that is a cool electric frankenstein poster.I see others as well.Do you own a bunch,or is that photo from a gallery??I collect rock posters,as well as cb750 stuff.

smpls70 · « **Reply #56 on:** October 06, 2010, 04:28:41 PM »

Quote from: bikerbart on October 06, 2010, 03:42:01 PM

off subject but,that is a cool electric frankenstein poster.I see others as well.Do you own a bunch,or is that photo from a gallery??I collect rock posters,as well as cb750 stuff.

Yeah, forgot about that pic, its a Stainboy print 90/200, have a few by him, I have a really cool Nashville Pussy poster he did hanging in the downstairs bathroom, I should post it

.

smpls70 · « **Reply #57 on:** October 06, 2010, 04:39:41 PM »

Quote from: masterchief1112 on October 06, 2010, 02:33:39 PM

theres directions in the service manual to static time the engine to get ou close have you tried that? the light can be made with a led and some aligator clips from radio shack.

So, want to be clear, you first do the point gap adjustment, then static ? I was reading how you hook up 1 clip to the yellow wire, and ground the other, turn the power on , rotate the crank.............this is where im cornfused as to where/ what to do when and if the light comes on. If the light does not come on at the F mark, then rotate the plate forward/backward ?

smpls70 · « **Reply #58 on:** October 06, 2010, 08:15:23 PM »

btw, this thing is frackin' awesome

MasterChief750 · « **Reply #59 on:** October 07, 2010, 07:28:18 AM »

you want to adjust it so that when you are on the fire mark for either pair of cylinders the light should turn off when the breaker opens. if you get to the fire mark and the light syats on your timing is off, adjust the plate to where they are timed correctly. once you get it going you can use a strobe light to adjust timing closer to where it hould be.

smpls70 · « **Reply #60 on:** October 08, 2010, 10:59:44 PM »

There just wasnt quite enough gas in it to start it up

MorePDX · « **Reply #61 on:** October 09, 2010, 01:58:01 AM »

Keep up the good work! I'm excited to see how it progresses. How's the hand?

smpls70 · « **Reply #62 on:** October 09, 2010, 11:06:04 AM »

Mudhustler , thanks, the hand is solid , amazing how fast those bones fuse together . Im thinking I have a clog in the petcock/ dirty gas tank?,, after reading on how to clean the tank, it sounds pretty easy to to, but at the same kind of a drag. I also swapped out a condenser for the 2 & 3 points, could not get a the timing light to strobe, after switching them out, the bike fired up ,strobe worked , but then the bike killed again, so something is clogging up that fuel line, my best guess at the moment anyway

smpls70 · « **Reply #63 on:** October 10, 2010, 03:33:27 PM »

Yeah,I just took it out for a spin around the neighborhood ,this is what sucks about livin in a urban area, stop sign every other block. If youve read through my posting ,this is my first bike, second motor, I dont think the 1st motor was running all four, this one definitely IS, its kind of intimidating

.
It seams to be idling kind of high, tried backing out the idle screw, doesnt seam to be doing anything , so heres where I have no idea what im doing when it comes to the air fuel mixture screws, if in fact thats what I need to messing with

smpls70 · « **Reply #64 on:** October 10, 2010, 07:56:50 PM »

Took it on a nice cruz, about 15 - 20 miles along the mighty Mississippi river, theres a nice parkway, 25 mph speed limit, it did run really nice, except for that high idle, the idle screw is backed all the way out, not even touching. I was out for maybe 30 minn or so, and when I returned home the headers had a yellow/goldish tint to them . Im hoping this is something simple like the cable has to much tension ? when riding in 3rd gear doing about 25 mph or so, it was at 3000 rpm, took my hand of the throttle and it stayed at that speed,was kinda like cruz control !!! any ideas ??

rickmoore24 · « **Reply #65 on:** October 11, 2010, 09:06:13 AM »

I'm having that problem as well, when the bike is fully warmed up she like to rev high at idle/neutral to almost 3 grand, no matter how much I back out the idle scew, it climbs back up. No vaccum leaks, timing is set correctly, air/fuel screws are dialed, proper back pressure, carbs rebuilt......I've tried it all. The only thing left to do it an honest to goodness carb synch with a carb tuner (had it bench synched to get it running right after the rebuild) . If that doesn't fix it, then I got nothing.

smpls70 · « **Reply #66 on:** October 11, 2010, 01:31:39 PM »

Quote from: rickmoore24 on October 11, 2010, 09:06:13 AM

I'm having that problem as well, when the bike is fully warmed up she like to rev high at idle/neutral to almost 3 grand, no matter how much I back out the idle scew, it climbs back up. No vaccum leaks, timing is set correctly, air/fuel screws are dialed, proper back pressure, carbs rebuilt......I've tried it all. The only thing left to do it an honest to goodness carb synch with a carb tuner (had it bench synched to get it running right after the rebuild) . If that doesn't fix it, then I got nothing.

