Hi everyone I'm Simon and I have recently acquired a 2001 Bonneville 790. Its pretty much in mint condition but has had a few issues which I hope I have now sorted. The main one is that it's a bit difficult starting the engine from cold. I'm looking forward to the spring when I plan to really start riding the bike but I'd appreciate any pointers that people may be able to offer regarding the cold start issue.
welcome simon from another surrey TOMCC member, although I don't get down there much on a Thurs night due to other commitments
Hi. You need to narrow this down as much as you can, do you have carbs or injection? Do you hear any clicks, wirring etc.does the starter engage? How many goes on the button constitutes hard to start? Where's it kept? Did it come like this? What have you tried / changed?
Hi and welcome to the forum Used to have a 2004 T100 - they can sometimes get a bit grumpy when cold and really enjoy a fully charged, decent battery.
Hi and Thanks for the welcome and the quick responses. I recently bought my 2001 790cc Bonneville which was a pig to start from cold. I changed the coil, HT leads, Spark Plugs and Battery. I tried starting using the choke (fuel enrichment) and without the choke and I checked all the electrics right from the battery, through the starter switch to the starter motor. The bike is fitted with Norman Hyde exhausts and has had the Air Injection pipes removed. The air filter is the original Triumph filter. Symptoms were that even when the battery (which was new) was fully charged I could only get about 4 trys before the battery appeared to be drained. When it turned over with the starter motor, the speed of turnover seemed sluggish. I checked the battery with my muti-meter and it was showing the correct voltage. I began to suspect that the starter motor brushes needed to be replaced. Rather than risk the starter motor on the bike I managed to buy a second hand one on ebay which I stripped down, cleaned out inside, polished the commutator with fine wire wool and reassembled. I then removed the existing starter and installed my newly refurbished second hand one and the battery problem was solved. However the bike still was a pig to start. I researched on line and came upon a company called Raggedmoto who advised me that the problem may be the carbs. Apparently there are 2 sets of jets in the carbs. The main jets and the idling jets. The main jets don't come into play until you reach approximately 33% of throttle so poor starting issues (if caused by the carbs) are usually down to blocked or dirty idling jets. I sent the carbs to them by courier and they stripped them down to their component parts, ultrasonically cleaned them, blew high pressure air through to unblock any fuel passageways, checked the condition and sizing of both sets of jets, checked that the carb heaters were working, and set the float height to the setting recommended by Triumph. They checked everything else on the carbs and returned them to me bench set so that all I had to do was refit them and the bike with very little further adjustment needed, fired up fine. (Main jets are 115's because of the NH Exhausts and the Idling Jets are 40's which I believe is standard for this Bonnie) It will now start when cold but there is a definite knack to it. On my bike the knack is to use zero choke and just a bit of throttle. Turn on the key and the engine kill switch so that the ignition light is on and wait for about 3 minutes before trying to start. This allows the carb heaters to warm up the carbs. Then with just a touch of throttle the bike will start on the 2nd or 3rd try. Keep it revving for 2 or three minutes till the engine warms up and bobs your uncle. Other guys who have posted on web forums report that they have better success with using choke and no throttle. If I try full choke and no throttle the engine floods. The starting is still not instant but I guess I may have a bit more fettling to do but at least I can now start and use the bike. Once warmed up there is no problem.
Hi Simon, welcome in ! You certainly invested time and money in the right order to remedy the hard starting issue with some success and improvement. Was the idling jets stock (40’s) before the carbs was sent in ? Not sure if you’ve read this post on the internet, worth a read come further fettling mate. Hope you get it sorted. https:www.triumphrat.net/air-cooled-twins-technical-talk/375378-norman-hyde-classic-opinions-w-rejetting.html%3famp=1
What you describe is pretty normal for a carbed Bonnie. Full choke and zero throttle until you have overcome the first 10-15 seconds of hesitation and occasional stall. You can then feed in the throttle and it will respond quickly from there on. it is worth checking the cold cranking amp rating of the battery. It should be at least 180 for happy starting.....
Hi and welcome. A very comprehensive post covering your recovery actions. Seems like you really are on top of the initial problems. Now you just need to enjoy your new ride. Oh yes the inmates do love pictures, you can load one using the button next to the "post reply" button, "Upload A File"........ Wessa
Thanks for the warm welcome. Also thanks for the other feeds that you recommend. I'll have to do some late night reading to work out what to do next. Has anybody tried the TTP Fire starter?
Welcome to the Asylum you should fit right in. To keep the inmate's happy we will need photos. Tucker
Hi Simon and welcome to the forum, I used to belong to South Hants TOMCC a few years back, hope you get the bike sorted ready for spring.
Simon Padmore. Welcome to the Family. Better people on here and great helpers. I to am TOMCC but find it to quite. Here they are all BRO'S. You know we the inmates on here will want a picture of your steed. We drool over pictures while Nursey medicates us. Ride Safe Joe.
