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Discussion Starter #1
Just picked up a 1988 TW200 with 20000km for $900. I've always wanted one but this is the first one I've seen for sale in my last few years of searching. Not a very common bike where I am (Saskatoon, SK) as I've only seen one other one in my city. Been lurking on the forum for a little while and haven't found any posts relating to the hot start issue I'm having.



I've cleaned the carb, it has a new battery, spark plug, plug cap, I checked the valves and adjusted the intake valve a little.



It won't start once it's warm. Starts within a couple kicks when it's cold, drive it around for 10 minutes until it's warm, shut it off and it won't start back up until it's cooled off again. Comparing spark from cold to hot it looks like it has a weaker spark once it's warm. Ignition coil?



It won't start with the electric start. The engine cranks over just fine but I have never had it fire with the electric start. Comparing the spark from the electric start to the kick starter it looks like it has weaker spark with the electric start, leading me to believe that this issue will fix itself once I figure out the hot start issue. Overall I'd say it has a very weak spark when I compare it to any of the other bikes I own. Had a little Honda Z50R that had a lightening storm worth of spark compared to this one.



The previous owners had gutted the exhaust so it's pretty much straight piped. I shimmed up the jet needle a little bit to try and account for this as it was running pretty lean before hand. The shimming helped a little bit, definitely not tuned right though, stutters a bit at mid throttle and doesn't like wide open throttle very much. I assume I need to go up a jet size too.



I want to get it up and running on the road, I just don't trust taking it in traffic and not being able to start it up if it dies or stalls on me. I'm hoping a new ignition coil will fix this but was curious as to your guys' thoughts. New coil is $100 here vs. $30 eBay, I don't want to waste $100 if it's not an immediate solution but at the same time I don't want to wait 2 weeks to get a cheap one off eBay.



Any tips, tricks, or pointers would be greatly appreciated. I look forward to being apart of the forum.



Thanks
 

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I have had two 1987 TWs that didn't like wide open throttle. What fixed it for me was replacing the stock jet, #114, with a brand new jet #114. It worked for both bikes.



As for the start issue, close the throttle when you try to start it. On both of mine it is very difficult to start with the throttle open.



And ditto, I can barely see the spark on both my '87's.



Good luck.
 

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I'd say throttle/idle settings first, then I'd look at getting a new coil. Not sure which are good or not, but I think mikesxs.net might have a coil that will work and is of good quality, usually around $30 before plug wire and cap.
 

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You might want to do a compression test on the cylinder. Once while cold, once while hot. If the readings differ much, or are low, you'll need to look into it. Or do a leakdown test.
 

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Did it have hot start issues before you touched it? I am wondering if the the valves are set tight? Hot start issues can be tight valves. Maybe recheck and verify?
 

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+1 on checking compression hot and cold. Start with basics.

Can be as easy as judging how hard it is to kick over

but a gauge will be difinitive. Most auto parts stores have "loaners" get one that "stabs" in over screws in to sparkplug hole.

Throttle wide open when testing.

Actual numbers are not critical but dramatic differences between hot and cold will tell you something ain't right be it valve adjust

piston rings etc. Takes something like 120 psi to run, 150 psi to run well.

Often easier with a helper to perform this test.

Does the choke make much difference in hot start?
 

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Discussion Starter #7
It had the hot start issue when I got it. I've checked the valves, increased the intake valve clearance a bit so it was at 0.004 in. Exhaust valves was fine. It has yet to ever start once hot, choke or no choke doesn't make a difference. I only ever cold start it with closed throttle and it starts fine. I pulled the plug after a half dozen or so kicks when it's hot and the plug was dry when I assume it should be wet. So that's my new clue as to what maybe be part of the issue. I'll do a compression test later today and see what I get for results.



Thanks for the replies.
 

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In that case, check your tank and carb venting. It might be a vacuum issue, or dirt in the fuel even. When you're having starting problems, try a little bit of gas straight through the plug hole and see if it starts. If it does, look at fueling issues instead.
 

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Another thing you can try when it won't hot start is to pour a little gasoline in the spark plug hole and try starting it.



And closed throttle for hot starts too.
 

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Had a new Honda xr650L awhile back that would act a bit as you describe.It did this hot start crud until I rejetted the carb....in my case a larger main jet.No clue if this help you or not....since the bike is an 88 it very well could be what the riders above are stating......ignition / electrical.Good luck
 

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Discussion Starter #11
Took the gas cap off and took it apart and gave everything a good cleaning, there was some crud in there. Is the keyhole on the cap the breather? Seems to be starting better now, still takes a couple kicks and won't start with the electric start but is starting once hot now. So hopefully it was a vacuum issue then. What would you guys recommend for jetting/ tuning since the bike has a gutted exhaust?



Thanks
 

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To be sure it isn't the gas cap venting, just crack it open or remove it for testing purposes.



I'd still like to see the compression test numbers.



The stock exhaust isn't terribly restrictive, but if you've got a straight pipe it could make a difference.



I, personally would try to go back to stock...everything. Exhaust, carb settings, etc. Yamaha didn't get it perfect for most of us here, but they got it right enough that the bike would start and run. If that's out of the question, well, then you are going to spend some time dinking with it.
Start with the basics: check your airbox seals etc, air filter, condition of the intake boots, vacuum leaks around the boots/carb/intake. Make sure that carb is clean, then start buying parts. I'd start with a replacement stock pilot jet and the next size bigger, a stock main jet and the next size bigger, maybe even in addition the next next size bigger and I'd replace the main jet holder. Tune the carb as described from information found on this site. Good luck!



Also, the folks here are visual. If you want to get us hot and bothered, invested in a subject...pics! We love the TW porn!
 

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Discussion Starter #13
With the cap cleaned out it seems to be starting a little more reliably. Compression test showed 140 psi so that's fine. Probably go pick up some new jets today, it's running better but definitely needs some tuning. Good enough that I'll start taking it out on the road to see how it does on longer trips. It's far from pretty but in good shape for $900. Not a big fan of the light blue plastics but I'll manage, used to have a Yamaha Moto-4 that was the same colour.

 
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