Rickmoore , was it bench synched using the 1/8 in. drill bit, thats what I used and thought maybe that was a liltle bit much ? Im going to start with the simple things like checking the boots, throtle cable etc, etc, cause' im no mood to be taking them carbs off AGAIN anytime soon

I also have a pretty nasty oil leak coming out of the oil pan, ( was lucky, the local honda dealer had ONE in stock !!) , so that needs to be taken care of sooner then later ,looks like I can remove it without taking the pipes off , which will be nice

rickmoore24 · « **Reply #67 on:** October 11, 2010, 04:40:11 PM »

Yep, the 1/8" drill bit trick was used to bench sync the carbs. The bike fired right up after that. It idles just fine during warm up then at the proper running temp it starts to idle high, over 2 grand almost 3. I am almost positive that a proper carb synch will aleviate this problem. It's the only thing left for me to do, just gotta buy the tool now. I'll let you know how it goes.

smpls70 · « **Reply #68 on:** October 11, 2010, 05:48:53 PM »

Double checked timing , check ! ,checked to see if cables were hanging up, check,. sprayed wd40 (all I had, no brake cleaner ) on carb boots, no differace, check,. turned in and out air mixture screws , both ways, no differance ,check !!!!!!!!!

pushed down on the top of the carbs and could get it to come down. So i pulled em, in record time, becoming a pro it it

Those opening must have gotten tweaked somewhere in the process of the last rebuild. Gonna try to bench synch a smaller opening . Also noticed that that oil leak is not from the oil pan , but is coming from the oil line , anyone know off hand if there is a gasket that goes inbetween them and the engine ? If memory serves me , dont think there were any gaskets when I hooked them up .

rickmoore24 · « **Reply #69 on:** October 11, 2010, 07:44:46 PM »

The oil lines have rubber o-rings. no gasket that I can recall.

smpls70 · « **Reply #70 on:** October 14, 2010, 04:32:50 PM »

Anyone have any tricks /tips for getting the choke linkage ,or should I say plates to open and close in concert (stereo !!, FM baby ) as soon as i get one side to work , the other gets out of whack ! could this even factor into this high idle issue im having, am also going to do another bench sync , smaller then a1/8 drill bit , as was poster else where, needle clip is in 3rd position down, 72 , 750 . ,657a carbs, #40 slow jet, #110 mains, stock air box .honda filter, 4/2 pipes . advice, ideas

smpls70 · « **Reply #71 on:** October 19, 2010, 06:06:33 PM »

Throttle cable jim, throttle cable

Old75_ratafe · « **Reply #72 on:** October 19, 2010, 10:11:40 PM »

OK there are two adjusters on the choke linkage... when I did mine the #2? (been awhile) held two of the adjusters and it could go either way... or so I thought. One of them is a tad longer and if you reverse them they don't adjust right end up with the one adjusted all the way out and it still not closing the choke all the way.
Another thing is a bench sync is just that just a baseline you need to sync the carbs otherwise they will be off and rev a lot higher once the engine gets hot because they will be letting in to much air. Another thing have you checked your valve lash? Also a little mod I did was to get a small clear fuel filter for a lawn mower and put it inline with the tank to keep the crap out. Plus its a easy way to see if fuel is flowing too.

Great project man keep it up.

smpls70 · « **Reply #73 on:** October 20, 2010, 07:19:22 PM »

Got er' out on a pretty good run this afternoon, very very windy !!!!!!!! Clutch cable is in need of adjustment. Still need to play around with the throttle cable.
Heres the Q?? What is to high for the idle ? When sitting at a stop its @ about 1200- 1500, to much ? While running in about 3 rd/ 4th @ about 30 -40 mph its about 3000, remember this is my first bike , so im not sure if this is normal ? just want to be sure, carbs are bench synched almost all the way closed, flash light method.
Other than that , it ran great, even got 3 of 4 of my turn signals working , no more hand signaling

, No more oil leaks !!!!
Speaking of the turn signals, are they just for signaling? Or are they also a running/marker light in there as well . if I remember correctly when I put new ones in there awhile back there was a dual filament bulb in there?

Old75_ratafe · « **Reply #74 on:** October 20, 2010, 08:59:50 PM »

Quote from: smpls70 on October 20, 2010, 07:19:22 PM

Got er' out on a pretty good run this afternoon, very very windy !!!!!!!! Clutch cable is in need of adjustment. Still need to play around with the throttle cable.
Heres the Q?? What is to high for the idle ? When sitting at a stop its @ about 1200- 1500, to much ? While running in about 3 rd/ 4th @ about 30 -40 mph its about 3000, remember this is my first bike , so im not sure if this is normal ? just want to be sure, carbs are bench synched almost all the way closed, flash light method.
Other than that , it ran great, even got 3 of 4 of my turn signals working , no more hand signaling , No more oil leaks !!!!
Speaking of the turn signals, are they just for signaling? Or are they also a running/marker light in there as well . if I remember correctly when I put new ones in there awhile back there was a dual filament bulb in there?

Warmed up idle around 1200ish is OK. What do you mean running in 3rd or 4th is around 35mph is 3000? You mean cruising speed? If you mean cruising yes 3000 is ok any lower and I will downshift you can run it higher too. I can tell you that you can hit 60 Mph in 3rd gear before you hit the 8k redline.... Don't ask me how I know that

I can also tell you that if you miss your 2nd gear shift at 6k and don't let the engine come down a bit it will nearly throw you off the bike too.

The front two signals have running lights when the headlight is on as well, the rear just blink no running lights, and the rear brake light has a running / plate light.

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Author Topic: smpls '72 750 project (Read 12070 times)