Suzuki 2 Strokes

Well, it's been a year now since completing my 1967 Hustler restoration (with much help from y'all I might add), so thought I should torture myself with another basket case.

So, I just brought home a couple of Titan's, of 1970 & 73 vintage, that are both fairly complete. The previous owner had taken the tank and body panels from the 1970, and installed them on the somewhat better condition 1973 chassis. He then rode this setup around for a year or so, until the bike started to run poorly.

I've been working through this cobbled together setup, and have actually got her running a bit better ... but still not up to par. Disassembled the carbs and found the left side pilot completely plugged. Also discovered that the throttle slides were in backwards. Thoroughly cleaned the carbs, checked and reset one of the float heights, and installed the slides in their correct homes ... with cutaways facing towards the air filter side. Engine starts with one kick.

Currently the bike will only do about 60 mph, but at least the clutch and transmission seem okay. Engine is surging and erratically popping, so put the timing light on both plug wires. Left side is a nice stable flash, but the right side is indicating a misfire condition ... in time with the surge I had been feeling. My first mistake was installing new resistor plug cap ... so I'll be changing those out to the recently purchased LZFH non-resistor versions. If I still have the misfire, I'll go digging a bit further.

My bigger worry right now is the posiforce pump. I've bled through from the tank to the left handed bleed screw, and oil flows freely. But, with the engine running, and the posi lever push all the way forward, I'm not getting anything coming through ... eventhough the lines all look full. With engine still running, I loosened off the two pump discharge side banjos and there doesn't appear to be any oil pumping out even at that point. Not sure where to go from there ... any ideas? If I'm not missing anything, I may just install the posi pump from my parts bike.

That brings me to another point I'm pondering. Since I will only be restoring one of these fine bike, I'm tempted to have the 1970 engine, chassis and body panels all put back together as one complete package, since I plan on having either engine stripped down, resealed and checked over. I personnally prefer the 1970 look (ie: tank nut remover), and according to ozebook ... the 1973's were detuned a bit anyways. BTW, I've got a couple of those Mission Plate oil dams on the way ... so this will get fixed when the engine tear down happens.

So, I'll play with the '73 for now ... but dreaming of a full 1970 project with matching frame and engine numbers. And yes, thanks to the forum ... I checked, and was able to purchase ALL the engine crank and outer seals direct from Suzuki, here in Canada.

Comments/Feedback welcome.

Thanks
Bob (Tourmaster)

And here's a couple of photo's. First one is the 1973 chassis, with the 1970 tank for example:


Second one is the 1970 rolling chassis. I also have the 1973 tank oil tank and seat:

Make sure the pump is turning first of all, then does it pump when turning?
I know the rev counter and pump work on the output side of the clutch, so if the clutch is in (disengaged), neither rev counter or pump will work, but I don't know if there's anything else (pin or key) in there too. Someone else wil be along soon with ideas.

Thanks Alan, I'll check that out. I just assumed that the pump would be turning, since the tach is integral and is working just fine. But I'll disconnect and view with the tach cable out of the way, just to make sure.

If the tach is running, the pump is turning.

Since you have 2 engines, maybe you have 2 oil pumps? If so swap one out for the other.

If you get a small air bubble in the lines, so much the better - at least you will be able to see it get pushed through the lines.

Another trick to see if oil is moving through all the lines is to fill the tank with a different color oil.

BelRay is blue. Silkolene is red. I'll switch from one to the other when I refill the oil tank from almost empty.

Fred's (Bloop) rebuild kits are 100% excellent, if your pump is no good.

Thanks ... I'll try the pump off my parts bike.

All that is nice; is the cross-brace on the handlebars square? As in original? If so, those bars are quite rare these days. Good luck with your projects.


Lane

Installed the parts bike oil pump, then purged the lines with different color oil. Lube system now working just fine.

Cleaned the carbs ... found one of the pilot jets plugged. Also noted that the slides were in backwards with there cutaways facing towards the engine. Swapped them back around.

Took the bike out for a cruise, but lots of engine stumbling, with full on bogging at about 55 mph. Brought her back to the shop and hooked my timing light up to both plug wires. Right side had a nice stable flash rate, but the left side was indicating an unstable misfire condition. Took the ignition cover off, and with the shop lights off, noted bright blue spark coming from the left points. Install a new condensor, and both sides now provide a steady flash rate, with minimal sparking at both point gaps.

Took the bike out for another test cruise. Nice stable pulling in all gears up to about 4500 rpms, and was able to reach about 70 mph. But, the engine starts to bog and stumble, like a misfire beyond that point. The center crank seals don't seam to be leaking, as there is no excessive smoking and tranny oil level is staying up. I suppose the outer seals could be leaking, but I thought I'd experience just a bog condition ... not also that apparent misfire like stumble at the higher revs. My Hustler, for example, just had a bog condition when pressed hard ... and was corrected with new crank seals. I wonder if there still might be something else going on here.

I should mention that the off-idle throttle response is slower once the engine is fully warmed up. Also, when not under full load, and the engine is freewheeling a bit going down the road ... there is a bit more popping and misfire like action going on than I would normally expect ...hmmmm. Plugs so far are showing both brown, with minimal soot. I also snipped the plug wire leads and installed new LZFH non-resistor caps. Plugs are new original vintage NGK 77's. Any thought or suggestions?

My first, fast, gut feeling -- It is running rich. What you describe sounds like it is starting to load up at larger throttle openings (aka "4-stroking"). That it gets worse as it warms up to operating temperature is another indication of running rich.

If it were running lean (as, due to a bad crank seal), it would more seem like it was running great, then just running out of power.

I find this to be a good read: http://www.klemmvintage.com/mikuni-tuning.htm