Why do XJ's have a reputation for hard cold starts?

I have read many times that the XJ's have a reputation for being hard to start when the weather is on the cooler side, and sometimes after sitting for a week or so even in warm weather. I have two Hondas and have never had that problem. So, I am wondering, what is the issue? Do old Honda CBs with 4 carbs have the same problems--and Suzukis, Kawasakis?

 

I bought my XJ550 brand new in 1985. It was a hard starter in weather below 45 deg F. even brand new. I think it may be because they were tuned lean.

Now that I have tuned the idle mix a little richer, it starts better in colder weather than it did 34 years ago.

 

Mine has become a little harder and I have it tuned lean, so I think I am going to richen it up just a tad and see if it helps. 34 years is a long time to own a bike, but at least you know its complete history.

 

My Yamaha sometimes starts up right away, sometimes not. My Honda always seems to start up without issue, despite me working on it less by a significant account and it sitting a lot longer in between rides. It's hard to directly compare the two, with the Yamaha being an online four and the Honda being a V twin, but one of the things I've read that could be a factor is that the Yamaha has a TCI vs the Hondas CDI. Based on my limited understating, CDI creates a "fatter"spark, which could be a contributing factor to an easier start. I'm sure there's much more to it than that, including the American bikes being jetted leaner. At the end of the day what matters to me is that no matter how much more work it takes to get it started, I'll take the Yamaha every time.

 

My Seca Turbo starts up right away at temps near freezing with Napa 15w40 in the sump. New battery, new plugs, the right choke for the right temp and you shouldn't have issues.

 

The lean jetting that was required in order to meet emissions.
Removing the anti-tamper plugs and adjusting the idle mixture remedies the cold start problem.

 

My Maxim starts easy year round once carbs were rebuilt properly and dialed in via a colortune and vac sync.

 

The fuel enrichment jet in the carb float bowls can get gummed up over a period of time , either pulling float bowls and cleaning out helps ,or giving carbs a "hot shot" sometimes solves this problem. Noticed before went on a long ride bike sat for 3 days , went to start up and was hard to restart , put to to PRI and started right up . My guess fuel level low from heat and evaporation ...this has been this way before I rebuilt the carbs and same after .

 

I've noticed both bikes start better when turned on prime for a few seconds before pushing the start button

 

What is a hot shot?

 

The fuel bowls are open to atmosphere, and the gas evaporates over time. That's why the prime setting exists.

 

A "HOT SHOT" is lift the tank ,pull fuel line off of petcock. Drain all 4 float bowls and close drain screws , get a large syringe a meat baster type is ideal, squirt a 50/50 mixture of Berryman B11 Carb cleaner and Acetone into the fuel line several times , let sit for about 45 minutes and drain float bowls. Reconnect fuel line put tank back in place set petcock to PRI for a minute or so and start bike up . May smoke a little will clear out , doing this saves having to pull carbs sometimes ... the wonderful fuel we use today can turn to gum , the 50/50 mix will usually dissolve the gummed up jet in the bottom of the float bowl. I learned this trick years ago from a really great fellow mechanic , we used to laugh when he filled up he dumped half a pint of acetone into the tank as well. Must have worked all his vehicles had well over 100K on them LOL

 

Thank you for letting me know. out of curiosity would a higher octane help with this or does that have nothing to do with the fuel gumming up? I seem to be having some sort of problem similar to this, just last night I came back home to find out that the petcock was left on the on position.... I do not like that because if it overflows I wouldn't have known until too late.... since this problem the bike `82 xj 650 maxim started then would stall right out. now after a series of these attempts to get the bike to stay running it will not fire up and even run at this point. This learning curve hurts pretty bad. I think me and my carbs need to have a very long heart to heart about functioning properly. Just wondering where can I find new throttle shaft seals, I see people posting about their replacement a lot, however I can not seem to find them online at all.

 

The wonderful fuel we used 40 years ago turned to gum too.
Gas does what gas does regardless of when it was distilled.

 

Your carbs need to be tended to, and octane has no bearing on the issues you are experiencing.
I'll be adding your post to your thred so we can help you get her back on the road.

 

Thank you, I didn't mean to start a new thread. or high jack anyone elses thread. Very new to being a member of a forum. certain levels of etiquette that I need to learn... Obviously.

 

No worries. It just makes it much easier for all of us to keep track of your bike if we stick to that thread.

 

That makes sense. so as far as all of the work that I have had done to the carburetor by the master mechanic, I am just going to assume that none of it was done correctly!!! Yay that's fantastic. Looks like I will be taking a lot of time on this to make sure the carbs are rebuilt a full hundred percent. So as I was wondering in one of my previous responses. Is there a particular website that I can purchase a full carb rebuild kit that includes all seals and such that need to be serviced? Or what do I do for this situation? Any companies that people are aware of that do a really good job with making a kit?

 

I answered that in your existing thread.
over-rev-when-first-started.124313

Unless you take your bike to a mechanic who specializes in Japanese bikes from the 80's, and who is an enthusiast, you'll never get good results. You will get charged though.