I have a 1989 Yamaha XT 350 with only a few thousand miles on it. The bike has not been riden much in the last 10+ years. I picked it up from my father's house a couple of years ago with the intention of riding it more. The bike has always been hard to crank. But as of last year the only way to crank it was to open the air box (after removing the side covers) and spraying the box with plenty of starting fluid. After several attempts and sprayings, the bike will run pretty well for the rest of the day. However, the next day it requires the same 30 minute ordeal to get the beast going again. I have tried everything I know from draining the carb bowl, to kicking throttle open, closed, you name it.

Tommorrow I intend to pull the bike out of storage (where it has been for a year due to a move) and try to get the bike going again. Does anybody have any suggestions for how to solve my dilemna?

By the way, it is sometimes difficult to crank even when warm or hot (15-30 minutes of kicking). Thanks for all your help, I look forward to your replies.

Travelingman, 4 strokes can be a bear to start when the valves are out of adjustment - especially when the intake valve is too tight. With the valves adjusted to specs, the next item to look at would be the pilot jet. If clogged at all, starting can be tough. Try those and let us know...

Thanks for the information, can you tell me how to adjust the valves? I am a rookie at such things and do not have a owner's manual. Thanks.

Sorry, I've never worked on a Yam 350 and I understand they use a "shim and bucket" type of adjustment. You might try searching this site for tech info on the how-to. Good luck!

There must be a bad bearing if it is hard to crank hot or cold. I would think that a scored piston would be harder to crank hot than cold.

The factory did the hard part, they made chunks of metal into a running engine.
Your job is simple, return the bike to the condition when it left the factory.

- Great advice from a long time car mechanic.

When a thumper is hard to start, often it is a sign of valves that need adjustment.

Time for a tune up!

Adjust the valves.
Clean out the carb. Look for varnish sludge in the float bowl and jets.
Put "gas treatment" into the gas. This really helps once running.
Clean the air filter. Does it look old? Get a new one.
Nice clean spark? Get a new spark plug. $4-5.
Change the oil and filter.

Get that bike back to factory specs and I bet it runs great.

travelingman said:

Special Yamatool for the valve adjustment is pretty much mandatory for correctness. I second checking the valve clearances.

Man...that sounds similar to the problem I have on my XT550, except that it's only if I let the bike sit for a couple days. It'll be a royal PITA to start, but after I get it started (with either a hundred kicks or starting fluid and a few kicks) it'll start just fine the rest of the day...hot, cold, whatever. Even the next day, it'll start with maybe a half-dozen kicks. But if it sits longer than that...back to being a PITA. If I leave the key off and give it a dozen kicks or so, it'll sputter like it wants to start, but then die and not start. I adjusted the valves to spec, and totally went through the carb...adjusted everything per the factory manual. I've changed spark plug and check it periodically...it looks perfect. It runs perfect once it's started and will idle. I read somewhere that these carbs had a condensation problem...I think I tried draining the bowl and starting it...it's been so long that I can't remember how that worked now! LOL

Thanks for all the help. I actually replaced the spark plug and it seems to have helped some already (although the old one looked okay). I would still like to adjust the valves if anyone can tell me how. I pulled he valve cover the other day only to find two cams instead of the adjust screws that I suspected. Thanks again.

Most of my experience tells me the problem is the pilot jet - the small jet in the carb that lets fuel in when you start it. But in order for gas to be sucked through the pilot jet you need a closed throttle and in many cases a choke.

I suppose it could also be the timing or points.

Start at the front of the horsse and make sure you have spark...Then if you do, its the carb if the valves arent out of adjustment (they dont do that by themselves, so I doubt it unless they were always wrong)

So, Id check the pilot jet, starter jet and the main jets for clogs. If it was always hard to start, it probably needs dialing in regarding the jetting anyway.

Your XT350 is shim and bucket valve adjustment. You check the clearances with a cold engine the same as any other bike. But then, if it needs adjustment, you need a shop manual to pick the right shim thickness. After that you either need a special Yamatool to hold the spring up to remove the shim or you can remove the cams and go from there. It isn't easy and if you pick the wrong shims you start over including paying for new ones.

The best bet is to pay a shop to do it. But check the clearances NOW. Your XT350 absolutely will drop a valve or have some other catastrophic failure if you run it with them too loose. I will send you a picture of a perfect exhaust valve sized hole in my piston if you don't think valve clearances change or need careful attention. They won't need to be adjusted often but they must be done when it is time. There is a reason Yamaha specifies intervals for checking them.

As for the carb, it is a bear. I cleaned mine to what I thought were surgical standards and it still behaved like yours. I put it in the shop and they ran it through the parts washer, blew it out with compressed air and ran thin wire through the various orifices. It ran like a top after that. Also, float height can cause starting problems. That also requires a special tool and technique. If you want to save a couple of bucks find a shop where you can just drop off the carb after removing it yourself. But the carb has to be on the bike for the float height adjustment. While it is in the shop ask them if they can find one size larger pilot and main jets for the that POS carb.

With that bike it is sometimes better to suck it up and pay someone with the right tools to do the work. I have decent mechanical skills and did everything from total engine rebuilds to tire changes on mine. But I still paid for valve adjustments and carb work on my XT350. Those motors are fun when they are opened up with rejetting and a pipe. But they are also expensive to maintain compared to something with screw valve adjusters and a rational carb. And a shop or Clymer manual is an absolute must.